NEET Biology

NEET Biology MCQs on Ageing and Death

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NEET Biology Growth, Repair Regeneration Ageing And Death Multiple Choice Questions

Question 1. The convention of a specialized cell into an unspecialized embryonic type of evil is referred to as :

  1. Differentiation
  2. Dedifferentiation
  3. Transformation
  4. Convergence.

Answer: 2. Dedifferentiation

Question 2. Growth of a cell occurs during :

  1. M-phase
  2. interphase
  3. Both i and 2
  4. Replication.

Answer: 2. interphase

Question 3. Which one of the following can regenerate its limb if lasts by accident?

  1. Crab
  2. Adult frog
  3. Salamander
  4. Tadpole.

Answer: 3. Salamander

NEET MCQs On Ageing and Death Question 4. Regeneration in which animal was discovered for the first time?

  1. Sycon
  2. Hydra
  3. Planaria
  4. Phererima.

Answer: 2. Hydra

Question 5. Which one of the following organs has a high degree of power of regeneration?

  1. Lungs
  2. Kidney
  3. L4er
  4. Spinal cord.

Answer: 3.L4er

Question 6. Ageing is caused by the disappearance of :

  1. Thyroid
  2. Thymus
  3. Pituitary’
  4. Parathyroid.

Answer: 2. Thymus

Question 7. The number of renal glomeruli is reduced to about half in human beings:

  1. 50 Yrs. old
  2. 70 yrs. old
  3. 60 yrs. old
  4. 75 yrs. old.

Answer: 4. 75 yrs. old.

Question 8. Senescence means :

  1. The period of the life cycle when an animal takes its first breath
  2. The time of life cycle when an animal becomes sexually mature
  3. The process of growth of body size by mitotic division
  4. The process of growing old.

Answer: 4. The process of growing old.

Question 9. It has been observed among kidney donors that the only kidney in the body enlarges and performs the function of a lost kidney. This phenomenon is called :

  1. Senescence
  2. De-differentiation of kidney
  3. Blastema
  4. Compensatory’ hypertrophy.

Answer: 3. Compensatory’ hypertrophy.

NEET MCQs On Ageing and Death Question 10.Protein which plays a significant role in ageing is :

  1. Elastin
  2. Actin
  3. Myosin
  4. Collagen.

Answer: 4. Collagen.

Question ii. When the reserve food material is utilized in the body, the process is called :

  1. Anabolism
  2. Degrowth
  3. Ageing
  4. Growth.

Answer: 2. Degrowth

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 12. The branch of developmental biology which deals with the study of ageing is called :

  1. Ornithology
  2. ichthyology
  3. Gerontology
  4. Histology.

Answer: 3. Gerontology

Question 13. During differentiation, cells with the same DNA :

  1. Develop similarly
  2. D4ide at equal rates
  3. Contain different genes
  4. Transcribe different genes.

Answer: 4. Transcribe different genes.

Question 14. Capacity for regeneration is maximum in :

  1. Sponges
  2. Hydra
  3. Earthworm
  4. Tadpole.

Answer: 2. Hydra

NEET MCQs On Ageing and Death Question 15. The gland that shows atrophy and degenerates with the advancement of age and disappears by middle age is :

  1. Thyroid
  2. Pituitary
  3. Prostate
  4. Thymus.

Answer: 4. Thymus

Question 16. The life span of an organism depends on the rate of:

  1. Growth
  2. Regeneration
  3. Repair
  4. Ageing.

Answer: 4. Ageing.

Question 17. Growth of higher animal body takes place by the addition of:

  1. Protoplasmic substances
  2. Apoplasmatic substances
  3. Both  1 and 2
  4. None of the tires above.

Answer: 3. Both 1 and 2

Question 18. Which of the following shows autotomy?

  1. Starfish
  2. Prawn
  3. Wall lizard
  4. All of above

Answer: 4. All of the above

Question 19. A lost leg cannot be regenerated by :

  1. Salamander
  2. Tadpole larva
  3. Crab
  4. Adult frog.

Answer: 4. Adult frog.

NEET MCQs On Ageing and Death Question 20. When the whole body is formed from a body segment, it is called :

  1. Morphallaxis
  2. Epimorphosis
  3. Parthenogenesis
  4. Epigenesis.

Answer:1. Morphallaxis

Question 21. The Father of gerontology is :

  1. Korenchevsky
  2. Hayflick
  3. Trembley
  4. Sachs.

Answer: 1. Korenchevsky

Question 22. A bud-like structure formed at the end of the cut limb of a salamander is:

  1. Blastula
  2. Blastema
  3. Blastumela
  4. Plasma.

Answer: 2. Blastema

NEET MCQs On Ageing and Death Question 23. Parafunctional development occurs in :

  1. Embryo
  2. Foetus
  3. infant
  4. Adult.

Answer: 1. Embryo

Question 24. Reserve cells in the human body occur in the:

  1. Germinal epithelium
  2. Bone marrow
  3. Stratum germinat4um
  4. All the above.

Answer: 4. All the above.

Plant Growth And Development MCQ For NEET Biology

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NEET Biology Basic Features Of Development Multiple Choice Questions.

Question 1. Among the following who is regarded to be the founder of modem mixology?

  1. Aristotle
  2. Newport
  3. Von Baer
  4. Spallanzani.

Answer: 3. Von Baer

Question 2. Olhpungs sexual reproduction resembles their parents :

  1. Structurally hut not luitctlonnlly
  2. Neither structurally nor functionally
  3. Both structurally and functionally
  4. Only functionally but not structurally.

Answer: 3. Both structurally and functionally

Question 3. Out of these scientists who discovered spermatozoa and called them animalcules?

  1. Hippocrates
  2. Aristotle
  3. Leeuwenhoek
  4. Herlwig.

Answer: 3.Leeuwenhoek

Plant Growth and Development Biology NEET Question 4. The study of the development of an organism is termed :

  1. Ecology
  2. Euphonies
  3. Embryology
  4. Eugenics.

Answer: 3. Embryology

Question5.Of the following animals which produces the smallest egg?

  1. Hummingbird
  2. Salmon
  3. Blue whale
  4. American toad.

Answer: 3. Blue whale

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 6. What gives rise to the gametes in multicellular animals?

  1. Zygote
  2. Ectoderm
  3. Mesoderm
  4. Germ cells.

Answer: 4. Germ cells.

Question 7. Which type of cell division takes place in germ cells during gametogenesis?

  1. Asexual
  2. Meiotic
  3. Mitotic
  4. Both and.

Answer: 4. Both 1 and 2.

Plant Growth and Development Biology NEET Question 8. Primitive germ cells or spermatogonia are located in the :

  1. Basement membrane
  2. Layer of germinal epithelium
  3. Fibroelastic epithelium
  4. Stratified epithelium.

Answer: 4. Stratified epithelium.

Question 9. Spermiogenesis is characterized by :

  1. Removal of water from the head of the spermatid
  2. Formation of the spiral body of mitochondria
  3. Formation of acrosome on file top of nucleus
  4. All of the above.

Answer: 4. All of the above.

Question 10. Conversion of immotile spermatids into motile spermatozoa is called :

  1. Spermiogenesis
  2. Hydrolysis
  3. Motilism
  4. Transformation.

Answer: 1.Spermiogenesis

Question 11. The reproduction begins with the formation of:

  1. Ova
  2. Bud
  3. Sperm
  4. Reproductive unit.

Answer: 4. Reproductive unit.

Question 12. During spermatogenesis, meiosis occurs in :

  1. Sperm mother cell
  2. primary spermatocyte
  3. secondary spermatocyte
  4. None of the above.

Answer: 4. None of the above.

Question 13. Prlmiliy spemmlocyle irfrn to :

  1. Sperm he fore limit nutrition division
  2. Sperm nitre the first nutrition division
  3. Spermatogonium which ceases divisions and starts growing
  4. Primordial sex cell.

Answer: 3. Spermatogonium which ceases divisions and starts growing

Question 14.From one sperm mother cell (primary spermatocyte), the number of sperms produced arc :

  1. 4
  2. 1
  3. 8
  4. 16.

Answer: 1.4

Question 15. The spiral sheath of the sperm is formed by :

  1. Nucleus
  2. Centriole
  3. Golgi bodies
  4. Mitochondria.

Answer: 4. Mitochondria.

Plant Growth and Development Biology NEET Question 16. Which of the following does not possess flagellum in the sperm?

  1. Frog
  2. Roundworm
  3. Man
  4. Sea urchin.

Answer: 2. Roundworm

Question 17. The middle piece of the sperm consists of a compact mass of:

  1. Mitochondria
  2. Endoplasmic reticulum
  3. Golgi bodies
  4. Lysosomes.

Answer: 1. Mitochondria

Question 18. A cell formed from cleavage is :

  1. Morula
  2. Blastomere
  3. Blastopore
  4. Blastula.

Answer: 4. Blastula.

Question 19. The diploid number of chromosomes is restored by :

  1. Fertilization
  2. Maturation
  3. Reduction division
  4. Spermatogenesis.

Answer: 1. Fertilization

Question 20. The head of sperm consists of:

  1. Acrosome
  2. Acrosome and nucleus
  3. Nucleus
  4. Mitochondria.

Answer: 2. Acrosome and nucleus

Question 21. Dysmenorrhoea a painful menstruation, is caused by :

  1. uterine tumours
  2. ovarian cysts
  3. Pelvic inflammation
  4. All of the above.

Answer: 4. All of the above.

Question 22. The sperms produce some enzymes known as “Spermiolysins”. These help in :

  1. Viability by sperms
  2. Penetration by sperms
  3. Movement of sperms
  4. Spermatogenesis.

Answer: 2. Penetration by Sperms

Plant Growth and Development NEET Questions Question 23. Fertilizing is emitted from :

  1. Polar body
  2. Nature ova
  3. Immature egg
  4. Sperms.

Answer: 2. Nature ova

Question 24. The process of spermatogenesis is under the regulatory influence of:

  1. Oxytocin
  2. Vasopressin
  3. Follicle-stimulating hormone
  4. Luteotrophic hormone.

Answer: 3. Follicle-stimulating hormone

Question 25. In frogs lie sperm ceased Imm the testis takes (lie the following milk’ to teaeli urinogenital line :

  1. Vasa efferentia. Bidder’s canal,nutrition nephrostome.
  2. vasa efferentia, Bidder’s canal and nephrostome
  3. Vasa differentia. Bidder’s canal and nephrostome
  4. Vasa efferentia. Bidder’s canal and collecting tubule.

Answer: 4. Vasa efferentia. Bidder’s canal and collecting tubule.

Question 26. Oogenesis in Irog lakes place in :

  1. Interstitial cells in the ovary
  2. Germinal epithelium in the ovary
  3. Epithelium in the ovi sac
  4. Squamous epithelial cells in the ovary.

Answer: 4. Squamous epithelial cells in the ovary.

Question 27. Oogenesis can be explained as :

  1. The process of formation of eggs
  2. Growth
  3. Ejaculation
  4. None of the above.

Answer: 1. The process of formation of eggs

Question 28. The process which helps in the formation and maturation of ova is :

  1. Morphogenesis
  2. Organogenesis
  3. Oogenesis
  4. Spermatogenesis.

Answer: 3. Oogenesis

Question 29. Vitelline membrane is secreted by and surrounds the :

  1. Ova or eggs
  2. oogonium
  3. Spermatids
  4. Oocyte.

Answer: 1. Ova or eggs

Plant Growth and Development NEET Questions Question 30. Albumen around the egg of the frog is secreted by :

  1. Egg itself
  2. Follicle cells
  3. Oviduct
  4. None of the above.

Answer: 3. Oviduct

Question 31. The vitelline membrane of a frog’s egg is :

  1. Primary membrane
  2. Secondary membrane
  3. Tertiary membrane
  4. None of the above.

Answer: 1. Primary membrane

Question 32. An egg containing very little of yolk is called :

  1. Microlecithal
  2. Meiolecithal
  3. Telolecithal
  4. None of the above.

Answer: 1. Microlecithal

Question 33. Insect egg in which yolk is present in the centre is called as :

  1. Centrolecithal egg
  2. Hexapoda egg
  3. Megalecithal egg
  4. Telolecithal.

Answer: 1. Centrolecithal egg

Question 34. A jelly layer of the frog is :

  1. Primary membrane
  2. Secondary membrane
  3. Secreted by the egg
  4. Tertiary membrane.

Answer: 4. Tertiary membrane.

Question 35. The animal pole of a frog’s egg can be distinguished by :

  1. Position of polar body
  2. Eccentric nucleus and pigmentation
  3. Eccentric nucleus and yolk
  4. None of the above.

Answer: 2. Eccentric nucleus and pigmentation

Question 36. The active cytoplasm and nucleus of a frog’s egg are confined to :

  1. Vegetal pole
  2. Animal pole
  3. Displaced slightly towards the animal pole
  4. Eccentrically between the two.

Answer: 2. Animal pole

Plant Growth and Development NEET Questions Question 37. The Yolk of an egg in vertebrates is formed in the:

  1. Ovum
  2. Lungs
  3. Liver
  4. Kidney.

Answer: 3. Liver

Question 38. Antifertilizins tire contained in :

  1. Spermatozoa
  2. Ovary
  3. Testis
  4. Germinal epithelium.

Answer: 1. Spermatozoa

Question 39. A human embryo begins to implant when it is blastocyst or has approximately 100 cells. How old is the embryo at this time?

  1. 12 hours
  2. 2 days
  3. 6 days
  4. 2 weeks.

Answer: 3. 6 days

Question 40. Polar bodies are the products of:

  1. Supernumerary sperm
  2. Unequal division of the nucleus
  3. Unequal division of cytoplasm
  4. Cell excretion.

Answer: 3. Unequal division of cytoplasm

Question 41. Eggs which have a sufficiently large amount of yolk and are large-sized are called :

  1. Oligolecithal
  2. Isolecithal
  3. Polylecithal
  4. Telolecithal.

Answer: 3.Polylecithal

Question 42. In the egg of a bird, the shell and shell membrane are :

  1. Porous to 02 and C02
  2. Porous to air only
  3. Porous to water only
  4. Non-permeable.

Answer: 1. Porous to 02 and C02

Class 11 Biology MCQ – Plant Growth and Development  Question 43. The egg of a frog as it is laid in water is a :

  1. Nature ovum
  2. Secondary oocyte
  3. Fertilized egg
  4. Primary oocyte.

Answer: 4. Primary oocyte.

Question 44. Grey crescent is present in :

  1. Fertilized egg of frog
  2. Eye of frog
  3. Brain of rabbit
  4. Eye of cockroach.

Answer: 1. Fertilized egg of frog

Question 45. Microlecithal eggs are those which have :

  1. A large amount of yolk
  2. The average amount of yolk
  3. Gastrulation
  4. No yolk.

Answer: 3. Gastrulation

Question 46. The phase of embryonic development during which cell movement establishes the three primary germ layers is called :

  1. Gastrulation
  2. Blastulation
  3. Cleavage
  4. Inundation.

Answer: 1. Gastrulation

Question 47. Eggs which have no yolk or an extremely small amount of yolk are called :

  1. Alecithal
  2. Polylecithal
  3. Telolecithal
  4. Mesolecithal.

Answer: 1. Alecithal

Question 48. Fertilization :

  1. Activates the egg
  2. Brings fusion of two haploid nuclei
  3. Both and
  4. None of the above.

Answer: 3. Both and

Class 11 Biology MCQ – Plant Growth and Development Question 49. The intermixing of two nuclei and later two gizmos”. K known av

  1. Syngamy
  2. Fertilization
  3. Amphimixis
  4. None of the above.

Answer: 2. Fertilization

Question 50. When the two gametes unite to form a zygote, it won’t:

  1. Haploid
  2. Diploid
  3. Triploid
  4. Tetraploid.

Answer: 2. Diploid

Question 51. Arrange in the correct sequence the stages of development of the fertilized ovum i.c. blaslula zygote (e) gastnda momla :

  1. a. c. b. d
  2. b, a, c. d
  3. b. d. a. c
  4. d. b. a, c.

Answer: 3. b. d. a. c

Question 52. After the sperm enters the egg, the cytoplasm rotates through the:

  1. 180°
  2. 90°
  3. 75°
  4. 60°.

Answer: 1. 180°

Question 53. The process that sets in after fertilization is known as:

  1. Cleavage
  2. Blastulation
  3. Gastrulation
  4. Neurulation.

Answer: 1. Cleavage

Question 54. Substances released by mature eggs of animals to agglutinate sperms are:

  1. Antifertilizin
  2. Sperm lysin
  3. Fertilizin
  4. Cortical granules.

Answer: 3. Fertilizin

Question 55. In teleosts, reptiles and birds, the cleavage pattern is :

  1. Equal holoblastic
  2. Unequal holoblastic
  3. Incomplete meroblastic
  4. Complete meroblastic.

Answer: 3. Incomplete meroblastic

Question 56. Cleavage is a type of division in which the fertilized egg?

  1. Divides repeatedly without growth
  2. Divides repeatedly and grows
  3. Does not divide, simply grows
  4. None of the above.

Answer: 1. Divides repeatedly without growth

Class 11 Biology MCQ – Plant Growth and Development Question 57. Cleavage leads to formation of :

  1. Blastula
  2. Egg
  3. Gamete
  4. zygote.

Answer: 1.Blastula

Question 58. The ratio of nucleus to cytoplasm at the beginning of cleavage is :

  1. very low
  2. very high
  3. Normal
  4. A bit higher than normal.

Answer: 1. very low

Question 59. Grey crescent is the area :

  1. At the point of entry of sperm into the ovum
  2. Just opposite the site of entry of sperm into the ovum
  3. At the animal pole
  4. In the middle between the animal and vegetal pole.

Answer: 1. At the point of entry of sperm into the ovum

Class 11 Biology MCQ Question 60. The development of the zygote into an embryo is called as :

  1. Embryogenesis
  2. Organogenesis
  3. Blastogenesis
  4. Gametogenesis.

Answer: 1. Embryogenesis

Question 61. When eggs are completely divided, during cleavage, into blastomeres, the type of cleavage is known as :

  1. Holoblastic
  2. Megaloblastic
  3. Meroblastic
  4. None of the above.

Answer: 1. Holoblastic

Question 62. When cleavage luirmv pimc’t through the centre of the animal vegetal axis and hlsccl’i both the poles of the egg, the plane of cleavage is called :

  1. Meridional
  2. Equatorial
  3. Vertical
  4. Latitudinal.

Answer: 1. Meridional

Question 63. Spiral cleavage is found in :

  1. Synapla
  2. Amphibia
  3. Nematoda, nnnclida and rotifera etc.
  4. None of the above.

Answer: 3. Nematoda, nuclide rotifera etc.

Question 64. Which of these is the first phase of development during embryogenesis?

  1. Differentiation
  2. Organogenesis
  3. Fertilization
  4. Gastrulation.

Answer: 3. Fertilization

Class 11 Biology MCQ Question 65. After the main organs of the embryo and its embryonic membranes are formed, then the mammalian embryo is called :

  1. Foetus
  2. Morula
  3. Gastrula
  4. Endometrium.

Answer: 1. Foetus

Question 66. The external stimulus which induces cleavage in an unfertilized ovum is called :

  1. Fertilization
  2. Chemotaxis
  3. Paedogenesis
  4. Neoteny.

Answer: 1. Fertilization

Question 67. In birds, cleavage is:

  1. Discoidal
  2. Superficial
  3. Complete
  4. Absent.

Answer: 1. Discoidal

Question 68. An avian blastula is called :

  1. Blastocyst
  2. Trophoblastic
  3. Blastoderm
  4. Foetal blastula.

Answer: 1. Blastocyst

Class 11 Biology MCQ Question 69. A zygote develops into a mature organism by undergoing :

  1. Cleavage
  2. Fertilization
  3. Conjugation
  4. Reduction division.

Answer: 1. Cleavage

Question 70. The solid ball of cells produced during cleavage is :

  1. Gastrula
  2. Blastula
  3. Morula
  4. Polar body.

Answer: 3. Morula

Question 71. Clustering is a protein present in the sperm head of some :

  1. Salmon fish
  2. Birds
  3. Mammals
  4. Frog.

Answer: 1. Salmon fish

Question 72. Blastodisc or germinal disc refers to the protoplasm of the egg, this is restricted to a small area in :

  1. Amphibian egg
  2. Avian egg
  3. Ascidian egg
  4. Mammalian egg.

Answer: 4. Mammalian egg.

Question 73. The type of cleavage shown by centrolecithal eggs is :

  1. Superficial meroblastic
  2. Discoidal meroblastic
  3. Holoblastic cleavage
  4. Both and.

Answer: 1. Superficial meroblastic

Question 74. When the cleavage furrow extends from the animal pole to the vegetal pole and does not bisect the egg equally into two blastomeres, the plane of cleavage is :

  1. Meridional
  2. Equatorial
  3. Latitudinal
  4. vertical.

Answer: 4. vertical.

Question 75. During the development of the human foetus, the blood tissue ‘ starts developing in the 15th week. It starts with the development of :

  1. Blood plasma
  2. Blood platelets
  3. RBC and WBC
  4. Blood islands.

Answer: 4. Blood islands.

Class 11 Biology MCQ  Question 76. The third cleavage in a frog’s egg. is :

  1. Latitudinal
  2. Horizontal Equtilorial
  3. Meridional
  4. Horizontal.

Answer: 1. Latitudinal

Question 77. As a result of cleavages, if blastomeres are symmetrically placed mound the polar axis, the type of cleavage is known as :

  1. Spiral
  2. Discoidal
  3. TO biradial
  4. Radial.

Answer: 4. Radial.

Question 78. Oblique cleavages in egg produce a symmetry known as:

  1. Spiral
  2. Biradial
  3. Bilateral
  4. Radial.

Answer: 3. Bilateral

Question 79. In frog’s egg symmetry wise the type of cleavage is :

  1. Siradial
  2. Spiral
  3. Bilateral
  4. None of the above.

Answer: 1. Siradial

Class 11 Biology MCQ  Question 8O. Gastrulation in ampliioxus is by :

  1. Convergence
  2. Emboly and epiboly
  3. Divergence
  4. Epiboly and involution.

Answer: 2. Emboly and epiboly

Question 81. Complete holoblastic cleavage occurs in :

  1. Centrolecilhal eggs
  2. Telolecithal eggs
  3. Macrolecithal eggs
  4. Microlecithal eggs.

Answer: 4. Microlecithal eggs.

Question 82. Superficial cleavage occurs in the egg of:

  1. Toad
  2. Frog
  3. Hen
  4. Cockroach.

Answer: 3. Hen

Question 83. Spiral cleavage occurs in :

  1. Ampliioxus
  2. Insects
  3. Molluscs
  4. Reptiles.

Answer: 3. Molluscs

Question 84. Discoidal meroblastic cleavage is characteristic of:

  1. Insects
  2. Mammals
  3. Amphibians
  4. Birds.

Answer: 4. Birds.

Question 85. The blastodisc of a chicken egg is equivalent to:

  1. Egg nucleus
  2. zygote
  3. Blastula
  4. Morula.

Answer: 3. Blastula

Class 11 Biology MCQ  Question 86. How many cleavages are completed in the celled stage of a frog’s egg?

  1. Three
  2. Five
  3. Eight
  4. Sixteen.

Answer: 2. Five

Question 87. In frogs, micromeres contain :

  1. A large amount of yolk
  2. The normal amount of yolk
  3. A little amount of yolk
  4. No yolk.

Answer: 4.No yolk.

Question 88. In an isolecithal egg, one would expect :

  1. Meroblastic cleavage
  2. Unequal holoblastic cleavage
  3. Equal holoblastic cleavage
  4. None of The above.

Answer: 1. Meroblastic cleavage

Question 89. A ball of cells with an enteric cavity is called :

gastrula

Iliscoblastula

Morula

Gaslrula.

Answer: 4. Gaslrula.

Question 90. The unit cell of the blastula is:

  1. Micromerc
  2. Mcgamerc
  3. Blastomere
  4. None of the above.

Answer: 3. Blastomere

Question 91. The blastula in mammals is referred to as :

  1. Blastoderm
  2. Blastodisc
  3. Blastocyst
  4. Coeloblastula.

Answer: 3. Blastocyst

Question 92. The primary organizer in Frog is :

  1. yolk plug
  2. ventral lip of blastopore
  3. The dorsal lip of the blastopore
  4. Lateral lip of blastopore.

Answer: 3. Dorsal lip of blastopore

Question 93. Blastopore is an aperture found in :

  1. Blastula
  2. Morula
  3. Gastrula
  4. Neurula.

Answer: 3. Gastrula

Question 94. In frogs, presumptive ectodermal cells show :

  1. Emboly
  2. Invagination
  3. Epiboly
  4. Convergence.

Answer: 3. Epiboly

Question 95. In the vertebrates, blastopore marks the region of the future :

  1. Mouth
  2. Nostril
  3. Anus
  4. Salivary glands.

Answer: 3. Anus

Question 96. Amoeba reproduces by:

  1. Binary fission
  2. Budding
  3. Fragmentation
  4. Sporulation.

Answer: 1. Binary fission

Question 97. The period of development which is passed within the egg or the womb of the mother is called :

  1. Post-natal
  2. Embryonic
  3. Natal
  4. Extra-embryonic.

Answer: 2. Embryonic

Class 11 Biology MCQ  Question 98. When the offspring are developed by budding or fragmentation, the process is called :

  1. Embryogenesis
  2. Organogenesis
  3. Gametogenesis
  4. Blastogenesis.

Answer: 4. Blastogenesis.

Question 99. Malarial parasites multiply by the process of:

  1. Budding
  2. Fragmentation
  3. Multiple fission
  4. Binary fission.

Answer: 3. Multiple fission

Question 100. The constancy of the chromosomes is brought about by a special type of nuclear division is known as :

  1. Mitosis
  2. Meiosis
  3. Amitosis
  4. Parthenogenesis.

Answer: 2. Meiosis

NEET MCQS on Kingdom Monera

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NEET Biology Kingdom Monera Multiple Choice Questions

Question 1. An organism should be placed in the kingdom Moncra if it

  1. Consists of a single cell
  2. Has a cell wall
  3. Is surrounded by a capsule
  4. Lacks a nuclear membrane separating its genetic (material from the cytoplasm.

Answer: 4. Lacks a nuclear membrane separating its genetic (material from the cytoplasm.

Question 2. Newly started rice paddies produce poor crops until -they have established a flourishing population of cyanobacteria. This is probably because:

  1. Die rice needs nitrogen fixed by the cyanobacteria
  2. The rice cannot compete with weeds, which are poisoned by toxins produced by the cyanobacteria
  3. The cyanobacteria use surplus nutrients from sewage in the rice paddies
  4. The cyanobacteria lack proteins in their dna.

Answer: 1. Die rice needs nitrogen fixed by the cyanobacteria

Question 3. A wall-less moneran is:

  1. Bacteria
  2. Blue-green algae
  3. Mycoplasma
  4. Archaebacteria.

Answer: 3. Bacteria

Most Important MCQs on Monera Question 4. Symbiotic nitrogen fixation is found in :

  1. Rhizobium
  2. Oscillatoria
  3. Azotobacter
  4. Nitrobacter.

Answer: 1. Rhizobium

Question 5. Cyanobacteria do not possess :

  1. Gene recombination
  2. Flagella
  3. Plasmid
  4. Lamellasome.

Answer: 2. Flagella

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 6. Pili in bacteria represent :

  1. Extrachromosomal genetic element
  2. Cell membrane outgrowths of donor cells
  3. Small flagella
  4. Special bacterial cilia.

Answer: 2. Cell membrane outgrowths of donor cells

Question 7. Branched-chain lipids occur in the cell membranes of:

  1. Archaebacteria
  2. Mycoplasma
  3. Actinomycetes
  4. Streptomyces.

Answer: 1. Archaebacteria

Most Important MCQs on Monera Question 8. The decomposition of organic compounds in the presence of 02 without the development of an odoriferous substance is:

  1. Nitrification
  2. Decay
  3. Denitrification
  4. Nitrogen fixation.

Answer: 2. Decay

Question 9. The cell wall in all bacteria is composed of:

  1. Lipid and protein
  2. Murein
  3. Proteins only
  4. Cellulose and lipids.

Answer: 2. Murein

Question 10. Genophore is the name of:

  1. DNA of eukaryotes
  2. DNA of protists
  3. DNA of prokaryotes
  4. Genes of drosophila.

Answer: 3. DNA of prokaryotes

Question 11. Micro-organisms in milk are killed by heat treatment at a controlled temperature without altering the natural characteristics of milk through a process called

  1. Boiling
  2. Immunization
  3. Pasteurization
  4. Sterilization.

Answer: 3. Pasteurization

Question 12. Naked dna is that which is :

  1. Not covered by a nuclear envelope
  2. Present in cytoplasm
  3. Associated with histone proteins
  4. Not associated with histone proteins.

Answer: 4. Not associated with histone proteins.

Most Important MCQs on Monera Question 13. In the bacterium Bacillus subtilis the cells often become attached from end to end forming long filamentous chains, which are embedded in a mass of mucilage forming a scum layer on the substratum. It is called as:

  1. Palmella stage
  2. Torula stage
  3. Zoogloea stage
  4. None of the above.

Answer: 3. Zoogloea stage

Question 14. Prokaryotic chromosome is :

  1. A naked double-stranded
  2. A single-stranded circular dna
  3. Composed of DNA or RNA
  4. Associated with non-histones.

Answer: 1. A naked double-stranded

Question 15. Bacteria resemble yeasts because both have property

  1. Degradation of food
  2. Binary fission
  3. Anaerobic respiration
  4. Sexual reproduction.

Answer: 2. Binary fission

Question 16. One of the following does not apply to Escherichia coli:

  1. Transformation
  2. Transduction
  3. Flagella
  4. Diploid.

Answer: 4. Diploid.

Question 17. Which of the following are intermediate between viruses and bacteria?

  1. Mycoplasma
  2. Spirilla
  3. Cyanobacteria
  4. Variola.

Answer: 1. Mycoplasma

Question 18. Bacteria are found to be primitive organisms because they:

  1. Are small, microscopic which are not seen with the naked eye
  2. It causes serious diseases in human beings, domesticated animals, and crop plants.
  3. Produce endospores which are very resistant to adverse conditions
  4. Possess incipient nucleus and show amitotic division.

Answer: 4. Possess incipient nucleus and show amitotic division.

Question 19. Ih bacteria the most resistant stage is:

  1. Capsuled vegetative cell
  2. Newly divided cell
  3. Endospore stage
  4. Torula stage.

Answer: 3. Endospore stage

Most Important MCQs on Monera Question 20. Some diseases caused by bacteria are:

  1. Measles, mumps, malaria
  2. Tetanus, typhoid, tuberculosis
  3. Smallpox, sleeping sickness
  4. Poliomyelitis, psittacosis

Answer: 2. Tetanus, typhoid, tuberculosis

Question 21. bacterium which is commonly present in the intestine of man and animal is :

  1. Vibrio comma
  2. Escherichia.
  3. Script
  4. Pseudomonas citri.

Answer: 2. Escherichia.

Question 22. The chemotherapeutic substance derived from a living organism that has an inhibitory effect on parasitic organisms is known as:

  1. Exotoxin
  2. Antibody
  3. Bactericide
  4. Antibiotic.

Answer: 4. Antibiotic.

Question 23. Bacteria are plant-like because they have :

  1. Rigid cell wall
  2. Ability to reproduce
  3. Both the above
  4. None of the above.

Answer: 1. Rigid cell wall

Kingdom Monera NEET MCQ Question 24. In transduction :

  1. Bacteriophage transfers dna from donor to recipient cell
  2. Extracellular dna enters the recipient cell
  3. The donor cell survives
  4. The donor and recipient cells survive.

Answer: 1. Bacteriophage transfers dna from donor to recipient cell

Question 25. Gram+ve bacteria have :

  1. Thick and homogeneous cell walls
  2. As much as 70% of peptide molecules
  3. Either no lipids or less than 10% lipids
  4. All the above.

Answer: 4. All the above.

Question 26. Honey, jams, jelly, and chutney are free of bacteria, because:

  1. Bacterial cells are plasmolysed in these substrates
  2. These substrates are poisonous
  3. These substrates have a foul smell
  4. These substrates have complex substances which cannot be utilized by bacteria for their nutrition.

Answer: 1. Bacterial cells are plasmolysed in these substrates

Question 27. Cyanobacteria is a :

  1. Category of bacteria
  2. Is the new name of all bacteria
  3. New name of Myxophyceae or Cyanophyceae or blue-green algae
  4. None of them.

Answer: 3. New name of Myxophyceae or cyanophyceae or blue-green algae

Question 28. Both bacteria and cyanobacteria are :

  1. Prokaryotic
  2. Eukaryotic
  3. Eukaryotic as well as prokaryotic
  4. None of the above.

Answer: 1. Prokaryotic

Kingdom Monera NEET MCQ Question 29. If a bacterial cell is dividing every minute and takes one hour to fill a cup. It will require how much time to fill half of the cup.

  1. 30 Minutes
  2. 60 Minutes
  3. 59 Minutes
  4. 61 Minutes

Answer: 3. 59 Minutes

Question 30. The formation of vinegar from alcohol is caused by

  1. Bacillus subtilis
  2. Clostridium
  3. Acetobacter aceti
  4. Otobacter.

Answer: 4. Otobacter.

Question 31. The formation of vinegar from alcohol is caused by

  1. Bacilius subtitles
  2. Clostridium
  3. Acetobacter aceti
  4. Azotobacter.

Answer: 3. Acetobacter aceti

Question 32. Photosynthetic bacteria have:

  1. Pigment system 1 (only one pigment system)
  2. Pigment system 2
  3. Both
  4. Some other types.

Answer: 1. Pigment system 1 (only one pigment system)

Question 33. Which of the following causes nitrification?

  1. Bacillus ramosus
  2. Nitrosomonas
  3. Nitrobacter
  4. Both 2 and 3.

Answer: 4. Both 2 and 3.

Question 34. Bacteria having a tuft of flagella at both ends tire called :

  1. Peritrichate
  2. Bitrate
  3. Amphitrichate
  4. Lophotrichate.

Answer: 4. Lophotrichate.

Kingdom Monera NEET MCQ Question 35. What turns the wine sour?

  1. Light exposure
  2. Aerobic bacteria
  3. Anaerobic bacteria
  4. High temperature.

Answer: 2. Aerobic bacteria

Question 36. Streptomycin is produced by :

  1. Streptomyces grievous
  2. Streptomyces soleus
  3. Streptomyces fragile
  4. Streptomyces venezuellae.

Answer: 1. Streptomyces grievous

Question 37. Botulism, a type of food poisoning, is caused by:

  1. Rhizobium
  2. Vibrio
  3. Streptococcus
  4. Clostridium botulinum.

Answer: 4. Clostridium botulinium.

Question 38. Fever typhoid is caused by the bacteria :

  1. Xanthomonas typhous
  2. Salmonella typhi
  3. Bacillus diplococcus
  4. Bacillus dysenteriae.

Answer: 2. Salmonella typhi

Question 39. Griffith performed experiments on which bacteria and concluded the occurrence of transformation in bacteria

  1. Bacillus pneumonieae
  2. Salmonella pneumonieae
  3. Diplococcus pneumonieae
  4. Xanthomonas pneumonieae.

Answer: 3. Diplococcus pneumonia

Question 40. Bacteria have flagella around the periphery of the cell. This condition is known as:

  1. Peritrichate
  2. Monotrichate
  3. Lophotrichate
  4. Amphitrichate.

Answer: 1. Peritrichate

Question 41. The estimated length of dna molecule in Escherichia coli is :

  1. 1000 Pm
  2. 100 Pm
  3. 100 A
  4. 1000 A.

Answer: 3. 100 A

Biological Classification MCQ For NEET Question 42. Form of sexual reproduction where genetic material is carried from one strain of bacteria to another by bacteriophage:

  1. Transformation
  2. Transduction
  3. Mesomixis
  4. Conjugation.

Answer: 2. Transduction

Question 43. The structure formed by the bacterial genome is called:

  1. Nucleus
  2. Nucleoid
  3. Nucleoli
  4. Nucleolus.

Answer: 2. Nucleoid

Question 44. Bacteria having a tuft of anger at our CML are called :

  1. Monotridious
  2. Amphitnehous
  3. Cephalotrichoues
  4. Peritrichous

Answer: 3. Cephalotrichoues

Question 45. Staplix kvivcus causes :

  1. Food jvisoniug
  2. Citrus canker
  3. Denitrification
  4. Vinegar fonnation.

Answer: 1. Food jvisoniug

Question 46. Photoautotrophic bacteria contain the pigment:

  1. Chlorophyll
  2. Bacteriochlorophyll
  3. To carotene
  4. No pigment.

Answer: 2. Bacteriochlorophyll

Biological Classification MCQ For NEET Question 47. E.coli lives in the human intestine and causes:

  1. Urinary tract infection
  2. Diarrhea
  3. Meningitis
  4. None of the above.

Answer: 4. None of the above.

Question 48. In e. Coli when the flagella rotates in a clockwise and anticlockwise direction, the movements are:

  1. Jumping and hooping
  2. Running and tumbling
  3. Tumbling and hooping
  4. Hooping and running.

Answer: 2. Running and tumbling

Question 49. A bacterial cell undergoes binary fission every twenty minutes. Starting with a single bacterium how many bacteria will be produced at the end of 3 hours?

  1. 128
  2. 256
  3. 512
  4. 1024.

Answer: 3. 512

Question 50. Which of the following is a free-living anaerobic nitrogen-fixing bacteria?

  1. Azotobacter
  2. Nitrobacter
  3. Rhizobium
  4. Clostridium.

Answer: 4. Clostridium.

Question 51. E. Coli bacterium possesses a single large circular dna as its genetic material. This strand codes for :

  1. 1000-2000 Different proteins
  2. 2000-3000 Different proteins
  3. 3000 To 4000 different proteins
  4. More than 4000 different proteins.

Answer: 2. 2000-3000 Different proteins

Question 52. Bacteria that get their energy from fermentation and for whom oxygen is lethal are called:

  1. Obligate anaerobes
  2. Obligate aerobes
  3. Facultative aerobes
  4. Facultative anaerobes.

Answer: 1. Obligate anaerobes

Biological Classification MCQ For NEET Question 53. The bacteria (treponema pallidum) that cause the v.d. Syphilis are :

  1. Pseudomonas
  2. Purple non-syphilis
  3. Rickettsia
  4. Spirochaetes.

Answer: 4. Rickettsia

Question 54. Which of the following jives in the gut of termites and helps them digest cellulose:

  1. Plasmodium
  2. Trypanosoma
  3. Trichonympha
  4. Trichosomes.

Answer: 3. Trichonympha

Question 55. An example of a chemoautotrophic bacterium is:

  1. Lactobacillus
  2. Nitrosomonas
  3. E. Coli
  4. Rhizobium.

Answer: 2. Nitrosomonas

Question 56. Bag included amongst :

  1. Fungi
  2. Prokaryotes
  3. Bryophytes
  4. Protista.

Answer: 2. Prokaryotes

Biological Classification MCQ For NEET Question 57. Some bacteria produce resting spores during unfavorable conditions. They are:

  1. Exports
  2. Endosporcs
  3. Aplanosporcs
  4. Chlamydospores.

Answer: 2. Endosporcs

Question 58. The similarity between bacterium and cyanobacterium is:

  1. Presence of flagella
  2. Presence of 80 s ribosome
  3. Presence of nucleoid
  4. Presence of phycobilisomes.

Answer: 3. Presence of nucleoid

Question 59. Conjugation in bacteria was discovered by :

  1. Jacob and Wollman
  2. Zinder and Lederberg
  3. Lederberg and Tatum
  4. Beadle and Tatum.

Answer: 3. Zinder and lederberg

Question 60. Archaebacteria found in salty pans and salt marshes are

  1. Methanogens
  2. Thermoacidophiles
  3. Ruminant symbiosis
  4. Halophiles.

Answer: 4. Halophiles.

Most Important MCQs on Monera Question 61. Prokaryotic cells have a volume range of :

  1. 0.2 to 10 pm3
  2. 100-1000 Pm3
  3. 1000-10000 Pm3
  4. 0.01 to 0.1 pm3.

Answer: 1. 0.2 to 10 pm3

Question 62. Prokaryotic flagella possess :

  1. A helically arranged protein molecule
  2. Protein membrane-enclosed fiber
  3. Unit membrane-enclosed fiber
  4. Microtubular (9+2) membrane.

Answer: 1. Protein membrane-enclosed fiber

Question 63. Organisms used in alcohol fermentation are:

  1. Penicillium
  2. Pseudomonas
  3. Aspergillus
  4. Saccharomyces.

Answer: 4. Saccharomyces.

Question 64. Tailed bacteriophages are :

  1. Motile on the surface of bacteria
  2. Non- motile
  3. Actively motile in water
  4. Motile on the surface of plant leaves.

Answer: 1. Motile on the surface of bacteria

Question 65. A large number of organic food molecules can be prepared by:

  1. Chemolithotrophs
  2. Pseudomonas
  3. Azotobacter
  4. Mycoplasma.

Answer: 1. Chemolithotrophs

Most Important MCQs on Monera Question 66. Bacteria were first observed by :

  1. W.h Stanley
  2. Louis Pasteur
  3. A.v. Leeuwenhoek
  4. Robert koch.

Answer: 3. A.v. Leeuwenhoek

Question 67. “Little leaf” of brinjal is caused by :

  1. Bacteria
  2. Mycoplasma
  3. Fungi
  4. Venus

Answer: 2. Mycoplasma

Question 68. Crown gall is caused by

  1. Mycobacterium
  2. Bacteria
  3. Clostridium
  4. Erwinia

Answer: 2. Bacteria

Question 69. Which of the following is an antibiotic?

  1. Chloramphenicol
  2. Ethwphous
  3. Phosphon-d
  4. Amo 11.1s

Answer: 1. Chloramphenicol

Question 70. Which of the following mg is a bacterial disease?

  1. Measles
  2. Tuberculosis
  3. Rabies
  4. Smallpox.

Answer: 2. Tuberculosis

Most Important MCQs on Monera Question 71. An aerobic nitrogen-fixing soil bacterium is :

  1. Rhizobium
  2. Clostridium
  3. Azotobactcr
  4. Rhodospirillum.

Answer: 3. Azotobactcr

Question 72. Hormogonia help in the reproduction of:

  1. Cladophora
  2. Bacteria
  3. Archaebacteria
  4. Cyanobacteria.

Answer: 4. Cyanobacteria.

Question 73. Which one of the following belongs to none?

  1. Amoeba
  2. Escherichia
  3. Gelidium
  4. Spirogyra.

Answer: 2. Escherichia

Question 74. Streptomyces ramosus is the source of the antibiotic :

  1. Chloromycetin
  2. Erythromycin
  3. Aureomycin
  4. Terramycin.

Answer: 4. Terramycin.

Question 75. The cells of cyanobacteria and bacteria exhibit similarity in having:

  1. Nuclei
  2. Centrosome
  3. Plastids
  4. Dna.

Answer: 4. Dna.

Question 76. Bacteria without flagella are known as :

  1. Monotrichous
  2. Lophotrichous
  3. Peritrichous
  4. Atrichous.

Answer: 4. Atrichous.

Question 77. Chromoplasm is part of protoplast in :

  1. Actinomycetes
  2. Myxobacteria
  3. Cyanobacteria
  4. Eubacteria.

Answer: 3. Cyanobacteria

Question 78. Which of the following is not a bacterial action?

  1. sewage disposal
  2. Ripening of cheese
  3. nitrogen fixation
  4. Precipitation.

Answer: 4. Precipitation.

Kingdom Monera NEET MCQ Question 79. The vinegar is prepared from sugary molasses by the activities of:

  1. Fa; diplococcus
  2. FB; acetobacter acetic
  3. Staphylococcus
  4. B. Subtilis.

Answer: 2. Fb; acetobacter acetic

Question 80. Genophore is made up of:

  1. Rna arid histones
  2. Histones and non-histones
  3. A single-stranded dna
  4. A double-stranded dna.

Answer: 4. A double-stranded dna.

Question 81. In rice fields, the soil fertility can be improved by :

  1. Rhizobium
  2. Sod. Chloride
  3. Gypsum
  4. Blue-green algae.

Answer: 4. Blue-green algae.

Question 82. Which it billowing is with denitrification

  1. Uhiobinm
  2. Srudomnuns
  3. Otohacler
  4. Khodospirillum.

Answer: 2. Srudomnuns

Question 83. Which of the following cells is a prokaryote

  1. Bacterium
  2. Virus
  3. Both 1 and 2
  4. Green algae.

Answer: 1. Bacterium

Question 84. Peptidoglycan forms many layers in the wall of:

  1. Gram-ve bacteria
  2. Gram neutral bacteria
  3. Gram -i-ve bacteria
  4. All of them.

Answer: 3. Gram -i-ve bacteria

Question 85. Which era is dubbed the age of prokaryotic microbes?

  1. Palaeozoic
  2. Proterozoic
  3. Precambrian
  4. Archaeozoic.

Answer: 4. Archaeozoic.

Question 86. Sexual reproduction is absent in:

  1. Ulothrix
  2. Volvox
  3. Spirogyra
  4. Nostoc.

Answer: 4. Nostoc.

Kingdom Monera NEET MCQ Question 87. Salmonellosis is the process of:

  1. Food poisoning by bacteria
  2. Reproduction by bacteria
  3. Manifestation of typhoid
  4. Decomposition by bacteria.

Answer: 1. Food poisoning by bacteria

Question 88. Meningitis a disease that is responsible for membrane damage of the brain is caused by :

  1. Neisseria
  2. A fungus
  3. Bacillus
  4. Bordetella.

Answer: 1. Neisseria

Question 89. Which of the following bacterium converts the sucrose into dextrin

  1. Spirillum solutions
  2. Leuconostoc mesenteroids
  3. Bacillus megatherium
  4. Both 1 and 2.

Answer: 2. Leuconostoc mesenteries

Question 90. When bacteria are rod-like and cubical packet of 8 cocci, are called as:

  1. Bacilli and sarcina
  2. Spirilla and cocci
  3. Sarcina and vibrio
  4. Spirilla and sarcina.

Answer: 1. Bacilli and sarcina

Question 91. Whose cell wall dissolves by antibiotic action :

  1. Bacteria
  2. L-form bacteria
  3. Mycoplasma
  4. Actinomycetes.

Answer: 2. L-form bacteria

Kingdom Monera NEET MCQ Question 92. Special taste is developed in the tea leaves by fermentative action of:

  1. Mycococcus candisans
  2. Megatherium micrococcus
  3. Bacillus megatherium
  4. Clostridium acetobutylicum.

Answer: 1. Mycococcus candisans

Question 93. An episome in bacteria is:

  1. Nutritional factor
  2. Sex factor
  3. Cofactor
  4. None of these.

Answer: 2. Sex factor

Question 94. Aureomycin and chloramphenicol are obtained from :

  1. Strcptomyces aureofaciens and s. Ramosus
  2. S. Venezuelae and s.rimosus
  3. S. Aureofaciens and s.fradiae
  4. S. Aureofaciens and s. Venezuela.

Answer: 4. S. Aureofaciens and s. Venezuela.

Question 95. Chloramphenicol ami erythromycin (broad speetmm antibiotics Produced by:

  1. Rhizobium cnieillmm
  2. Strcptomyccs
  3. Niirobnetct.

Answer: 3. Niirobnetct.

Question 96. Spiroplasms arc also walks nipple layered unit membrane-covered orgasms like mycoplasma but they differ from them in being :

  1. Non-infections
  2. Satisfying Koeh’s postulates
  3. Motile and helical filamentous
  4. None of the above.

Answer: 3. Motile and helical filamentous

Question 97. Term spiroplastna was suggested by:

  1. Pavis and Worley
  2. Worley
  3. Davis
  4. Ehrenberg.

Answer: 1. Pavis and Worley

Question 98. Rhizosphere bacteria are present around the;

  1. Leaf surface
  2. Floral surface
  3. Root surface
  4. Shoot surface.

Answer: 3. Shoot surface.

Question 99. A mixture of bacteria, viruses, and mycoplasma is drained through a filter with 450 pore size which of these would not pass through:

  1. Virus
  2. Mycoplasma
  3. Bacteria
  4. All of these.

Answer: 3. Bacteria

Question 100. A chain of spherical bacteria is called streptococci. When spherical cocci are found in grape-like irregular aggregates, they are called :

  1. Sarcinae
  2. Staphylococci
  3. Palisade
  4. Streptobacilli.

Answer: 2. Staphylococci

Biological Classification MCQ For NEET Question 101. A cubical packet of 8 cocci is called:

  1. Staphylococcus
  2. Vibrio
  3. Gaffkva
  4. Sarcina.

Answer: 4. Sarcina.

Question 102. Monerans are plants because they have :

  1. Ability to synthesize vitamins
  2. Rigid cell wall
  3. Both  and
  4. None of the above.

Answer:  3. Both  and

Question 103. “Bacillus thuringiensis is used to control:

  1. Bacterial pathogens
  2. Fungal pathogens
  3. Nematodes
  4. Insect pests.

Answer: 4. Insect pests.

Question 104. Penicillin kills bacteria by :

  1. Suppression of cell wall synthesis
  2. Lysis of protoplasm
  3. Interfering with RNA synthesis
  4. Inhibiting dna synthesis.

Answer: 1. Suppression of cell wall synthesis

Question 105. Which of the following antibiotics is more a research tool rather than used for clinical purposes :

  1. Penicillin
  2. Terramycin
  3. Actinomycin-d
  4. None of these.

Answer: 3. Actinomycin-d

Biological Classification MCQ For NEET Question 106. Doxycycline treatment cures :

  1. Aids caused by virus
  2. Polio caused by virus
  3. Measles caused by virus
  4. Male sterility caused by mycoplasma.

Answer: 4. Male sterility caused by mycoplasma.

Question 107. Wall is not pirseni in :

  1. Mycoplasma
  2. Aciiiiomycclcs
  3. Vituses
  4. L.-Loim baelcria.

Answer: 1. Mycoplasma

Question 108. Penicillin and vancomycin do not ail late mycoplasma because :

  1. Prokaryotic and unicellular
  2. Eukaryotic and unicellular
  3. There is no nucleus
  4. There is no cell wall.

Answer: 4. There is no cell wall.

Question 109. Llypersaline and hyperthermal aquatic environments are inhabited mostly by :

  1. Eubacteria
  2. Micro fungi
  3. Cyanobacteria
  4. Archacbactcria.

Answer: 4. Archacbactcria.

Question 110. Peritrichous bacteria have :

  1. Flagella all over the body
  2. Tuft of flagella at one end
  3. Tuft of flagella at both ends
  4. Single flagellum at one end.

Answer: 1. Flagella all over the body

Question 111. A bacterial cell contains :

  1. Mesosomes, Golgi bodies, and nucleoid
  2. Mesosomes and Golgi bodies
  3. Mesosomes and nucleoid
  4. Golgi bodies and nucleoids.

Answer: 3. Mesosomes and nucleoid

Biological Classification MCQ For NEET Question 112. To develop flavor and taste in tobacco, leaves are processed with bacterium:

  1. Mycococcus candisans
  2. Megatherium micrococcus
  3. Aerobacter
  4. None of the above.

Answer: 2. Megathenium micrococcus

Question 113. Magnesium ribonuclease is present in :

  1. Gram (+) ve bacteria
  2. Gram (-) ve bacteria
  3. Both 1 and 2
  4. None of the above.

Answer: 1. Gram (+) ve bacteria

Question 114. The bacterial decomposition of nitrogenous organic compounds in the absence of abundant oxygen usually results in the formation of substances of offensive odor, chiefly sulfur compounds. Such anaerobic decomposition is called :

  1. Nitrification
  2. Denitrification
  3. Putrefaction
  4. N2 fixation.

Answer: 3. Putrefaction

Question 115. Bacteria were called ‘tiny animalcules’ by Leeuwenhoek who discovered them from tartar scrapped from teeth. Who coined the term bacteria:

  1. Ehrenberg
  2. Nageli
  3. Pasteur
  4. Koch.

Answer: 1. Ehrenberg

Question 116. Name the bacterium that gets its energy from fermentation and if oxygen is given, it dies:

  1. Obligate aerobe
  2. Facultative anaerobe
  3. Obligate anaerobe
  4. Aerobe.

Answer: 3. Obligate anaerobe

Question 117. During gram’s staining :

  1. Gram (+) ve bacteria take crystal violet stain
  2. All bacteria take crystal violet stain
  3. Only gram (-) ve bacteria take crystal violet stain
  4. Gram (-) ve bacteria lose this stain after alcohol treatment.

Answer: 4. Gram (-) ve bacteria lose this stain after alcohol treatment.

Question 118. Compared to gram(-) bacteria. Gram (+) vc bacteria:

  1. Are more resistant to antibiotics
  2. Have more complex cell walls
  3. Have less muicopcptidc
  4. Retain crystal violet dye even after alcohol treatment.

Answer: 4. Have more complex cell walls

Question 119. Cyanobacteria living inside (the protozoans are called:

  1. Cyanellc
  2. Blue-green algae
  3. Mvxophyceac
  4. Euglenoids.

Answer: 1. Cyanellc

Question 120. The true diploid condition in bacteria is not obtained due to the reasons:

  1. Only a part of a chromosome is transferred to the female cell
  2. Introduced dna merely adds to the original dna of the female cell
  3. Introduced dna replaces a part of the original dna of the female cell
  4. All of the above.

Answer: 1. Only a part of a chromosome is transferred to the female cell

Most Important MCQs on Monera Question 121. Water bloom occurs mainly due to the presence of:

  1. Cyanobacteria
  2. Insects
  3. Bacteria
  4. Red algae.

Answer: 1. Cyanobacteria

Question 122. Which one of the following is a false statement regarding plasmids:

  1. Plasmids are extrachromosomal materials found in bacterial cells
  2. Most plasmids can be transmitted from cell to cell by infection without bringing about the death of host cells
  3. Plasmids can be integrated into the host chromosomes
  4. Plasmids are integrated but inert parts of the genetic element.

Answer: 2. Most plasmids can be transmitted from cell to cell by infection without bringing about the death of host cells

Question 123. Which of the following is a bacterial disease?

  1. Club rot disease of cotton
  2. Angular leaf spot disease of cotton
  3. Leaf spot disease of turmeric
  4. Wilt disease of tomato.

Answer: 2. Angular leaf spot disease of cotton

Question 124. Which of the following causes crown gall in plants :

  1. Erwinia carotovora
  2. Pseudomonas solanacearum
  3. Agrobacterium tumefaciens
  4. Xanthomonas malvacearum.

Answer: 3. Pseudomonas solanacearum

Question 125. Match the terms in column I with those in column d:

Kingdom Monera Question 125 Match the terms

  1. 1-C,2-B,3-A,4-D
  2. 1-C,2-A,3-B,4-D
  3. 1-C,2-D,3-A,4-B
  4. 1-C,2-A,3-D,4-B

Answer: 4. 1-C,2-A,3-D,4-B

Question 126. Which of the following pairs is/arc correctly matched:

  1. E.coli— circular dna
  2. Tobacco mosaic virus—single-stranded RNA
  3. Rcovirus—double-stranded RNA

Select the correct answer using the codes given below Codes:

  1. A alone
  2. A, b and c
  3. A and c
  4. B and c.

Answer: 2. A, b and c

Most Important MCQs on Monera Question 127. Match list 1 wish list 2 and select the correct answer using the codes given below the lists-

Kingdom Monera Question 127 Match the terms

  1. 1-A,2-B,3-C,4-D
  2. 1-D,2-A,3-B,4-C
  3. 1-C,2-B,3-A,4-D
  4. 1-B,2-C,3-D,4-A

Answer: 2. 1-D,2-A,3-B,4-C

Question 128. Wine turns sour because of :

  1. By fermentation of sugar by lactobacillus
  2. By fermentation of sugar by Aspergillus
  3. By fermentation of sugar by saccharomyces cerevisiae
  4. Is a two-step process, first involving fermentation of sugar by yeast and second involving fermentation of ethyl alcohol by acetic acid bacteria.

Answer: 4. Is a two-step process, first involving fermentation of sugar by yeast and second involving fermentation of ethyl alcohol by acetic acid bacteria.

Question 129. Clear areas of agar plates containing phage particles as well as bacteria are called:

  1. Bacteriophage
  2. Transparencies
  3. Plaques
  4. Holes.

Answer: 3. Plaques

Question 130. Bacteria do not have a major role in the production of the following

  1. Coffee
  2. B-complex
  3. Cheese
  4. Bread.

Answer: 4. Bread.

Question 131. Episome or f factor is the extrachromosomal genetic material of bacteria, useful in:

  1. Control of essential characters
  2. Genetic recombination
  3. Formation of endospores
  4. Nitrogen fixation.

Answer: 2. Genetic recombination

Question 132. A scientist wants to try to grow a culture of an animal virus. Which of the following would most likely be a suitable cultural medium?

  1. Boiled and cooled water with minerals and vitamins added.
  2. Sterile jelly made with malt and agar.
  3. An infertile egg.
  4. Living chick embryos.

Answer: 4. A living chick embryo.

Biotechnology And Its Applications For NEET

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Biotechnology And Its Applications For NEET

Biotechnology can be defined as the use of microorganisms, plain and animal cells for commercial-scale production of biopharmaceuticals and for human welfare.

The Applications Of Biotechnology Include:

  1. Therapeutics
  2. Diagnostics
  3. Genetically modified crops for agriculture
  4. Processed food
  5. Bioremediation
  6. Energy production and
  7. Waste treatment

The Three Critical Research Areas Of Biotechnology Are:

  1. Providing the best catalyst in the form of an improved organism, usually in the form of a microbe or pure enzyme.
  2. Creating optimal conditions through engineering for a catalyst to function.
  3. Downstream processing technologies to purify the protein/organic compound for marketing.

Read and Learn More NEET Biology Notes

Applications Of Biotechnology In Agriculture For NEET

The Three Options For Increased Food Production Are:

  • Agrochemical-based agriculture.
  • Organic agriculture and
  • Genetically engineered crop-based agriculture.

The Green Revolution succeeded in increasing the yield of crops mainly due to

  • Use of improved varieties of crops and
  • Use of agrochemicals (fertilizers and pesticides).
  • Further increases in the yield with the existing varieties of crops are not possible using conventional methods of breeding.
  • Agrochemicals cause soil and water pollution and are too expensive for farmers.

Biotechnology And Its Applications NEET Notes

Genetically Modified Crops:

A transgenic crop incorporates and expresses a transgene. A prevalent designation for transgenic crops is genetically modified crops, or GM crops.

The methodologies employed in the cultivation of transgenic crops provide two distinct advantages:

  1. Any gene, whether derived from an organism or manufactured chemically, can be utilized for transfer
  2. The alteration in genotype can be meticulously regulated since only the transgenic is incorporated into the crop genome.

Genetically Modified Crops Contrasting Breeding Activities:

  • Only genes existing in specific species can undergo hybridization within those species.
  • Alterations arise in all qualities for which the parental organisms utilized in hybridization exhibit differences.
  • Upon the introduction of a transgene into an organism’s genome, it may accomplish one of the following outcomes:
  • Generates a protein that is the subject of our interest.
  • Generates a protein that independently manifests the desired trait.
  • Alters an established metabolic pathway to provide a novel end product.
  • Inhibits the expression of a pre-existing native gene.

Hirudin is a protein that inhibits coagulation. The gene that encodes hirudin was produced chemically. The gene was subsequently introduced into Brassica napus, resulting in the accumulation of hirudin in the seeds. Hirudin is refined and utilized as a pharmaceutical agent. The transgene product is the primary focus of interest.

The ‘Flavr Savr’ tomato variety exemplifies the suppression of a native tomato gene’s expression. The expression of a native gene can be inhibited by many techniques.

The enzyme polygalacturonase facilitates fruit softening by degrading pectin.

  • The transgenic tomato cultivar ‘Flavr Savr’ exhibited a cessation of polygalacturonase production.
  • Consequently, the fruits of this tomato variety maintain freshness and preserve their flavor significantly longer than those of other tomato types.
  • Furthermore, the fruits exhibit an enhanced flavor and elevated total soluble solids, which serve as an unforeseen advantage.

The final two elements are under investigation through various tests prior to arriving at a definitive conclusion.

Genetically Modified Food:

The food prepared from the produce of genetically modified (= transgenic) crops is called genetically modified food, or in short, GM food. GM food differs from the food prepared from the produce of conventionally developed varieties mainly in the following aspects.

  • Genetically modified food contains the protein produced by the transgene in question, for example, Cry protein in the case of insect resistance varieties.
  • Genetically modified food contains the enzyme produced by the antibiotic resistance gene that was used during gene transfer by genetic engineering.
  • Genetically modified food contains the antibiotic resistance gene itself.
  • Genetically modified food t has been argued that the above features of GM foods could lead to the following problems when they are consumed. Firstly, the transgene product may cause toxicity and/or produce allergies. Secondly, the enzyme produced by the antibiotic resistance gene could cause allergies, since it is a foreign protein.
  • Finally, the bacteria in the alimentary canal of humans could take up the antibiotic resistance gene in GM food. These bacteria would then become resistant to the concerned antibiotic. As a result, these bacteria could become difficult to manage.

The scientists involved in the production of transgenic crops are addressing to these concerns. Efforts are being made to use other genes in place of antibiotic resistance genes. The toxic and allergenic actions of the transgene product can be adequately examined by detailed assays using suitable animal models.

NEET Biotechnology And Its Application Notes

Biotechnology For NEET GM Products Benefits And Controversies

GM Products Benefits And Controversies Benefits

  1. Crops
    1. Enhance taste and quality
    2. Reduced maturation time
    3. Increased nutrients, yields, and stress tolerance
    4. Improved resistance to disease, pests, and herbicides
    5. New products and growing techniques.
  2. Animals
    1. Increased resistance, productivity, hardiness, and feed efficiency
    2. Better yields of meat, eggs, and milk
    3. Improved animal health and diagnostic methods.
  3. Environment
    1. “Friendly” bioherbicides and bioinsecticides
    2. Conservation of soil, water, and energy
    3. Bioprocessing for forestry products
    4. Better natural waste management
    5. More efficient processing.
  4. Society: Increased food security for growing populations.

GM Products Benefits And Controversies Controversies Safety:

  1. Potential human health impact
  2. Allergens, transfer of antibiotic resistance markers, unknown effects
  3. Potential environmental impact
  4. Unintended transfer of transgenes through cross-pollination, unknown effects on other organisms (for example, soil microbes), and
  5. Loss of flora and fauna biodiversity

Biotechnology And Its Applications NEET Important Questions

Biotechnology For NEET Applications Of Genetically Engineered Microbes

Nif genes, Found in Rliizobiuin leguminosarum may be transferred to major food crops to increase food production without using expensive fertilizers

Introduction Of Gene For Coding: Vitamins, antibiotics, and hormones from higher animals to bacteria—thus Bacteria will act as living factories.

Biotechnology And Its Applications Applications Of Genetically Engineered Microbes

Production Of Pest Resistant Plants Bt Cotton.

The soil bacteria Bacillus thuringiensis synthesizes crystal proteins known as Cry proteins, which are lethal to the larvae of insects such as tobacco budworms, armyworms, beetles, and mosquitoes.

  • The Cry proteins are present as inactive protoxins and are transformed into active toxins upon ingestion by the insect, as the alkaline pH of the stomach solubilizes the crystals.
  • The active toxin adheres to the epithelial cell surface of the midgut and forms pores.
  • This induces cellular swelling and lysis, resulting in the insect’s (larva’s) demise.
  • The cry genes that encode this protein are extracted from the bacterium and integrated into several crop plants like as cotton, tomato, corn, rice, and soybean.
  • The proteins expressed by the specified cry genes regulate the corresponding pest resistance.
  • Cry 1 Ac and Cry 2 Ab regulate cotton bollworm populations.
  • Cry 1 Ab regulates the borer.
  • Cry 3 Ab targets the Colorado potato beetle, while Cry 3 Bb targets the corn rootworm.

Protection Against Nematodes

  • A nematode Meloidogyne incognita infects tobacco plants and reduces their yield.
  • The specific genes (in the form of cDNA) from the parasite are introduced into the plant using Agrobacterium as the vector.
  • The genes are introduced in such a way that both sense/coding RNA and antisense RNA (complementary to the sense/coding RNA) are produced,
  • Since these two RNAs are complementary, they form a double-stranded RNA (ds RNA).
  • This neutralizes the specific RNA of the nematode, by a process called RNA- interference.

As a result, the parasite cannot live in the transgenic host and the transgenic plant is protected from the pest.

  • Tomato resistant to Homeworm larvae.
  • Similarly Tobacco, Populus, etc. with the help of Agrobacterium tumefaciens
  • Transgenic potato and tobacco plants that produce human serum albumin (USA)
  • Transgenic potato plants, with increased levels of cyclodextrins.
  • Transgenic tobacco plants with increased levels of mannitol
  • Transgenic plant for hybrid seed production.

Biotechnology And Its Applications Transgenic Plants And Appications

Genetically Modified Food:

A tomato called Flavr Savr has been created to have a better flavourful shelf-life. It is due to delayed ripening.

This has been achieved in reducing the contents of cells with a degrading enzyme called as polygalacturonase which leads to tomato fruit ripening. Another example of transgenic modified food is transgenic rice with higher vitamin A contents.

Transgenic Animals:

We can produce new animals and human beings, having traits tailored according to our own will.

Biotechnology And Its Applications Transgenic Animlas And Applications

Biotechnological Applications For NEET In Medicine

Therapeutic Agents: Proteins with potential as pharmaceutical agents are produced by using genetically engineered organisms. Enzymes have also been used for this purpose, for example, DNase 1 and alginate lyase have been used in aerosols. Some known examples are given below:

  1. Human growth hormone obtained from E. coil is used for the treatment of dwarfs.
  2. Chorionic gi nadotropin hormone produced by genetic engineering is used for the treatment of infertility.
  3. Interferons produced by E. coli are commercially used for the treatment of viral infections and cancer. Interferons were first obtained through DNA recombinant technique by Charles Weisman in 1980. He inserted the gene for interferon production in E. coli.
  4. Interleukins produced by E. coli are used to stimulate the immunity system.
  5. Tissue Plasminogen Activator (TPA) – an enzyme is used for dissolving blood clots after a heart attack and stroke.
  6. Antihemophilic human factor 8 is used by people with hemophilia to prevent and control bleeding or to prepare them for surgery.
  7. Platelet-derived growth factor produced by recombinant DNA technology is useful for stimulating wound healing.
  8. Penicillin G acylase is also produced by genetic engineering. This enzyme is used for converting penicillin into 6- 6-amino penicillin acid for the formation of new antibiotics.

Biotechnology And Its Applications NEET Previous Year Questions

Molecular Diagnosis: Recombinant DNA molecules and techniques like PCR (Polymerase Chain Reaction; are used for early diagnosis of disorders.

  • Cloned genes when expressed to produce recombinant proteins, help in developing sensitive diagnostic techniques like ELISA.
  • The cloned genes are also used as ’probes’ to detect the presence of complementary DNA strands.
  • A probe is a piece of single-stranded DNA that is tagged with a radioactive molecule and it is used to find its complementary DNA by hybridisation.
  • It is followed by the detection of radioactivity by autoradiography.
  • The presence of a normal or mutant gene can be detected using such a method.
  • PCR is used to detect HTV and to detect mutations in genes.

Biotechnology For NEET Genetically Engineered Insulin (Humulin)

Human insulin consists of so short polypeptide chains: chain A and chain B linked by disulfide bridges.

  • Insulin is secreted as prohormone which has to be processed before it becomes a mature and functional hormone.
  • The prohormone contains another polypeptide called C-peptide, which is removed during maturation.

Gene For Coding Insulin: From humans to bacteria is transferred and the insulin produced is called Humulin. In 1983. American Company Eli Lily produced genetically engineered Insulin called Humulin with the help of E. coli—Plasmid clone.

  • In 1983, Eli Lilly, an American company, prepared two DNA sequences coding for chains A and B of human insulin and introduced them into the plasmids of Escherichia coli to produce insulin.
  • The two chains produced were extracted and combined by creating disulfide bridges.

Biotechnology For NEET Gene For Preparing Interferon

Charles Weismann produced interferon through recombinants of E. coli. Production of transgenic plants for preparing recombinant products.

Many viral, bacterial, and protozoan vaccines are being synthesized through the technique of genetic engineering. These synthetically produced vaccines are the latest ones used in immunization. The gene coding for antigen protein is isolated from the pathogen and is cloned in bacterial host cells.

The social, economic, and environmental implications of genetic engineering techniques.

  1. Generally prepared human insulin and edible vaccines will be readily available and also will be economical.
  2. Transgenic crop plants for human consumption may cause concerns about safety due to unwanted properties they may have.
    • Hence the Indian Government has set up organizations that are authorized to make decisions regarding the validity of genetic modifications and the safety of introducing genetically modified organisms for public sendees.
    • One such organization is the Genetic Engineering Approval Committee (GEAC).
  3. Some people believe that transgenic plants and animals can solve many human problems, especially of hunger and disease.

Biotechnology For NEET cDNA Library

The copy of DNA formed on mRNA is called cDNA. 1,000 – 30,000 types of various mRNA sequences can be obtained from a typical eukaryotic cell.

  • cDNA library and cDNA clone bank are the populations of such viruses where each virus has at least one cDNA inserted plasmid is present.
  • In a complete viral population, each member has from outside DNA sequence.
  • It is easy to make a clone bank of those viruses that have DNA as genetic material, for example, the Influenza virus and Reovirus, etc.
  • Prokaryotic gene has no introns, so cDNA is the continuous copy of mRNA while in Eukaryotes introns break the DNA molecules in small segments called exons.

Single Cell Proteins (SCP). Cells from different kinds of organisms such as bacteria, filamentous fungi, yeast, and algae are treated in different ways so that they are used as food or feed, and are called single cell protein.

The biomass is obtained from both mono and multicellular micro-organisms. The common substrate used for preparing such food containing SCP ranges from air, whey, sawdust, and paddy straw. SCA provides a valuable protein supplement in the human diet.

Advantages Of Introducing Transgene

  1. Formation of a desired protein.
  2. Produces a protein that on its own produces the desired phenotype.
  3. Modifies an existing biosynthetic pathway so that a new end product is obtained.
  4. Prevents the expression of an existing native gene.

For example, Hirudin is a protein that prevents blood clotting. The gene encoding for hirudin was chemically synthesized’’ This gene was then transferred into Brassica napus. where hirudin accumulates in seeds. The hirudin is purified and used as medicine. In this case, the transgene product itself is the product of interest.

Biofertilizers: These are organisms that can bring about soil nutrient (like nitrogen or phosphorus) enrichment. The main sources of biolertilizers are bacteria, cyanobacteria, and fungi. Rhizobin from root nodules in legumes and cyanobacteria from symbiotic association with the form Azolla. The fungus and plant root association is termed mycorrhiza.

  • They Are The Following Advantages Thus Preferred To Chemical Fertilizers:
    1. They are safe and moreover do not pollute the atmosphere.
    2. The surface runoff does not pollute water.
    3. They do not disturb the naturally occurring food chains.
    4. They are of low cost as compared to chemical fertilizers and pesticides.
    5. They do not cause any danger to the natural resources.
    6. Pesticides are poisons and non-specific in their target. They also kill useful predators and upset the natural balance.

Biopesticide involves the biological control of weeds, insects, and pathogens by some living organisms. It involves the use of insects feeding on a specific weed or the use of certain microorganisms viruses, bacteria, fungi, protozoa, or mites which will cause disease in weeds.

  • The first bioherbicide was developed in 1961 and it was a mycoherbicide derived from the fungus Phytophthora palmivora which controls the growth of milkweed vines in citrus orchards.
  • Another fine example of biological control of weeds is the control of overgrowth of cacti by the introduction of a cochineal insect (Cactoblastis cactorum) in India and Australia.

Key Concepts Of Biotechnology And Its Applications For NEET

A few Examples Of Biopesticides Are: Biochemical active ingredients

  1. Plant Volatile And Floral Attractants
    1. Lemon grass oil
    2. Eucalyptus oil
    3. Mustard oil (Allyl isothiocyanate)
    4. Geranium oil
    5. Citronella oil
  2. Natural Insect Growth Regulators
    1. Dihydroazadirachtin
    2. Azadirachtin.
    3. Biological products Transgenic animals that produce useful biological products can be created by the introduction of the portion of DNA that codes for a particular product such as human proteins (α-antitrypsin) used to treat emphysema.
      • Similar attempts are being made for the treatment of phenylketonuria and cystic fibrosis. In 1997, the first transgenic cow, Rosie, produced human protein-enriched milk (2.4 g/L). The milk contained human alpha-lactalbumin and was nutritionally a more balanced product for human babies.
    4. Vaccine safety Transgenic mice are being developed for use in testing the safety of vaccines before they are used on humans. Transgenic mice are being used to test the safety of the polio vaccine.
    5. Chemical safety testing Transgenic animals are made that carry genes that make them more sensitive to toxic substances than non-transgenic animals. They are then exposed to the toxic substances and the effects studied. Toxicity testing in such animals will allow us to obtain results in less time.

Biopesticide Ethical Issues

  • The manipulation of living organisms by the human race cannot go on any further, without regulation.
  • Some ethical standards are required to evaluate the morality of all human activities that might help or harm living organisms.
  • Going beyond the morality of such issues, the biological significance of such things is also important. Genetic modification of organisms can have unpredictable results when such organisms are introduced into the ecosystem.
  • Therefore, the Indian Government has set up organizations such as GEAC (Genetic Engineering Approval Committee), which will make decisions regarding the validity of GM research and the safety of introducing GM organisms for public services.

The major bioethical concerns connected with exploits of biotechnology are

  1. The use of animals in biotechnology causes great suffering to them.
  2. When animals are used for the production of pharmaceutical proteins, they are virtually reduced to the status of a factory.
  3. The introduction of a transgene from one species into another species violates the integrity of the species.
  4. The transfer of human genes into animals (and vice-versa) dilutes the concept of humanness.
  5. Biotechnology is disrespectful to living beings and only exploits them for the benefit of human beings.
  6. Biotechnology may pose unforeseen risks to the environment, including risks to biodiversity.

Biological Resources Or Bioresources:

Biological Resources Or Bioresources include all those organisms that can be used to derive commercial benefits. Traditional knowledge related to bioresources is the knowledge developed by various communities over long periods of history, regarding the utilization of bioresources, for example, the use of herbs, etc. as drugs.

Often, this traditional knowledge can be exploited to develop modern commercial processes. The traditional knowledge suggests the direction to be followed and saves considerable time, effort, and expenditure for their commercialization. Institutions and companies of industrialized nations are collecting and exploiting the bioresources, as follows.

  1. They are collecting and patenting the genetic resources themselves. For example, a patent granted in the U.S.A. covers the entire ‘basmati’ rice germplasm indigenous to our country.
  2. The bioresources are being analyzed for the identification of valuable biomolecules. A biomolecule is a compound produced by a living organism. The biomolecules are then patented and used for commercial activities.
  3. Useful genes are isolated from the bioresources and patented. These genes are then used to generate commercial products.
  4. The traditional knowledge related to bioresources is utilized to achieve the above objectives. In some cases, the traditional knowledge itself may be the subject of a patent.

A west African plant, Pentadiplcmdra brazzeana produces a protein called brazzein, which is approximately 2,000 times as sweet as sugar. In addition, brazzein is a low-calorie sweetener. Local people have known and used the super-sweet berries of this plant for centuries.

  • However, the protein brazzein was patented in the U.S.A. Subsequently, the gene encoding brazzein was also isolated, sequenced, and patented in the U.S.A. It is proposed to transfer the brazzein gene into maize and express it in maize kernels.
  • These kernels with then be used for the extraction of brazzein. This development could have serious implications for countries exporting large quantities of sugar.

Biopatent:

A patent is a right granted by a Government to an inventor to prevent others from making commercial use of such an invention. At present patents are granted for biological entities and the various products obtained from these organisms, termed as biopatent. Biopatents are being granted for the following

  1. Strains of micro-organisms
  2. Cell lines
  3. Genetically modified strains of living organisms
  4. DNA sequences
  5. The proteins prepared by DNA sequences
  6. Biotechnological process
  7. Production process
  8. Products
  9. Product application.

Biopiracy:

Exploitation of patent biological resources without proper permission is called biopiracy. The collection of such material without a benefit-sharing agreement is likely to find its way into the list of criminal violations in many countries.

  • For thousands of years, neem has been used in India for killing pests and as medicine. One of the American companies patented neem. As a result, anybody using neem will have to pay for it. This was called as legalized theft. Biopiracy permits the piracy of gene resources and knowledge from non-western countries. Such piracy was claimed by them as an invention.
  • Many biotechnology patents are very broad in their coverage. For example, one patent covers ‘all transgenic plants of Brassica family’. Such broad patents are considered morally unacceptable and fundamentally inequitable since these would enable financially powerful corporations to acquire monopoly control over biotechnological processes.
  • They may, in the end, even come to control the direction of agricultural research, including plant breeding. Such a position would pose a threat to the global food security.
  • Any organizations and multinational companies exploit and/or patent biological resources or bioresources of other nations without proper authorization from the countries concerned; this is known as biopiracy.
  • The industrialized nations are rich in technology and financial resources but poor in biodiversity and traditional knowledge related to the utilization of bioresources. In contrast, developing nations ar poor in technology and financial resources, but are rich in biodiversity and traditional knowledge related to bioresources

Biowar:

The use of bioweapons originated in the 5th century. It is the use of biological weapons against humans and their crops and animals. A bioweapon is a device that carries and delivers pathological biological agents or toxins to a target. Recently Anthrax bacterium was sent by post after the attack. It causes anthracis.

Biotechnology Applications NEET Important Questions With Answers

Misconceptions About Biological Weapons

  1. Technically difficult.
  2. Will not be used because use is morally repugnant.
  3. Rarely used, no chance of use of biological weapons in the near future.

Misconceptions About Biological Weapons Realities

  1. Biological agents for biological warfare are not costly and can be produced with ease.
  2. Detection or interdiction is almost impossible.
  3. Use is likely to increase.
  4. More dangerous than conventional weapons.

Misconceptions About Biological Weapons Real Threat

  1. It is considered that by 1995, more than 18 countries had biological weapons.
  2. Salmonella was used to contaminate salad bars in Oregan restaurants by members of a cult in 1984.
  3. Two members of a Minnesota militia group were convicted for having ricin in 1995.
  4. A lab. technician in Ohio placed orders for 3vials of Y. pestis by mail in 1995.

Biotechnology And Its Applications Meaning Of Biowar And Its tools

Potential Biological Weapon Agents. Biological Weapon agents can cause the following diseases

  1. Anthrax
  2. Smallpox (variala)
  3. Botulism toxins
  4. Plague
  5. Q. (fever, chills, fatigue, etc.)
  6. Tularemia (it can occur in humans in two forms; ulceroglandular and typhoidal).
  7. Viral Encephalitis,
  8. Viral hemorrhagic fevers.

Characteristics Of Biological Weapons That Make Them Attractive To Countries And Terrorists,

  1. Cost efficiency. Biological weapons are low-cost weapons.
  2. A large number of casualties. They cause far more casualties than chemical or conventional weapons.
  3. Biological weapon agents are invisible, odorless, and tasteless once released.

Defence Against Biological Weapons

  1. Respirator or gas mask;
  2. Safer shelter;
  3. Decontamination;
  4. Vaccination
  5. Antibiotics;
  6. Detection mechanism.

Bioethics:

Bioethics are a framework of principles utilized to govern our actions concerning biological endeavors.

The principal bioethical issues are as follows:

  1. The incorporation of transgenes from one species into another undermines species integrity.
  2. The transfer of human genes to other animals and vice versa is unethical.
  3. Creation of a clone.
  4. May pose a threat to biodiversity.
  5. The suffering of animals utilized in biotechnology will escalate.

Fermentation:

The anaerobic oxidation of food in the presence of micro-organisms which results in the production of alcohol and waste gas CO2.

Immobilization Of Enzymes:

It is the process of fixing an enzyme or enclosing it in solid support so as to protect it from deactivation and attack of proteases, maintain enzyme purity, ability to recover it after reaction and perform the continuous reaction.

The methods which include covalently attaching the enzyme to a solid support, trapping it in a gel, crosslinking the enzyme molecules to one another, and encapsulating them in small artificial cells is called immobilization of enzymes.

Biotechnology And Its Applications Applications Of Biotechnology Flowchart

Biotechnology And Its Applications MCQs For NEET

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NEET Biology Biotechnology And Its Applications Multiple Choice Questions

Question 1. How many recombinant therapeutics have been approved for human use the world over?

  1. 12
  2. 30
  3. 20
  4. 18

Answer: 2. 30

Question 2. Which of the following techniques serve the purpose of early diagnosis?

  1. Recombinant DNA technology
  2. PCR
  3. ELISA
  1. 1 only
  2. 1 and 3 only
  3. 1 and 2 only
  4. 2 and 3.

Answer: 4. 2 and 3

Question 3. Which of the following techniques is based upon the principle of antigen-antibody interaction?

  1. PCR
  2. ELISA
  3. Recombinant DNA technology
  4. RNA interference.

Answer: 2. ELISA

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 4. Which of the following transgenic protein products has been used to treat emphysema?

  1. α-1-antitrypsin
  2. a-Lactalbuniin
  3. Cry protein
  4. C-peptide.

Answer: 1. α-1-antitrypsin

Biotechnology And Its Applications MCQs For NEET

Biotechnology and its Applications Zoology NEET Question 5. The Bt toxin gene has been cloned from the bacteria and expressed in plants to provide resistance to insects without the need for insecticides. Select these resistant plants from the given list.

  1. Cotton
  2. Corn
  3. Rice
  4. Tomato
  5. Potato
  6. Soyabean
  1. 1, 2, 3 and 4
  2. 2, 3, 4 and 5
  3. 1, 2, 5 and 6
  4. All of these

Answer: 4. All of these

Question 6. Which of the following is/are correct about the process of RNA interference?

  1. This is used to prevent the infestation of protozoans.
  2. It takes place in some eukaryotic and all prokaryotic organisms as a method of cellular defense.
  3. The method involves silencing a specific mRNA due to a complementary dsRNA molecule.
  4. It is a novel strategy to produce pest-resistant plants
  1. 3 and 4
  2. 2, 3 and 4
  3. 1 and 3
  4. 3 only

Answer: 1. 3 and 4

Question 7. Which ingredient was present in high concentrations in genetically modified (GM) rice as compared to the usual rice?

  1. Protein
  2. Carbohydrates
  3. Na+ ions
  4. Vitamin A.

Answer: 4. Vitamin A.

Question 8. Animals that have had their DNA manipulated to possess and express an extra gene are known as:

  1. Foreign animals
  2. Superior animals
  3. Transgenic animals
  4. Intergenic animals.

Answer: 3. Transgenic animals

Biotechnology and its Applications Zoology NEET Question 9. About 95 percent of all existing transgenic animals are

  1. Rabbits
  2. Pigs
  3. Crovs
  4. Mice

Answer: 4. Mice

Question 10. Today, transgenic models exist for many human diseases which include:

  1. Cancer
  2. Cystic fibrosis
  3. Rheumatoid arthritis
  4. Alzheimer’s disease.
  1. 1 and 3 only
  2. 2 and 3 only
  3. 1, 2 and 3 only
  4. 1, 2, 3 and 4.

Answer: 4. 1, 2, 3 and 4.

Question 11. Which of the following is not a true statement with respect to Bt cotton?

  1. Bt toxin is produced by a bacterium Hticillus tliuringH’nsix
  2. It is an example of bio-pesticide
  3. Bt toxin gene has been cloned in plants to provide resistance to insects
  4. Bt cotton could decrease the amount of pesticide used.

Answer: 3. Bt toxin gene has been cloned in plants to provide resistance to insects

Question 12. Match the following genes in Column-A with the insect that can be protected from with their coded protein in Column-B.

Biotechnology And Its Applications Match The Genes With Insect That Can Be Protected From With Their Coded Protein

  1. 1(A), 2(C), 3(B)
  2. 1(B), 2(A), 3(C)
  3. 1(A), 2(B), 3(C)
  4. 1(B), 2(C), 3(A).

Answer: 1. 1(A), 2(C), 3(B)

NEET Questions Biotechnology And Its Application Question 13. Which protein would you like to be produced by genetic engineering as a cure for diseases like emphysema?

  1. α-1-antitrypsin
  2. Trypsin
  3. Chymotrypsin
  4. All of the above are required.

Answer: 1. α-1-antitrypsin

Question 14. ‘Rosie’ a transgenic cow is known to produce a type of milk that has all the following characteristics except:

  1. Proteimeontent of 2.4 gm/litre
  2. Has human α-lactalbumin
  3. More balanced diet than normal cow milk for babies
  4. Was produced for the first time in the year 2001.

Answer: 4. Was produced for the first time in the year 2001.

Question 15. According to the latest estimates, how many documented varieties of Basmati rice are grown in India?

  1. 30
  2. 27
  3. 118
  4. 125.

Answer: 2. 27

Question 16. An anti-bacterial compound that prevents mastitis in cows is:

  1. α-1-antitrypsin
  2. Lysostaphin
  3. Lysozyme
  4. Alginate lyase.

Answer: 2. Lysostaphin

NEET Questions Biotechnology And Its Application Question 17. Choose the incorrect statement with respect to Bioweapons

  1. They are low-cost weapons
  2. They cause more casualties than conventional weapons
  3. They are extremely difficult to detect
  4. Bacterium E. coli created a later scare in 2001.

Answer: 4. Bacterium E. coli was created later in 2001

Question 18. A set of standards by which a community regulates its behavior and activities in relation to the biological world is termed as:

  1. Biopatent
  2. Biopiracy
  3. Patent
  4. Biocthic.

Answer: 4. Biocthic.

Question 19. Nexia biotechnologies spliced spider genes into the cells of lactating:

  1. Cow
  2. Sheep
  3. Goat
  4. None of these.

Answer: 3. Goat

Question 20. How many varieties of rice have been estimated to be present in India’?

  1. 2.000
  2. 20,000
  3. 200,000
  4. 2,000,000.

Answer: 3. 200,000

NEET Questions Biotechnology And Its Application Question 21. The use of bioresources by multinational companies and other organizations without proper authorization from the countries and people concerned without compensatory’ payment is called:

  1. Bioethics
  2. Biopiracy
  3. Bioterror
  4. Bioweapon.

Answer: 2. Biopiracy

Question 22. Amongst the following which characteristics is not applicable to Bt cotton?

  1. Bt is the abbreviated term for botulinum toxin
  2. Such cotton is resistant to armyworms and beetles
  3. The toxin is activated in the body of the insect
  4. The toxin is coded by a gene called ‘cry’.

Answer: 1. Bt is the abbreviated term for botulinum toxin

Question 23. Which biotechnology company is credited with the synthesis of genetically engineered human insulin for the first time?

  1. Celera genomics
  2. Cipla
  3. Eli Lily
  4. Ranbaxy.

Answer: 3. Eli Lily

NEET Questions Biotechnology And Its Application Question 24. Pick the odd one out

  1. DNA micro-injection
  2. RNA interference
  3. Retrovirus-mediated gene transfer
  4. Embryonic stem cell-mediated gene transfer.

Answer: 2. RNA interference

Question 25. In Xenotransplantation, a protein that causes graft rejection comes usually from transgenic

  1. Cow
  2. Mice
  3. Pig
  4. Sheep.

Answer: 3. Pig

Question 26. Transgenics have provided many pharmaceuticals in their milk, for the treatment of diseases. Which of the following has not been a successful story?

  1. Phenylketonuria
  2. SCID
  3. Emphysema (hereditary)
  4. CFTR.

Answer: 2. SCID

Question 27. Which is not true with respect to transgenic animals and their contribution to human welfare?

  1. Transgenic mice are being tested to ensure the safety of the polio vaccine
  2. Rosie’s milk contained the human gene insulin
  3. Transgenic cows produce milk with less lactose
  4. Transgenic sheep grow more wool.

Answer: 2. Rosie’s milk contained the human gene insulin

Question 28. The functional ADA cDNA can be introduced into the cells of the patient receiving gene therapy by using a vector constituted by

  1. E. coli
  2. Reovirus
  3. Retrovirus
  4. Agrobacterium.

Answer: 3. Retrovirus

Biotechnology and Its Applications Biology NEET Question 29. Which variety office was patented by a U.S. company even though the highest number of varieties of this rice is found in India?

  1. Sharbati Sonora
  2. Co-667
  3. Basmati
  4. Lerma Roja.

Answer: 3. Basmati

Question 30. Which step of Government of India has taken to cater to the requirement of patent terms and other emergency provisions in this regard?

  1. Biopiracy act
  2. Indian patents bill
  3. RTI act
  4. Negotiable Instruments Act.

Answer: 2. Indian patents bill

Question 31. What is another term used for GMO (Genetically Modified Organisms)?

  1. Cybrid organisms
  2. Geromorphic organisms
  3. Transgenic organisms
  4. Conjoint twins.

Answer: 3. Transgenic organisms

Question 32. Which one of the following can be used as a permanent cure for ADA deficiency?

  1. Bone marrow transplantation upon detection of disorder in adult
  2. Enzyme replacement therapy at any point in life
  3. Both 1 and 2
  4. Gene therapy at early embryonic stages.

Answer: 4. Gene therapy at early embryonic stages.

Biotechnology and Its Applications Biology NEET Question 33. Which of the following is a transgenic product useful for the treatment of Haemophilia?

  1. Factor 8
  2. Antithrombin 2
  3. α-1 -antitrypsin
  4. Lysostaphin.

Answer: 1. Factor 8

Question 34. Who is responsible for obtaining interferons through recombinant DNA technique?

  1. A.R. Bunting
  2. Eli Lily
  3. A. Tiselius.
  4. Charles Weissmann

Answer: 3. A. Tiselius

Question 35. Select the incorrect statement

  1. RNAi silencing takes place in all eukaryotic organisms as a method of cellular defense
  2. RNAi requires silencing of mRNA by binding of complementary ssDNA molecule
  3. Complementary nucleic acid could be from mobile genetic elements (transposons)
  4. Ti plasmid with nematode-specific genes have been used in RNAi.

Answer: 2. RNAi requires silencing of mRNA by binding of complementary ssDNA molecule

Biotechnology and It’s Applications Biology NEET Question 36. Identify the correct match for the given columns.

Biotechnology And Its Applications Identify And Match The Columns

  1. 1(D),2(C), 3(B), 4(A)
  2. 1(A),2(C), 3(D), 4(B)
  3. 1(D),2(B), 3(A), 4(C)
  4. 1(B),2(B), 3(D), 4(A)

Answer: 1. 1(D),2(C), 3(B), 4(A)

Question 37. Rules of conduct that may be used to regulate our activities in relation to the biological world is called

  1. Bioethics
  2. Biowar
  3. Biopatent
  4. Biopiracy.

Answer: 1. Bioethics

Question 38. Transgenic mice are being used to test the safety of:

  1. Polio vaccine
  2. BCG vaccine
  3. Antitrypsin
  4. Hepatitis B vaccine.

Answer: 1. Polio vaccine

Biotechnology and It’s Applications Biology NEET Question 39. Which genes encode the protein to control bollworm infection in cotton plants?

  1. Cry 2 Ab
  2. Cry 1 Ac
  3. Both (1) and (3)
  4. Ampr.

Answer: 3. Both (1) and (3)

Question 40. Which is Incorrect with respect to GM foods?

  1. It contains the protein produced by the transgene in question
  2. GM food contains antibiotic resistance gene itself
  3. The enzyme produced by antibiotic resistance gene will not cause allergies
  4. The bacteria is the gut of humans could be taken by antibiotic resistance genes.

Answer: 3. The enzyme produced by antibiotic resistance gene will not cause allergies

Question 41. Golden rice – a transgenic variety of rice is principally richer than normal rice in:

  1. Cry 1 Ab
  2. Hirudin
  3. TPA
  4. β-carotene.

Answer: 4. β-carotene.

Question 42. Southern blotting can’t be performed without

  1. Restriction endonucleases
  2. Agarose
  3. Monoclonal antibodies
  4. Both (1) and (2).

Answer: 4. Both (1) and (2).

Question 43. Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because:

  1. Bacteria are resistant to the toxin
  2. Toxin exists as a toxoid
  3. Toxins exist as protoxins
  4. Bacteria enclose toxins in a special sac.

Answer: 3. Toxins exist as protoxins

Question 44. What is the permanent curve of adenosine deaminase (ADA) deficiency in children?

  1. Bone marrow transplantation.
  2. Enzyme replacement therapy in which functional ADA is given to the patient by injection.
  3. Infusion of genetically engineered lymphocytes (in which functional ADA-cDNA is introduced) into the patient’s body.
  4. Introduction of gene isolated from bone marrow cells producing ADA, into cells at early embryonic stages.

Answer: 4. Introduction of gene isolated from bone marrow cells producing ADA, into cells at early embryonic stages.

Question 45. Which gene controls the transcription of chain A and chain B required for humulin synthesis in E. coli?

  1. β-lactamase
  2. β-galactosidase
  3. Poly galacturonic
  4. Chitinase.

Answer: 3. Poly galacturonic

Question 46. Transgenic Brassica napus has been used for the synthesis of

  1. Hirudin
  2. Heparin
  3. Polygalacturonase
  4. Cry protein.

Answer: 1. Hirudin

Question 47. Which of these participates in the manufacturing of dextrans:

  1. Mucor
  2. Lactobacillus
  3. Leuconostoc
  4. Pseudomonas.

Answer: 3. Leuconostoc

Question 48. Which of the following is used for the manufacture of cosmetics?

  1. Serotonin
  2. Cholesterol
  3. Shikonin
  4. Keratin.

Answer: 3. Shikonin

Question 49. The technique by which virus detection can be made both in plants and animals is known as:

  1. Enzyme-linked immunoabsorbent assay (ELISA)
  2. Electrophoresis
  3. Electron microscopy
  4. Immunofluorescence

Answer: 1. Enzyme-linked immunoabsorbent assay (ELISA)

Question 50. Streptokinase (TPA) helps in:

  1. Clearing blood clots
  2. Increasing plasma
  3. Dissolving tissues
  4. Increasing O.P. of the cell.

Answer: 1. Clearing blood clots

Question 51. The enzyme diastase was identified by:

  1. Payen and Persoz
  2. Waksman
  3. Christian Hansen
  4. Alexander Fleming.

Answer: 1. Payen and Persoz

Question 52. The immobilization of the enzyme is achieved by:

  1. Killing the cells without affecting enzymes
  2. Attaching the enzymes covalently to a solid support
  3. Entrapping the living cells in a gel
  4. All of these.

Answer: 4. All of these.

Question 53. Interferons are:

  1. Proteins released in minute quantities by animals or plant cells, on being infected with a virus
  2. Proteins synthesized in large quantities by cells actively engaged in synthesis
  3. Hormones released by cells in small quantities which influence some of the various physiological activities
  4. Defensive mechanism.

Answer: 1. Proteins released in minute quantities by animals or plant cells, on being infected with the virus

Question 54. Magic bullets are:

  1. Interferons
  2. Vaccines
  3. Monoclonal
  4. Antigen-antibody cells, antibodies

Answer: 3. Monoclonal

Question 55. Cheese contains:

  1. Proteins 20-35%, fats 20-3%
  2. Fats 20-35%, protein 20-30%
  3. Proteins double than fats
  4. Fats double proteins.

Answer: 1. Proteins 20-35%, fats 20-3%

Question 56. The hybridoma technique was developed by:

  1. Louis Pasteur
  2. Edward Jenner
  3. Georges Kohler
  4. Burnet. and Caser Milstein

Answer: 3. Georges Kohler

Question 57. Some of the steps involved in the production of humulin are given below. Choose the correct sequence.

  1. Synthesis of the gene (DNA) for human insulin artificially.
  2. Culturing recombinant E. coli in bioreactors.
  3. Purification of humulin.
  4. Insertion of human insulin gene into a plasmid.
  5. Introduction of recombinant plasmid into E. coli.
  6. Extraction of recombinant gene product from E. coli.
  1. 2, 1, 4, 3, 5, 6
  2. 1, 3, 5, 6, 2, 4
  3. 1, 4, 5, 2, 6, 3
  4. 3, 5, 2, 1, 6, 4

Answer: 3. 1, 4, 5, 2, 6, 3

NEET Biology Notes – Muscular System

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NEET Biology Muscular System

  • Movement is the displacement of body parts in relation to the body axis. It is a characteristic feature of living beings. Movements of, external and internal body parts occur.
  • Locomotion is the displacement of the body from one place to another place. Locomotion is the basic character of animals. Locomotion enables the animals to protect their bodies to search and procure food and water, to find their mate, escape from predators, shift to a favourable environment and find a suitable breeding ground.
  • Locomotion in acellular organisms takes place by three methods :
    1. Pseudopodial
    2. Ciliary
    3. Flagellar.
  • Pseudopodial locomotion takes place in Amoeba.
  • Ciliary locomotion takes place in Paramecium.
  • Flagellar locomotion takes place in Euglena.
  • Adult sponges are sedentary ties. fixed. Locomotion does not take place in them.
  • Their larvae move by cilia.
  • Locomotion in Hydra is muscular and also takes place by tentacles,
  • Bending and swaying
  • Looping
  • Somersaulting

Read and Learn More NEET Biology Notes

  • Gliding
  • Walking
  • Climbing
  • Surfacing
  • Floating
  • Swimming.
  • Locomotion in annelids takes place either by setae or parapodia. Locomotion by setae takes place in Pheretima and by parapodia in Nereis.
  • Locomotion in leeches takes place by muscular contraction and suckers.
  • Locomotion in arthropods takes place by jointed legs and wings.
  • Locomotion in molluscs takes place by foot
  • Locomotion in echinoderms takes place by tube feet
  • Locomotion in vertebrates takes place by fins and limbs.

Muscular System NEET Notes

NEET Biology Kingdom Protista Movements of External Body Parts

  1. Collection of information by the movement of pinnae, ocular orbits, neck, etc.
  2. Facial expressions and gestures
  3. Preservation of balance
  4. Movement of extremities and limbs for locomotion.
  5. Acquisition of sustenance, Consumption of nourishment.
  6. Nourishing offspring, Offensive and Defensive
  7. Respiration.

NEET Biology Kingdom Protista Movements of Internal Body Parts

  1. The heartbeat facilitates blood circulation.
  2. Contraction and relaxation of the diaphragm, ribs, and lungs facilitate gaseous exchange.
  3. Peristalsis is the pendular or segmental motion facilitating the transit of food through the alimentary canal.
  4. Peristalsis facilitates the movement of urine through the urinary system, while also generating sound.
  5. Movements of the genital tract and uterine wall during oviposition and parturition.
  6. Muscular activity in the movements of different body components.

NEET Biology Kingdom Protista Non Muscular Movements

  1. Such movements occur in protists and individual cells in higher organisms in the following ways:
  2. Pseudopodial/Amoeboid Movements. The movements occur using temporary protoplasmic outgrowths called pseudopodia.
  • Pseudopodia can develop in any direction due to the flow of protoplasm. Fresh pseudopodia develop as older ones are withdrawn.
  • Amoeba and iLs relatives creep using pseudopodia. The movements occur in macrophages and leucocytes. Because of them the cells can reach all body parts and engulf pathogens.
  1. Cyclosis/Cytoplasmic or Protoplasmic Streaming. It occurs only inside eukaryotic cells. Cyclosis helps in the circulation of materials in the cells.
  2. Flagellar Movements. Flagella perform locomotion In euglenoids and other flagellate pivots, Chlamydomonas and other unicellular/colonial motile green algae sperm, etc. Flagellate choanocytes bring about the circulation of water in the canal system of sponges.
  3. Ciliary Movements. Paramecium and other ciliates swim using cilia.
  4. Undulation movements due to plasma membrane as in fibroblasts.

Muscular System NEET Study Material

NEET Biology Kingdom Protista Types Of Muscles

  1. Three types of muscles have been categorized based on the structure of their fibres.
  2. Details discussed in a chapter on (Animal tissues)
  • Skeletal muscles (Striated muscles). These generate external movement associated with the skeleton, remain attached to bone through the tendon, under conscious control and hence also termed as voluntary muscle. In lower magnification, these have transverse stripes hence also called striped or striated muscles.
  • Smooth Muscles (Visceral muscles)
  • Unstriped; hence structurally different from striated and cardiac muscles.
  • Muscle cell spindle-shaped (not cylindrical) uninucleated each formed of single myoblast.
  • Actin filaments remain attached, to dense bodies in the cytoplasm.
  • There is no myofibril, no sarcomere and no Z-line.
  • Actin and Myosin filaments are not arranged in any pattern hence no striations.
  • Involuntary muscle, under ANS control, is found in visceral organs (visceral muscle).
  • Cardiac muscle. This is also striated muscle but under involuntary control, hence has a rhythmic pattern of contraction with varying frequency.
  • This is an untiring muscle (no fatigue) and keeps on acting lifelong.
  • Being striated it is structurally similar to skeletal muscle except for the presence of (0 Cross fibres, besides parallel fibres
  1. Intercalated discs – which represent the joints of two myoblasts.
  2. The contraction pattern is rhythmic and the rate of contraction is controlled by the autonomic nervous system (ANS).
  3. They do not get fatigued, and work ceaselessly throughout their lives.
  4. Generates impulse-like nerve (i.e. the myogenic heart of vertebrates).

NEET Biology Kingdom Protista Chemical Composition Of Muscle Fibres

  • Water 75%
  • Proteins 20% (Myosin, actin, tropomyosin troponin complex and enzymes)
  • Proteins of Muscles
  • Actin, the filament'(F-actin) is formed by polymerization of G-actin monomer. It has the site, occupied by regulatory protein troponin and tropomyosin, for the attachment of myosin.
  • Tropomyosin is a rod-shaped fibrous protein helically wrapped around the actin filament along its groove.
  • Troponin is a small globulin protein with l components: troponin-e, troponin-l and troponin-T masking the site on F-mMin lor attachment of myosin.

Muscular system Chemical Composition Of Muscle Fibres

  1. Myosin is a versatile protein with both fibrous and globular parts. The fibrous part aggregates to find the filament while the globular part, projects out at both ends as cross bridges or heads. 1 lead is formed of HMM (heavy mcromysoin) consisting of Sub-fragment-1 and the neck (or hinge). The tail part is formed of LMM (light meromyosin). The head acts as ATPnse which after connecting with actin hydrolyse ATP.
  2. Mineral and organic compounds 5% (K+ is the chief mineral constituent, Mg++, P++, Na+ and Ca+ 4  are present in minute quantities.
  3. Organic compounds are present in the form of glycogen, lipids, steroids and non-poric nitrogenous compounds.

NEET Biology Kingdom Protista Some Major Muscles

  1. Biceps. The front portion of the upper ami for bending of the arm at the elbow.
  2. Triceps. Back of upper arm for straightening of ami at the elbow.
  3. Biceps femoris. Back of thigh for bending leg at the knee.
  4. Quadriceps. Front of thigh
  5. Gluteus maximus. Buttocks.
  6. Gastrocnemius. Calves, bending of the ankle joint.
  7. Frontal. Fore-head.
  8. Orbicularis oculi. Closure of eyes.
  9. Orbicularis oris. Closure of mouth.
  10. Masseter. Mastication.
  11. Trapezius. Upper back and side of the neck
  12. Deltoid. Shoulder raises an arm.
  13. Pectoralis major. Lowers arm.

Muscular System NEET Question Bank

NEET Biology Kingdom Protista Features Of Muscle Fibers

  • Excitability. The skeletal muscle fibres can be excited by the nerve impulses generated in the motor nerve fibre by the specific stimuli. This power is maximum in striated muscle fibres.
  • Conductivity. The skeletal muscle fibres can conduct the excitation along the length of muscle fibres at the rate of 3-5 metres/second with the help of the T-tubule system and sarcoplasmic reticulum.
  • All or None Rule (Bowditch’s Law). When the skeletal muscle fibre is stimulated, it responds either by shortening or lengthening. The response of a muscle fibre is independent of the strength of the stimulus. If there is any response, it is maximum.
  • The minimum strength of stimulus (nerve impulse) required to bring about the response, is called threshold stimulus. It varies from fibre to fibre. If the stimulus is of a strength below the threshold stimulus, the muscle fibre is not excited, but if the stimulus has a strength equal to or higher than the threshold stimulus, the muscle fibre shows a maximum response.
  • The force of contraction does not increase with the increase in the strength of the stimulus. But in the case of whole muscle, the extent of contraction depends upon the number of motor units which are contracting at any particular period.

NEET Biology Kingdom Protista Useful Terms

  1. Latent phase or period. It is a brief time interval between the point of stimulation and the actual starting of response i.e. contraction phase. The duration of the latent period varies with the species, type of muscle, temperature and internal condition of the muscle.
  • It is due to the time taken for the propagation of impulse from the point of stimulation to the” neuromuscular junction and then to sarcolemma  for initiation of contraction (In frogs it lasts about 10 milliseconds in skeletal muscles and up to 3 sec. in visceral muscles.)
  1. Contraction phase. It is the time interval in which the muscle reaches the peak of contraction and performs work. (It lasts for 40 milliseconds in skeletal and 20 sec. in visceral muscles.)
  2. Relaxation phase. It is the longest of three phases. It lasts about 50 milliseconds in skeletal muscles, and 2.3 sec in visceral muscles and is indicated by downward tracing in the kymograph (graph showing a twitch contraction). During the phase, the muscle returns to its original length.
  3. Single Muscle Twitch. The response of a muscle to a single short stimulus, such as 1 electric shock is known as a twitch and can be recorded as a kymograph. A twitch can be divided into three successive phases.
  4. Motor unit. All muscle fibres supplied by a single motor neuron are called a motor unit. On average, there are 100 muscle fibres in a motor unit.
  5. Isotonic contractions. When a muscle contracts, with a constant load that it  can lift, it is said to be isotonic contraction In other words there is a change in the shape of the muscle and it maintains tension
  6. Isometric contractions. When a muscle contracts against a weight dial it cannot lift, it is called an isometric contraction. In other words, llicic is no change in the shape of the muscle. AS u maintains umfoim length.
  7. Tentas. It the muscle fibre is stimulated before it relaxes for a second time, it can contract again If we continue closely spaced stimuli, we gel a smooth sustained contraction, called a tetanus or tetanic contraction.
  8. Summation. If a second stimulus is applied to a muscle that is still in the contraction phase, a second contraction is added to die first and results in greater shortening of muscle than caused by a single stimulation. It is termed summation.
  9. Refractory period. (0.002 – 0.005 see in skeletal, 0.1-02 sec in cardiac muscle fibre.) If two stimuli are applied one immediately after the other, die muscle will respond to the first stimulus, but not to the second.
    1. The brief period during which the muscle does not respond to the second stimulus is called a refractory period or period of lost irritability. Its duration varies with the muscle involved. Skeletal muscle has a short refractory period w whereas cardiac muscle has a long refractory period.
    2. The absolute refractory period during which the recovering muscle fibre cannot be stimulated by a stimulus of any strength.
    3. The relative refractory period during which the muscle fibre can be excited only by a stimulus of strength higher than the previous strength of the stimulus.
  10. Fatigue. If muscle fibres are repeatedly stimulated to contract, these fibres take a longer time to respond to the excitation during contraction and also to complete relaxation.
  11. Their force of contraction also declines progressively. Finally, the fibres fail to contract at all for some time. It is known as muscle fatigue. It is caused by the accumulation of lactic acid and other changes in the muscle due to prolonged contraction.
  12. Site of muscle fatigue. Stephens and Taylor suggested that the site of skeletal muscle fatigue is the neuro-muscular junction and occurs when there is increased K+ concentration and decreased Na+ concentration in the ECF of the muscle fibres.
  13. Rigor mortis. Muscles become stiff after death. This state is called rigor mortis. It occurs due to the absence of ATP. It first appears in the muscles of the face and jaw. Rigour mortis disappears after three or four days because the proteins become soluble.
  14. Red muscle fibres contain myoglobin, arc thin, dark red and contain mitochondria. These are capable of doing more work and do not easily get tired.
  15. White muscle fibres are of light red or pink and do not contain myoglobin and mitochondria. Get easily tired and cannot work for long.

NEET Biology Kingdom Protista Muscle Contraction (Sliding Filament Theory)

  1. The sequence of myosin-actin bonding, sliding and release is repeated rapidly over and over until the muscle has shortened sufficiently. This is the sliding fuming mechanism for muscle contraction, and it consumes a great deal of ATP.
  2. When an individual muscle is stimulated, the actin filament in every sarcomere unit slides towards the middle of the sarcomere. As a result, the myofibrils shorten. A muscle cell shortens (contracts) then all its myofibrils shorten. An entire muscle contracts when many of its muscle cells contract simultaneously.
  3. Contraction ends when the muscle cell ceases to be stimulated by the nerve cell. If an impulse no longer travels down the T – tubules to the cell’s interior, Ca2+ is actively transported back into the SR.
  4. Without Ca2+, the troponin-tropomyosin protein complex shifts back into its original position, masking the sites on the actin filaments and preventing further bonding by the myosin heads. When this happens, the muscle relaxes and returns to its original shape.

NEET Biology Kingdom Protista Biochemical Aspects

  1. During contraction actin and myosin combine to form actomyosin, this was shown in vitro by Szent Gyorgi (1946), who won the Nobel Prize for this work.
  2. There are three basic pathways for providing energy to be utilised in muscle contraction.
  3. The hydrolysis of ATP provides free energy to the converted to mechanical energy by the interaction of actin and myosin. Here myosin plays the role of ATPase.
  4. ADP + CP + H+ → ADP + Pi + H+ ΔG
  5. The ATP molecule present in muscle cells lasts for only a few seconds of muscle action. Hence muscle mainly depends upon other phosphate molecules creatine phosphate (CP) as a source of energy stored it. This acts as a recharger of ADP. ADP + CP + H+ →ATP + C (Lohmann’s Reaction)
  6. This reaction was discovered by Lohmann (1932) which won him a Nobel Prize.
  7. After the CP of reserve is exhausted muscle resorts to glycolysis of glycogen. Whose end product is the lactic acid that causes fatigue.
  8. Oxygen debt. Till the entire amount of creatine phosphate is recovered through the regeneration of ATP by oxidative phosphorylation body remains in oxygen debt and to repay it the person keeps on panting after a strenuous exercise. Cori cycle. The accumulated lactic acid diffuses out of muscle through blood and reaches the liver where it is reconverted to glycogen.
  9. Troponin and Tropomyosin are two regulatory proteins present on this filament and are essential for the actin-myosin interaction i.e., muscle contraction.

Muscular system Difference Between Isotonic Contraction And Isometric Contraction

Muscular system Difference Between Red Muscle Fibre And White MuscleFibre

  1. When during muscle contraction, muscle length remains c& the same but tension increases then it is called isometric contraction For Example Holding some weight.
  2. When during muscle contraction, muscle length changes but tension remains constant then it is called isotonic contraction For Example during walking. c& Glycogen can be formed more readily from glucose in muscles.
  3. Carl Ferdinand Cori shared the 1947 Nobel Prize for physiology and medicine with his wife Gerty Theresa Cori and B.A. Houssary for their work on the metabolism of glycogen.
  4. Animals with“liquid skeleton”-Earthworms, Caterpillars (larvae of butterflies and silk moths), and Slugs. It gives shape and support to the body. c& In the case of non-chordates except echinoderms arginine is present in place of phosphocreatine.
  5. Sarcomere functional unit of contraction of a muscle.
  6. All or none law is also known as Bowditch’s law.  Biochemical and electrical events during muscle contraction were studied by Albert Szent Gyorgi Special conducting system of the heart consists of special cardiac muscle fibres.
  7. Treppe (Staircase phenomenon) A stimulus of constant strength applied regularly at clock intervals to a muscle produces a series of contractions, the first of which are of increasing amplitude.
  8. Glycogenolysis occurs in liver cells but not in muscle cells as these lack the Glucose-6 phosphatase enzyme. Troponin-Tropomyosin Complex prevents muscle contraction as it inhibits the activity of ATPase enzyme and prevents the formation of actomyosin complexes., Oxygen-Debt. Amount of extra oxygen consumed during the recovery after an exercise.
  9. Shivering involves the involuntary contraction of voluntary muscle fibres.
  10. 30-40 % of energy is used in contraction and the rest is converted into heat. This helps in warming the body.
  11. Roles of Muscle and Bones in Movement The force generated by muscle contraction pulls or lifts bone through tendons. Movement occurs along the joint, hence the bone actually acts as a lever having 3 parts :
  12. In the body joint acts as F, point of attachment of muscle to bone is E.
  13. There are 3 classes of levers:
  14. 1st class lever. F comes between E and R, very rare in the body, one such example is the head resting on the vertebral column.
  15. 2nd class lever. R comes between F and E, only a few in the body, For Example, raising the body on the toes.
  16. 3rd class lever. E remains in between the F and R, the most common type of lever in the body For Example, flexing the forearm at the elbow joint.

Muscular System NEET Mcqs

NEET Biology Kingdom Protista Questions From Competitive Examinations

Question 1. Immediate Source Of Energy For Muscle Contraction  Is:

  1. Glucose
  2. Gtp
  3. Creatine Phosphate
  4. ATP

Answer: 4. ATP

Question 2.  Which One Yields ATP Required For Muscle Contraction?

  1. Myoglobin
  2. Creatine Phosphate
  3. Creatinine Phosphate
  4. Myosin.

Answer: 2. Creatine Phosphate

Question 3. Edta Injected Into Muscles Combines With Ca2+ And :

  1. Stops Contraction
  2. Causes Contraction
  3. Slows Down Contraction
  4. None Of The Above.

Answer: 1. Stops Contraction

Question 4. What Is Sarcomere?

  1. Part Between Two H-Line
  2. Part Between Two A-Line
  3. Part Between Two I-Band
  4. Part Between Two Z-Iine.

Answer: 4. Part Between Two Z-Iine.

Question 5. Which Statement Is Correct For Muscle Contraction?

  1. Length Of H-Zone Becomes Decreased
  2. Length Of A-Band Remains Constant
  3. Length Of I-Band Becomes Increased
  4. Length Of Two Z-Line Become Increase,

Answer: 1. Length Of H-Zone Becomes Decreased

Muscular System NEET Exam Preparation

Question 6. Which light band Contains The following fluid protein?

  1. Myosin
  2. Actin
  3. Both 1 & 2
  4. None Of These.

Answer: 2. Actin

Question 7. Largest Skeletal Muscle Is Present In :

  1. Thigh
  2. Neck
  3. Arm
  4. Belly.

Answer: 1. Thigh

Question 8. Hinge Joint Is Present In :

  1. Elbow
  2. Pivot
  3. Interphalangeal
  4. Atlas.

Answer: 1. Elbow

Question 9. Biceps & Triceps Are Found In :

  1. Fore Arm
  2. Upper Arm
  3. Thigh
  4. Shoulder.

Answer: 2. Upper Arm

Question 10. Actin Filaments Depolymerise And Repolymerise In Motile Cells With :

  1. 0.2 – 0.3 Millisecond
  2. 1.0 – 2.0 Minutes
  3. 1 – 2 Hours
  4. 2-3 Days.

Answer: 1. 0.2 – 0.3 Millisecond

Question 11. Sacromere Occurs Between :

  1. Z – Line To Z – Line
  2. Two I – Bands
  3. Two Surfaces Of A Z – Line
  4. Two A – Bands.

Answer: 1. Z – Line To Z – Line

Question 12. “All Or None Law” Is Not Associated With .

  1. Muscle Fibre
  2. Tiruiun
  3. Cardiac Muscle
  4. Uriniferous Tubules

Answer: 4. Uriniferous Tubules

Question 13. ATPase Enzyme  Needed For Muscle Contraction Is Located In :

  1. Myosin
  2. Actin
  3. Actinin
  4. Troponin.

Answer: 1. Myosin

Question 14. Which Of The Following Is Important For Muscle Contraction And Nerve Impulse Transmission ?

  1. Ca2+ Ions
  2. Ca++ And Mg++ Ions
  3. Mg+ 4– Ions
  4. Fe 2+ Ions.

Answer: 2. Ca++ And Mg++ Ions

Question 15. During Strenuous Exercise Glucose Is Converted Into :

  1. Glycogen
  2. Pyruvic Acid
  3. Starch
  4. Lactic Acid.

Answer: 4. Lactic Acid.

Muscular System NEET Previous Year Questions

Question 16. Which Of The Following Is Not Syncytial ?

  1. Cardiac Muscle
  2. Skeletal Muscle
  3. Smooth Muscle
  4. Interstitial Muscle.

Answer: 3. Smooth Muscle

Question 17. The Condition In Which A Number Of Nuclei Are Present In A Muscle Fibre Is Called :

  1. Coenocytic
  2. Syncytial
  3. Polykaryon
  4. Endoduplicaton.

Answer: 2. Syncytial

Question 18. Contractile Tissues Have The Following Features :

A. Mesodermal In Orign

B. They Contain Stretch Receptors.

C. Rhythmic Contractions Are Seen In Them

D. Hey Do Not Fatigue During The Life Of The Animal.

Which Of The Above Are Characteristics Of Sphincters ?

  1. All The Four
  2. Only A, B And C
  3. Only A, B And D
  4. Only A, C And D.

Answer: 2. Only A, B And C

Question 19. The Lactic Acid Generated During Muscle Contraction Is Converted To Glycogen In :

  1. Muscle
  2. Kidney
  3. Pancreas
  4. Liver.

Answer: 2. cAMP

Question 20. In Heart Cells, Which One Serves As A Second Messenger, Speeding Up Muscle Cell Contraction In Response To Adrenaline ?

  1. cAMP
  2. cGMP
  3. GTP
  4. ATP
  5. AMP.

Answer: 1. cAMP

Question 21. The Contractile Protein Of Skeletal Muscle Involving Atpase Activity Is :

  1. Troponin
  2. A-Actin
  3. Tropomyosin
  4. Myosin.

Answer: 4. Myosin.

Question 22. The Globular Protein Molecule, Which Masks The Active Sites On The F-Actin Is :

  1. Troponin
  2. Myosin
  3. Tropomyosin
  4. Light Mbromyosin
  5. Heavy Meromyosin.

Answer: 1. Troponin

Question 23. Statements :

  1. A-Bands Of The Muscle Is Dark And Contain Myosin
  2. I-Hamls Air The Light Hands Ami Contain Actin
  3. During Muscle Contraction The A-band Contracts
  4. The Part Between The Two Z-Lines Is Called As Sacromere
  5. The Central Pan Of Thin Filament, Not Overlapped By Thick Filament Is Called H-Zone.

Of The Above Statements.

  1. 1, 3, and 5 Are Correct While 2 And 4 Are Incorrect
  2. 1, 2, 3 And 3 Are Correct While 4 Is Incorrect
  3. 1, 2 And 3 Are Correct While 4 And 3 Are Incorrect
  4. 1, 2 And 4 Are Correct While 3 And 3 Are Incorrect
  5. 1 And 2 Are Correct While 3, 4 And 5 Are Incorrect.

Answer: 4. 1, 2 And 4 Are Correct While 3 And 3 Are Incorrect

Question 24. All Or None Law Is Not Applicable To :

  1. Whole Skeletal Muscle
  2. Single Skeletal Muscle Fibre
  3. Whole Cardiac Muscle
  4. Single Smooth Muscle Fibre.

Answer: 1. Whole Skeletal Muscle

Question 25. The H-Zonc In The Skeletal Muscle Fibre Is Due To :

  1. The Central Gap Between Myosin Filaments In The A-Band.
  2. The Central Gap Between Actin Filaments Extending  Through Myosin Filaments In The A Band.
  3. Extension Of Myosin Filaments In The Central Portion Of The A-Band.
  4. The Absence Of Myofibrils In The Central Portion Of A-Band.

Answer: 2. The Central Gap Between Actin Filaments Extending  Through Myosin Filaments In The A Band.

NEET Biology Multiple Choice Questions – Muscular System

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NEET Biology Muscular System Multiple-Choice Questions

Question 1. Abductors Are Antagonists Of :

  1. Adductors
  2. Extensors
  3. Tlexois
  4. None Of These.

Answer: 1. Adductors

Question 2. The Non Striated Muscles are also referred to As The :

  1. Cardiac Muscle
  2. Voluntary Muscle
  3. Skeletal Muscle
  4. Involuntary Muscle.

Answer: 4. Involuntary Muscle.

Question 3. Fach Satvomcrc Consists Of Regularly Arranged Thick And Thin:

  1. Carbohydrate Filaments
  2. Fat Filaments
  3. Protein Filaments
  4. Vitamin Filaments.

Answer:  3. Protein Filaments

Question 4. The Dark Band Of The Protein Filament Is Called The :

  1. Anisotropic Band
  2. Isotonic Band
  3. Isometric Band
  4. Isotropic Band.

Answer: 1. Anisotropic Band

Read and Learn More NEET Biology Multiple Choice Question and Answers

Multiple Choice Questions On Muscular System For NEET Question 5. The Light Band Of The Protein Filament Is Called The :

  1. Isotaipic Band
  2. Isotonic Band
  3. Isometric Band
  4. Anisotropic Band.

Answer: 1. Isotaipic Band

Question 6. The Term ‘Refractory Period’ Concerning Muscle Tissue Refers To :

  1. A Period When Stimulation Does Not Lead To Contraction
  2. A Period When Maximal Contraction Occurs
  3. Time Gap Between Application Of Stimulus And Occurrence Of Contraction
  4. Loss Of Translucency In Muscle Fibres Due To Death Of Animal.

Answer: 1. A Period When Stimulation Does Not Lead To Contraction

Question 7. The Largest Muscle Of The Body Is :

  1. Biceps
  2. Gluteus Maximus
  3. Triceps
  4. Quadriceps.

Answer: 2. Gluteus Maximus

Question 8. Cori’s Cycle Operates In :

  1. Liver
  2. Liver And Muscles
  3. Nerve
  4. Muscles.

Answer: 2. Liver And Muscles

Question 9. The Muscle Used In Straightening A Limb Is Called :

  1. Elevator
  2. Flexor
  3. Extensor
  4. Depressor.

Answer: 3. Extensor

Multiple Choice Questions On Muscular System For NEET Question 10. Heart Beat Is Controlled By Specialized Muscles Whose Fibres Are Called :

  1. Purkinje Fibres
  2. Myonemes
  3. Telodendria
  4. Collagen Fibres.

Answer: 1. Purkinje Fibres

Question 11. Rigor Mortis Is Due To :

  1. Leakage Of Calcium Out Of The Sarcoplasmic Reticulum After Death
  2. Lack Of ATP
  3. Death Of The Motor Neuron
  4. Loss Of Electrical Potential Difference Across The Sarcolemma.

Answer: 2. Lack Of ATP

Question 12. The Extent Of Contraction Of A Mammalian Skeletal Muscle Is Controlled By :

  1. Interaction Of Excitatory And Inhibitory Nervous Input To Individual Fibres
  2. Contraction Of Some Sacromeres In A Muscle Fibre But Not Others
  3. Contraction Of Some Entire Muscle Fibres While Others Remain Relaxed
  4. All Of The Above.

Answer: 3. Contraction Of Some Entire Muscle Fibres While Others Remain Relaxed

Question 13. Krause’s Membrane Is:

  1. Z-Disc
  2. Sarcolemma
  3. T-System
  4. Neuromuscular Junction.

Answer: 1. Z-Disc

Question 14. Muscle Fatigue Is Due To Accumulation Of:

  1. Adp
  2. HCL
  3. 1actic Acid
  4. Creatine.

Answer: 3.  1actic Acid

MCQ on Muscular System Question 15. Which One Of The Following Proteins Is Both Structural And Enzymatic?

  1. Actin
  2. Troponin
  3. Myosin
  4. Trypsin.

Answer: 2. Troponin

Question 16. Muscles Arc Derived From Embryonic :

  1. Endoderm
  2. Ectoderm
  3. Mesoderm
  4. All Of These.

Answer: 3. Mesoderm

Question 17. The Immediate Source Of Energy For Muscle Contraction Is:

  1. NADH2
  2. ATP
  3. Glucose
  4. Pyruvic Acid.

Answer: 2. ATP

Question 18. For Each Phase Below, Give The, Type (S) Of Muscle That Show The Characteristic :

A. Syncytial                                                           1. Cardiac

B. Innervated By Autonomic Nervous System      2. Skeletal

C. Can Contract Without Nervous Stimulation     3. Smooth

D. Typically Found In Sheets Rather In Bundles.

Select The Correct Combinations :

  1. A-2,  B-2,3,   C-1,   D-3
  2. A-2,  B-1,     C-3,    D-2
  3. A-2,  B-1,3   C-1,    D-3
  4. A-3,  B-1,     C-1,3   D-3.

Answer: 1. A-2,  B-2,3,  C-1,  D-3

Question 19. Striated Muscles Contract By :

  1. Sliding Of Actin Filament Upon Myosin Filaments
  2. Sliding Of Myosin Filaments Upon Actin Filaments
  3. Pulling Together Of Myosin’filaments
  4. Pulling Together Of Actin Filaments.

Answer: 1. Sliding Of Actin Filament Upon Myosin Filaments

MCQ on Muscular System Question 20. Heart Muscles Are Called :

  1. Skeletal
  2. Visceral
  3. Cardiac
  4. Smooth.

Answer: 3. Cardiac

Question 21. A Striped Muscle Fibre Has:

  1. No Nucleus
  2. Many Nuclei
  3. Two Nuclei
  4. One Nucleus.

Answer: 2. Many Nuclei

Question 22. What Happens To The Muscle Due To Strenuous Exercise?

  1. Glucose Is Converted To Glycogen
  2. Fat Is Converted To Protein.
  3. Glucose Is Converted To Protein
  4. Pyruvic Acid Is Converted Intojuetic Acid.

Answer: 4. Pyruvic Acid Is Converted Intojuetic Acid.

Question 23. Strongest Muscles In Human Body Are Found In :

  1. Jaws
  2. Thighs
  3. Neck
  4. Hands.

Answer: 1. Jaws

Question 24. Cardiac Muscles Are Striped Muscles With Fibres Being :

  1. Syncytial And Voluntary
  2. Multinucleated And Involuntary
  3. Nucleated Aiul Voluntary
  4. Nucleated And Involuntary.

Answer: 1. Syncytial And Voluntary

Skeletal Muscle Basic Anatomy NEET Questions Question 25. Cardiac Muscles Contract :

  1. Slowly And Get Fatigued
  2. Quickly And Gel Fatigued
  3. Slowly And Do Not Get Fatigued
  4. Quickly And Do Not Gel Fatigue.

Answer: 4. Quickly And Do Not Gel Fatigued

Question 26. The Muscles Which Bring About The Movements Of The Body Are :

  1. Smooth
  2. Striated
  3. Cardiac
  4. Smooth And Striated Both.

Answer: 2. Striated

Question 27. The Distance Or Length Of The Myofibril Between Two Adjacent Z-Bands Is Called :

  1. Sarcomere
  2. Sarcolemma
  3. Fibril
  4. Sarcoplasm.

Answer: 1. Sarcomere

Question 28. The Smallest Functional Unit Of Striated Muscles Is Called :

  1. Sarcomere
  2. Myosin
  3. Neurilemma
  4. ATP-Molecule.

Answer: 1. Sarcomere

Question 29. In A Relaxed Fibril, H-Zone—A Lighter Region Of Low Density Can Be Seen In The Centre Of:

  1. Anisotropic Or A-Band
  2. Isotropic Or I-Band
  3. Z-Band.
  4. Both In A And I-Bands.

Answer: 1.  Anisotropic Or A-Band

Skeletal Muscle Basic Anatomy NEET Questions Question 30. The Myofilaments Which Make A Myofibril Are :

  1. Only Primary Or Thick
  2. Only Secondary Or Thin
  3. Both Primary And Secondary
  4. Medullated.

Answer: 3. Both Primary And Secondary

Question 31. The Number Of Secondary Filaments That Surround A Primary Filament In A Myofibril Is :

  1. 4
  2. 6
  3. 8
  4. 10.

Answer: 2. 6

Question 32. The Dark Bands In A Myofibril Are Due To Overlapping Of:

  1. Only Thick Bands
  2. Only Thin Bands.
  3. Both Thick And Thin Bands
  4. None Of The Above.

Answer: 3. Both Thick And Thin Bands

Question 33. The Light Bands In A Myofibril Are Due To The Overlapping Of:

  1. Primary Bands
  2. Secondary Bands
  3. Both Primary And Secondary Bands
  4. None Of The Above.

Answer: 2. Secondary Bands

Question 34. The Special Contractile Protein Actin Is Found In :

  1. Thick Filaments Of A-Bands
  2. Thin Filaments Of I-Bands
  3. Both Thick And Thin Filaments
  4. Whole Of Myofibril.

Answer: 2. Thin Filaments Of I-Bands

Question 35. The Thick Filaments Of A-Bands Contain A Special Contractile Protein Called :

  1. Actin
  2. Myosin
  3. Ossein
  4. Both Actin And Myosin.

Answer: 2. Myosin

Muscle Locomotion and Movement Class Biology MCQ Question 36. The Cross-Bridges In A Myofibril Arise As The Heads Of Molecules Of:

  1. Lyosin
  2. Actin
  3. Tropomyosin
  4. Elastin.

Answer: 1. Lyosin

Question 37. The Lime Interval Between Two Subsequent Contractions Of A Muscle Fibre During Which A Muscle Fibre Does Not Respond To A Stimulus Is Called :

  1. Incubation Period
  2. Refractory Period
  3. Gestation Period
  4. Excitatory Period.

Answer: 2. Refractory Period

Question 38. The Simple, Single Muscular Contraction Caused By A Single Short Stimulus Is Called :

  1. Tendon
  2. Twitch
  3. Refractory Period
  4. Tetanus.

Answer: 2. Twitch

Question 39. The Smooth Sustained Contraction Of A Muscle Due To the Fusion Of Many Twitches Is Called :

  1. Tendon
  2. Tetanus
  3. Muscular Fatigue
  4. Rigor Mortis.

Answer: 2. Tetanus

Muscle Locomotion and Movement Class Biology MCQ Question 40. The Contraction Of Muscles After Death Is Called :

  1. Rigor Mortis
  2. Tetanus
  3. Twitch
  4. Refraction.

Answer: 1. Rigor Mortis

Question 41. The Diminished Muscular Contraction Ability As A Result Of Prolonged Stimulation Is Called :

  1. Twitch
  2. Muscle Fatigue
  3. Tetanus
  4. Rigor Mortis.

Answer: 2. Muscle Fatigue

Question 42. The Muscular Contraction In Which The Tension Of The Muscle Increases Sharply, Length Of the Muscle Remains The Same And No Mechanical Work Is Done Is Called :

  1. Isotonic Contraction
  2. Tetanus
  3. Isometric Contraction
  4. Twitch.

Answer: 3. Isometric Contraction

Question 43. The Muscular Contraction In Which The Tension Remains The Same And The Mechanical Work Is Also Done Is Called :

  1. Isotonic Contraction
  2. Tetanus
  3. Isometric Contraction
  4. Single-Muscle Twitch.

Answer: 1. Isotonic Contraction

Question 44. The Muscular Fatigue Is Due To The :

  1. Lack Of ATP and Lactic Acid
  2. Lack Of Glycogen Atp And Lactic Acid
  3. Lack Of Lactic Acid And Glycogen
  4. Lack Of Glycogen, Atp And Excess Of Lactic Acid.

Answer: 4. Lack Of Glycogen, Atp And Excess Of Lactic Acid

Muscle Locomotion and Movement Class Biology MCQ Question 45. Polio Disease Is A Viral Disease Common In Children. It Affects :

  1. Skeleton
  2. Nervous System
  3. Muscles And Spinal Cord
  4. Skeleton And Nervous System.

Answer: 3. Muscles And Spinal Cord

Question 46. Which One Of The Following Acts As Phosphagen In The Vertebrates?

  1. Phosphocrcatinc
  2. Atp
  3. Phosphoric Acid
  4. Phosphoaigininc.

Answer: 1. Phosphocrcatinc

Question  47. The Total Weight Of Muscles In An Adult Male Is ;

  1. 10 Kg.
  2. 30 Kg
  3. 50 Kg.
  4. 70 Kg

Answer: 2. 30 Kg

Question 48. Minimum Strength Of Stimulus Required To Initiate Muscle Contraction Is :

  1. Twitch
  2. Threshold
  3. Tetany
  4. Rigor Mortis.

Answer: 2. Threshold

Question 49.  Biochemical Changes During Muscle Contraction Were Explained By :

  1. Huxley And Huxley
  2. Huxley. Huxley And Hansen
  3. Bohr
  4. Albert Szent-Gyorgi.

Answer: 4. Albert Szent-Gyorgi.

Question 50. Contraction Of Which Muscle Draws A Limb Towards Body Line?

  1. Abductor
  2. Hansen
  3. Adductor
  4. Triceps

Answer: 3. Adductor

MCQ on Muscular System Question 51. The Erect Posture Of A Man Against Gravity Is Constantly Maintained By :

  1. Back
  2. Biceps
  3. Red Muscles
  4. Triceps.

Answer: 3. Red Muscles

Question 52. The Fundamental, Repeating Unit Of Skeletal Myofibril Is The :

  1. Motor Unit
  2. Myosin Cross Bridge
  3. Sarcoplasmic Reticulum
  4. Sarcomeres

Answer: 4. Sarcomeres

Question 53. A Contraction Cycle (Muscle Twitch) Consists Of:

  1. A Latent Period
  2. A Contraction Period
  3. A Relaxation Period
  4. All The Above.

Answer: 4. All The Above.

Question 54. In Muscle Contraction, Sarcomeres Become Shorter. Which Of The Following Does Not Occur In This Process?

  1. Z Lines Come Closer
  2. A Bands Shorten
  3. I Bands Shorten
  4. H Zones Become Narrow.

Answer: 2. A Bands Shorten

MCQ on Muscular System Question 55. According To The Now Established Siiding Filamentmodel Of Muscle Contraction, The Molecules That Move To Shorteii A Muscle Are :

  1. Actin
  2. Myosin
  3. Collagen
  4. Creatine Phosphate

Answer: 1. Actin

Question 56. The Neurotransmitter Between A Motor Neuron And Muscle Cell Is :

  1. Serotonin
  2. Endorphin
  3. Dopamine
  4. Acetylcholine

Answer: 4. Acetylcholine

Question 57. During Muscle Contraction:

  1. Chemical Energy Is Changed Into Electrical Energy
  2. Chemical Energy Is Changed Into Mechanical Energy
  3. Chemical Energy Is Changed Into Physical Energy
  4. Mechanical Energy Is Changed Into Chemical

Answer: 2. Chemical Energy Is Changed Into Mechanical Energy

Question 58. The Ions That Help In Biochemical Events In Muscle Contraction Are :

  1. Na+ And K++
  2. Na+ And Ca++
  3. Ca++ And Mg4++
  4. Na+ And Mg++.

Answer:  3. Ca++ And Mg4++

Question 59. What  Is Not True Of The Primary  Or Thicker Myofilaments?

  1. Composed Of Myosin
  2. Confined To A Bunds
  3. Hem Cross Bridges
  4. Joined At Both Ends.

Answer: 4. Joined At Both Ends.

MCQ on Muscular System Question 60. The Ion That Must Lie Present For Binding Of Cross Bridges Is :

  1. Ca++
  2. Na+
  3. Fe++
  4. K+

Answer:  1. Ca++

Question 61. A Body Muscle Is Enclosed By A Sheath Called :

  1. Endomysium
  2. Perimysium
  3. Epimysium
  4. Fibroiis Capsule

Answer:  3. Epimysium

Question 62. When Muscle Remains In A Prolonged Contraction, It Is Called:

  1. Convulsion
  2. Muscle Twitch
  3. Tetanus
  4. Poliomyelitis.

Answer: 3. Tetanus

Question 63. Sliding Filament Theory Of’musclc Contraction Was Proposed By :

  1. Huxley
  2. Hansen
  3. Bohr
  4. Huxley, Huxley And Hansen

Answer: 4. Huxley, Huxley And Hansen

Question 64. Red Muscles Are Found On The Human

  1. Back
  2. Thorax
  3. Abdomen
  4. Head

Answer: 1. Back

Skeletal Muscle Basic Anatomy NEET Questions Question 65. Fore Arm Is Brought Towards Upper Arm By

  1. Supinator Muscle
  2. Depress Or Muscles
  3. Biceps
  4. Triceps.

Answer: 3. Biceps

Question 66. The instrument Used To Record The Muscle Twitch Is :

  1. Myograph
  2. Kymograph
  3. Electrocardiograph
  4. Phonograph

Answer: 2. Kymograph

Question 67. Parapodia Are Locomotory Organs Of:

  1. Earthworm
  2. Lumbricus
  3. Leech
  4. Nereis

Answer: 4. Nereis

Question 68. Atlas-Axis Joint Is :

  1. Hinge Joint
  2. Pivot Joint
  3. Angular Joint
  4. Saddle Joint

Answer: 2. Pivot Joint

Skeletal Muscle Basic Anatomy NEET Questions Question 69. Locomotion In Star Fish Occurs By :

  1. Tentacles
  2. Flagella
  3. Tube Feet
  4. Pseudopodia.

Answer: 3. Tube Feet

Question 70. Which Muscles Move The Fore’limb?

  1. Triceps Brachii
  2. Dorsal Scapularis
  3. Latis Sinus Dorsi
  4. Brachialis.

Answer: 4. Brachialis.

Question 71. In Birds Which Flight Muscle Is Well Developed?

  1. Alary
  2. Biceps
  3. Gastrocnemius
  4. Pectoralis Major.

Answer: 4. Pectoralis Major.

Question 72. Intercostal Muscles Are Found In :

  1. Fingers
  2. Thoracic Ribs
  3. Femur
  4. Radio-Ulna.

Answer: 2. Thoracic Ribs

Skeletal Muscle Basic Anatomy NEET Questions Question 73. Skeletal Or Striped Muscles Art

  1. Multinucleated, Cylindrical
  2. Syncytial
  3. Having Large Number Of Sarcosomes
  4. All Of The Above.

Answer: 4. All Of The Above

Question 74. In Muscle Fibres The Endoplasmic Reticulum Is Known As:

  1. Sarcoplasmic Reticulum.
  2. Poorly Developed
  3. Irregular In Shape
  4. Seen Only During Protein Synthesis.

Answer: 1. Sarcoplasmic Reticulum

Question 75. Biceps Muscle Connects Humerus With :

  1. Radius
  2. Ulna
  3. Scapula
  4. Pectoral Girdle

Answer: 1. Radius

Question 76. Smooth Muscles Air Pirsent In The :

  1. Ciliary Body
  2. Dermis
  3. Iris
  4. All Of These

Answer: 4. All OF These

Question 77. The Functional Unit Of The Contiaetlle System In The Striped Muscle Is :

  1. 2-Hand
  2. A-Band
  3. Myofibrils
  4. Sarcomere.

Answer: 4. Sarcomere

Question 78. The Total Number Of Muscles In The Body Of Man Is:

  1. 409
  2. 439
  3. 539
  4. 639

Answer: 4. 639

Question 79. The Gastrocnemius Muscle Is Attached To :

  1. Fore Arm
  2. Chest
  3. Thigh
  4. Shank.

Answer: 4. Shank.

Question 80. Addition Of One Contraction To A Previous One To Produce More Shortening Is :

  1. Summation
  2. Tetany
  3. Fatigue
  4. Rigor-Mortis.

Answer: 1. Summation

Question 81. A Sustained Contraction Of Muscle Due To Fusion Of Many Twitches Following Each Other In Succession Is Termed :

  1. Tetany
  2. Summation
  3. Fatigue
  4. Rigor-Mortis.

Answer: 1. Tetany

Muscle Locomotion and Movement Class Biology MCQ Question 82. The Muscles Undergo Contraction After Death. This State Of “Dead-Rigor” Is Called :

  1. Rigor-Mortis
  2. Tetanus
  3. Summation
  4. Fatigue.

Answer: 1. Rigor-Mortis

Question 83. Cori Cycle Occurs In :

  1. Liver
  2. Muscles
  3. Kidney
  4. Both 1 And 2.

Answer: 4. Both 1 And 2.

Question 84. Cori Cycle Is Associated With :

  1. Pyruvic Acid
  2. Oxalic Acid
  3. Lactic Acid
  4. Acetic Acid.

Answer: 3. Lactic Acid

Question 85. Contractile Proteins Include :

  1. Troponin
  2. Tropomyosin
  3. Actin And Myosin
  4. All The Three.

Answer: 1. Troponin

Question 86. Ciliary Muscles Are Found In :

  1. Diaphragm Of A Mammal
  2. Eyes Of Vertebrates
  3. Heart Of Vertebrates
  4. Stomach Of Frog.

Answer: 2. Eyes Of Vertebrates

Question 87. Which Of The Following Structures takes part In Locomotion And As Well As Feeding?

  1. Cilia
  2. Tentacles
  3. Limbs
  4. All Of The Above.

Answer: 4. All Of Above.

Question 88. Amoeboid Movement Help In Food Capturing And Change Of Place. Which Of The Following Are Involved In Pseudopodial Locomotion?

  1. Microfilament
  2. Cytosol
  3. Plasma Membrane
  4. All Of The Above.

Answer: 1. Microfilament

Muscle Locomotion and Movement Class Biology MCQ Question 89. In Humans, Muscles Constitute About Percent Of Total Body Weight:

  1. 10 – 20
  2. 20 – 30
  3. 30 – 40
  4. 40 – 50.

Answer: 4. 40 – 50.

Question 90. Visceral Muscles Are Smooth And Involuntary Except:

  1. Gut Muscles
  2. Bronchial Muscles
  3. Heart Muscles
  4. Arterial Muscles.

Answer: 3. Heart Muscles

MCQ on Muscular System Question 91. Which Of The Following Is Not True?

  1. Troponin Is A Part Of Thick Filament.
  2. Head Of  Myosin Has ATPase Activity
  3. Actin Is Present In Thin Filament
  4. H-Zone Of Striated Muscle Fibre Represents Both Thick And Thin Filament

Answer: 4. H-Zone Of Striated Muscle Fibre Represents Both Thick And Thin Filament

Question 92. Match Column 1 With Column 2.

Muscular system Match The Column 1 And 2 Question 92

  1. A – 5, B – 1, C – 3, D – 4
  2. A – 4, B – 3, C – 2, D – 1
  3. A – 1, B – 2, C – 3, D – 4
  4. A – 5, B – 1, C – 2, D – 4.

Answer: 1. A – 5, B – 1, C – 3, D – 4

Question 93. Which Of The Following Is Not True?

  1. At The Centre Of A – Band, A Comparatively Less Dark Zone Called H – Zone Is Present
  2. In The Centre Of H – Zone, M – Line Is Present
  3. Z- Line Is Located At The Centre Of The I – Band
  4. The H – Zone Contains Only Thin Filaments.

Answer: 4. The H – Zone Contains Only Thin Filaments.

Question 94. Myosin Molecule Of Muscles Is Formed Of A Tail And Head. The Tail Is Formed Of:

  1. T- MM
  2. H-MM
  3. Both L – MM And H – MM
  4. IFs.

Answer: 2. H-MM

Question 95. Which Of The Following Is Not A Feature Of Myosin Molecule?

  1. Contractile Nature
  2. ATPase Like Action
  3. Formation Of Cross Bridge With Active Site Present In The Actin
  4. All Of The Above.

Answer: 4. All Of Above.

Question 96. Intercostal Muscles Are Found In :

  1. Digits
  2. Pectoral Girdle
  3. Pelvic Girdle
  4. Thoracic Ribs.

Answer: 4. Thoracic Ribs.

Question 97. If A Solution Of Actin Is Mixed With A Solution Of Myosin The Resulting Mixture Becomes Very Viscous. If Atp Is And Atp Is Hydrolysed To Adp And Inorganic Phosphate. The Mixture Regains Viscosity Tfttl The Atp Is Hydrolysed. These Observations Suggest That:

  1. Actin And Myosin Bind Together.
  2. The Complex Of Actin And Myosin (Actomyosin) In An ATPase
  3. Atp Seems To Alter The Binding Between Actin And Myosin
  4. All Of The Above.

Answer: 4. All Of Above.

Question 98. One Of The Following Is A Wrong Match.

  1. Cardiac Muscles – Maximum Atp, Mitochondria And Intercalated Disc Characteristic
  2. Striated – Syncytial
  3. Cardiac – Lack of Autonomic Nerve Supply
  4. Sifiooth – Controlled By the Autonomic Nervous System  Mainly.

Answer: 3. Cardiac – Lack Autonomic Nerve Supply

Question 99. Origin Of Muscular System In Vertebrates Is :

  1. Ectoderm
  2. Endoderm
  3. Mesoderm
  4. Both 1 And 2.

Answer:  3. Mesoderm

NEET Biology Notes – Cell The Unit of Life

by

NEET Biology Cell Unit Of Lift And Structural Organisation

All living organisms consist of many coordinated compartments known as cells.

  1. Robert Hooke (1665) was the inaugural individual to employ the term ‘cell.’
  2. In 1831, Robert Brown identified a nucleus within orchid roots.
  3. Cytology: The discipline focused on the scientific examination of cells is known as cytology.
  4. The inception occurred in the early 17th century with the initial utilization of microscopes by Hooke, Grew, and Malpighi.
  5. Cellular biology: A comprehensive examination of a cell, considering its structure, functions, biochemical characteristics, reproduction, energy dynamics, division, development, and differentiation.
  6. Cell theory: German scientists Schleiden and Schwann proposed the cell theory, which asserts that all living organisms consist of cells.

NEET Biology Cell Unit Of Life Present Day Concept Of Cell Theory

  1. The body of almost all living organisms is an assemblage of cells or the cell constitutes the structural unit of all living organisms.
  2. Each cell represents a unit of metabolic activities because all the characteristics of life are performed within the cell.
  3. Cells are hereditary units also as they contain hereditary materials inside the nucleus.
  4. New cells originate from pre-existing cells. (R. Virchow 1858).
  5. All the activities are the outcome of the activities of its constituent cells.
  6. All the cells are capable of independent existence and they work as autonomous units.
  7. In multicellular organisms, a clear-cut division of labour can be noticed. However, cells are still dependent partly on each other.

Read and Learn More NEET Biology Notes

Cell The Unit Of Life NEET Notes

Cellular totipotency is the ability of a somatic cell of a plant to produce a new complete plant.

  • Steward et al. showed the phenomenon of cellular totipotency in carrot cultures,
  • Unicellular organisms are capable of performing all the metabolic activities.
  • For an efficient cell, the ratio of volume to surface area should be high.
  • A cell represents itself in two forms i.e. as an individual and as part of the continuity of cells.
  • Multicellular organisms are adapted for better survival.
  • Growth and synthesis of protoplasm are due to the nucleus of the cell.
  • Cytoplasm (mesoplasm cytosol or kinoplasm) is protoplasm except nucleus.
  • Protoplasm is a reversible crystallocolloidal solution. Term cytoplasm was given by Kolliker.
  • Hyaloplasm is cytoplasm outside the nucleus.
  • Cytoplasm coagulate when treated with acids/bases or heated above 60°C.
  • AH, physical and chemical changes tend to proceed in such a direction that useful energy undergoes irreversible degradation into a random form called entropy.
  • pH (powered hydrogen) or puissance hydrogen of cytoplasm, nucleoplasm and human blood is 6.9 ± 0.2, 7.4 ± 0.2 and 7.34 ± 0.2 respectively.

Cell Unit Of Life Structural Organization Main Cell Structures And Their Functions

NEET Biology Cell Unit Of Life Types Of Cell

Prokaryotic cell. A primitive cell which lacks a nuclear membrane, or nucleolus, possesses 70S ribosomes, membrane-bound organelles absent, and naked DNA present, also called a nucleoid or genophore or chromosome or fibrous nucleus or incipient nucleus, Example Bacteria, Blue green algae, PPLO etc.

Mesokaryotic cell. It is characterized by the absence of deoxyribounyleohistone; however, well well-defined nucleus is present. A peculiar type of division called dino mitosis occurs. Dodge used the term for cells of dinoflagellates (a type of algae). Eukaryotic cell.

Present in higher organisms. It possesses a true nucleus, DNA is associated with histone proteins called chromatin. Membrane-bound cell organelles present.

Cell Unit Of Life Structural Organization A Plant Cell

Cell Unit Of Life Structural Organization An Animal Cell

Cell Structure and Its organelles

  • A cell is a specific combination of organelles and is usually a microscopic bit of complex organized matter.
  • Cytoplasm is a complex mixture of organic and inorganic matter. It is amorphous and gel-like, containing various organelles.
  • The part of the cytoplasm outside the organelle is called cytosol which contains a system of microfilaments. It acts as a store of vital chemical activities and also as a site of certain metabolic activities like glycolysis and biosynthesis of fatty acids and certain proteins.
  • Cytoplasmic streaming or cyclosis helps in the formation of pseudopodia and the movement of organelles and other cell inclusions.

NEET Biology Cell Unit Of Life Cell Organelles

Cell organelles are of the following types depending upon several membranes.

  1. Single unit membrane-bounded organelles. Microbodies (Peroxisomes, Glyoxysomes, Sphaerosomes, Lysosomes, Golgi bodies, ER, vacuoles.)
  2. Double unit membrane-bounded organelles. Plastids, Mitochondria and Nucleus.
  3. Amembranous organelles: Ribosomes, centrioles, spindle, microfilaments and microtubules.

Endoplasmic Reticulum

The endoplasmic reticulum [ER] consists of an interconnected system of membrane-bound channels in the cytoplasm. It forms 30 to 60% of the total membranes of eukaryotic cells.

Electron microscopic observations by Porter, Claude and Fullam (1945) revealed a network of delicate strands and vesicles in the cytoplasm. The term endoplasmic reticulum was first used by Porter and Kallman (1952).

Cell Unit Of Life Structural Organization Various Components Of Endoplasmic Reticulum

The endoplasmic reticulum consists of cisternae, tubules and vesicles. It occupies 10% of the total cell volume. The cisternae are broad, flat, membrane-bound spaces arranged parallel to each other to form lamellae.

They are interconnected with each other. The tubules are 50 -100 A in diameter and appear as circles in sections. The vesicles or sacs appear as membrane-bound isolated globular cavities.

There are two morphological types of the ER. When some elements of ER are studded with small granules called ribosomes, it is called rough or granular ER. The other type is smooth or agranular, marked by the absence of these granules.

The strands of HR consist of biomembranes formed of lipoprotein and the space between them varies. SER in muscles is called sarcoplasmic reticulum and myeloid bodies in pigmented epithelial cells and retina of the eye. Ergnstoplusm is the basophilic region of cytoplasm containing RER. Desmotubiiles arc extensions of ER through plasmodesmata.

Cell The Unit Of Life NEET Notes

Functions. The ER and nuclear membrane arc are directly connected. The ER is connected with intercellular transport and cellular metabolism. ER also plays an important role in the synthesis of nuclear membranes during cell division. It also helps in protein synthesis, glycogen synthesis and storage, lipid synthesis and storage and formation of microbodies.

The ER gives additional mechanical support to the colloidal structure of cytoplasm and increases surface area for absorption.

Synthesis of steroids and hormones and the formation of visual pigments from vitamin A are also associated with ER. It synthesizes ascorbic acid and also takes part in detoxification of toxic chemicals.

NEET Biology Cell Unit Of Life Ribosomes

Ribosomes. Ribosomes are nucleo-protein protoplasmic subspherical structures without a covering membrane, negatively charged with a diameter of 150 to 250 A meant for a polypeptide or protein synthesis.

They were discovered by Palade and thus called “Palade particles”. These arc smallest ameinbranous cell organelles. Later these were named ribosomes. These are present in cytoplasm in the form of groups, called polysomes. Ribosomes are made up of ribonucleoprotein.

Ribosomes are of two basic types: 70S ribosomes in Bacteria and Blue-green algae, mitochondria and chloroplast, and 80S ribosomes in Eukaryotes. A 70 S ribosome has three molecules of r RNA 16 S, 5 S, 23 S, and 50 proteins mols.

80 S ribosome has four mols of rRNA (5 S, 5.8 S, 18 S and 28 S) and 80 mols of proteins. The 70S ribosomes are inactivated by the antibiotic Chloromycetin. The 80 S ribosomes are inactivated by cyclohexamide.

Ribosomes 80 S contain 40% and 60% RNA and protein respectively. Ribosomes are the seats of protein synthesis.

In mammalian mitochondria, ribosomes are of 55 S type. Proteins of all ribosomes are similar but it is the RNA which differs from ribosome to ribosome.

Prokaryotic And Eukaryotic Cells Differences NEET

Ergosomes or Polyribosomes (Rich 1963) are formed by protein synthesis.

  • A tenfold increase in Mg2+ cone unites ribosomes to form Diamers. 70 S ribo some form 100 S while 80 S forms 120 S. If cone, is decreased by 10 folds, the ribosomes disassociate. Only unemployed ribosomes disassociate while active or those involved in protein synthesis do not disassociate.
  • Lnke in 1976 proposed an asymmetrical model whereas Stefflar and Whittman, 1977, proposed a quasisymmetrical model for ribosomes.
  • About 75 % of the ribosomes of cells remain bound to the C-face of the E.R. membrane through a glycoprotein ribophorin. In the case of He La cells the number of ribosomes is 15%.

Cell Unit Of Life Structural Organization Ribosomes

  • Proteins of all ribosomes are similar, however, it is r RNA that differs from one ribosome to another ribosome.
  • Proteins synthesized on free ribosomes are used within the cell and those synthesized on bound ribosomes are used outside the cell.

Golgi Complex

Cell Unit Of Life Structural Organization Three Dimensional Structure Of Golgi Apparatus

Golgi Complex. These structures are also known as dictyosomes, gold some, idiosomes, Golgi apparatus or hypochondria, Dalton’s complex or Baker’s body.

In 1898, an Italian neurologist C. Golgi described certain previously unknown bodies in the cytoplasm of nerve cells of bam owls and cats using a special stain, Earlier the Golgi complex was thought to be present only in animal cells but recent research has shown that is present in plant cells.

Dalton and Felix observed them under TEM

Three distinct components are visible in the Golgi complex, they are

Tubularorflattened fluid-filled sacs or cisternae, each is membranous and parallel or concentrically with a convex (forming) surface towards the plasma membrane and the opposite concave surface is termed maturing surface,

Transition vesicles are small drop-like structures Secretory vesicles are present on the sides and the maturing face of Golgi.

Cell Organelles Structure And Functions NEET Biology

The elements of the Golgi complex may arise from ER, nuclear membrane or the pre-existing dictyosomes. It contains lipids, proteins and glycoproteins. Phosphatases, RUA, Phospholipids, ATP ases and S-nucleotidases are also present.

The metallic impregnation technique (osmium chloride silver salts)

NEET Biology Cell Unit Of Life Mitochondria

Mitochondria (Mito = thread, chondrion = granule) were discovered by Kolliker (1850) and the name mitochondria was given by Benda. Altman (1886) called them as ‘bioplasts’. He considered them as symbionts comparable to bacteria. In plants, mitochondria were discovered by Meaves (1904) in Nymphaea.

Cell Unit Of Life Structural Organization Three Dimensional Diagram Of a Mitochondrion Cut Longitudinally

Mitochondria are also called Chondriosomes or Chondriomites plastochondria or filavermicules or bioplasts.

Mitochondria occur in the cytoplasm of plants and animal cells, the average length of the mitochondrion is 3 to 5 microns and the average diameter is 0.5 to 1.3 microns. They can be stained with Janus green B.

Using ultra vibrations and detergent actions, two membranes of mitochondria can be separated to study their structure. The mitochondrion without an outer membrane is called a mitoplast.

The mitochondrion is bounded by two membranes, the outer membrane and the inner membrane.

There are two chambers. The space between the two membranes is called the outer chamber and the space bounded by the inner membrane is called the inner chamber. The inner membrane forms mitochondrial cristae.

The enzymes of the Krebs cycle, flavo-proteins and cytochromes are present in mitochondria which are the centre of respiration. Mitochondria are also involved in oxidative phosphorylation and ATP synthesis. These are also called as ‘Power house’ of the cell.

Mitochondria arise from pre-existing mitochondria or ER. Mitochondria are semi-autonomous bodies. Nass, Nass and Afzeluis (1965) have shown the presence of DNA in mitochondria (MDNA). It constitutes 17c of the total DNA of the cell.

It is a double double-stranded, naked, granular, slim, long molecule with a higher G-C ratio. It is a circular molecule in most higher animal cells but is linear in several eukaryotic plant cells. Ribosomes arc of 70S type (55S ribosome in mitochondria of mammals) RNA and 70 types of enzymes are present.

Cell Organelles Structure And Functions NEET Biology

The mitochondria of whole cells are collectively called chondriosome or chondriomes. On cristae are present oxysomes or F0—Fj particles which are tennis racket-shaped bodies.

These particles were discovered by H.F. Moran and Chanre. These are also called as ETS particles as electron transport systems and ATP synthesis occurs on them. Besides this, mitochondria are concerned with lipid synthesis and elongation of fatty acids.

In prokaryotes where mitochondria are absent, the site for oxidative phosphorylation and electron transport, including dehydrogenases is the plasma membrane.

Single mitochondrion occurs in the case of:

  • Microsterias Trypanosoma Chlorella.
  • The maximum number is 5,00,000/cell in flight muscles.
  • Meaves first to observe mitochondria in plants (Nymphaea).
  • They can be stained by Gentian Violet and Janus green B.
  • Cytochrome oxidase is present in the inner mitochondrial membrane.
  • Mitochondria are rich in Mn. They are yellow due to riboflavin. They live for 5×10 days membrane only
  • In all probability, the mitochondria arise from the nuclear envelope by evagination or by division of pre-existing mitochondria.
  • Pyruvic acid enters mitochondria and is converted to Co. A in per mitochondrial space.
  • ATP molecules are synthesised in the head.
  • There are 5 chemical complexes. The first four constitute the electron transport system and the fifth transfers and conserves energy and (helps in) ATP synthesis.
  • Mobile carriers = CoQ and Cyt C.
  • Flavoproteins are located in Complex 1

NEET Biology Cell Unit Of Life Lysosomes

Lysosomes are diminutive vesicles encased by a singular membrane that contain hydrolytic enzymes in crystalline or semicrystalline forms.

  • Christian de Duve discovered them. Lysosomes are present in nearly all animal cells, with the exception of mammalian red blood cells.
  • Their diameters are 0.4 and 0.8 ™. These are lacking in plant cells; nevertheless, P. Matile (1964) has identified them in the fungus Neurospora.
  • They are also referred to as ‘Suicidal bags’ or ‘Atom bombs’ due to their containment of hydrolytic enzymes.
  • Lysosomes are most abundant in white blood cells, macrophages, osteoclasts, and similar cell types.
  • Plant cells are devoid of lysosomes, with the exceptions of Neurospora, maize root tips, yeast, and the seeds of peas and cotton. Lysosomes originate from the M face of the Golgi apparatus.
  • Lysosomes execute various duties, including the digestion of food, the phagocytosis of foreign particles, involvement in metamorphosis, scavenging, supplying enzymes for the degradation of egg membranes, and facilitating the disintegration of ageing and dead cells.
  • Lysosomes eliminate toxins through engulfment and appear to be crucial for cellular division.
  • Additionally, they have an inherent mechanism that allows a cell to adapt.

Cell Unit Of Life Structural Organization Diagram Representing The Dynamic Aspects Of The Lysomes System

Lysosomes exist in more than one morphological form, hence show polymorphism and they are of the following four types:

  • Primary lysosomes (also known as original lysosomes storage granules or inactive lysosomes).
  • Secondary lysosomes (heterolysosome or phagolysosome heterophagic vacuoles or digestive vacuoles).
  • Autophagic vacuoles (autolysosomes or autolysosomes).
  • Residual bodies (telo lysosomes dense bodies or tertiary lysosomes).

NEET Biology Cell Unit Of Life Plastids

Plastids. Plastids (Haeckel, 1866) are semi-autonomous organelles having DNA and a double membrane; envelope which synthesizes or stores different types of organic compounds.

The chloroplasts are green plastids (Schimper 1833) which take part in the synthesis of organic food from inorganic raw materials in the presence of radiant energy or light and the process is termed photosynthesis.

Cell Unit Of Life Structural Organization Schematic 3 Dimensional Strucural Diagram Of A Chlorplast

Eukaryotic plants contain a heterogeneous group of cell organelles called plastids which vary in morphology and function, some plastids are colourless, called leucoplasts. They store reserve materials, such as starch, proteins and lipids.

Green plastids are called chloroplasts which contain chlorophyll. Still others the chromoplasts. contain carotenoids which are brilliant red or yellow.

All three plastids differentiate from small spherical amoeboid structures 0.4 to 0.9 um in diameter called proplastids. Plastids are the largest cell organelles.

The increasing order of plastid size is as follows:

Chloroplast → chromoplast → elaioplast → aleuroplast → amyloplasts.

The distribution of pigment systems are coupling factor in thylakoid membranes. The chloroplasts are usually discoidal or lens-shaped double membrane organelles.

They are made up of chlorophyll a and b carotenoids, lipids, proteins and nucleic acid. DNA in chloroplast was reported by Ris and Plaut.

The chloroplasts are ‘autonomous bodies and. thus, are also called “cells within cell organelle.” The membrane-bound matrix of chloroplast is called stroma where dark reaction or Calvin cycle of photosynthesis takes place. In the stroma are present thylakoids which form grana acting as site of light reaction where assimilatory power (ATP 4- NADPH,) are synthesized.

Fluid Mosaic Model Of Cell Membrane NEET Study Material

The smallest and most functional unit of chloroplast is called the photosynthetic unit or Quantosome. The term Quantosome was given by Park and Biggins (1964).

Each Quantosome consists of 250 molecules ofchlorophyll. The molecular weight quantosome is 2 x 106.

The size ofquantosome is length = 1 80 A width = 155 A and thickness = 100 A. It is considered that chloroplasts might have originated from a symbiotic relationship between an autotrophic microorganism capable of transforming energy from light and a heterotrophic cell.

Cell Unit Of Life Structural Organization Quantosome

  • Thylakoid membrane consists of 2 photosystem complexes namely photosystem 1 and photosystem 2 their reaction centres being P-700 and P-680.
  • LHCP = Light-harvesting complex protein. It is present in the thylakoid membrane and is photochemically inactive.
  • Plastids are called intracellular parasites and a symbiont hypothesis is used to explain them.
  • The plastidial system carrying genetic information is called the plastidome.
  • Chloroplast of higher plants chemically is composed of
  • Protein: 33-35%
  • Chlorophyll: 9%
  • Lipids: 20-30%
  • Carotenoids: 4-5%
  • Nucleic acids : 3-4%, traces of Vit K and A, Ribosomes 70
  • Protein lipid ratio in the chloroplast is 40: 30
  • No. of grana in chloroplast ranges from 10-100
  • C4 plants have dimorphic chloroplasts.
  • Chloroplasts move in the cell due to cyclosis.
  • Chloroplast is more important than chlorophyll as carotenoids in chloroplast protect chlorophyll from photo-oxidation.
  • Chloroplasts with nitrogen-fixing genes are called nitroplasts.
  • The three kinds of plastids are interconvertible

Cell Unit Of Life Structural Organization Chromoplast

Classification based on pigmentation.

  1. Chromoplast: coloured plastids
  2. Chloroplast: ‘Chlorophyll a & b c.g. green algae
  3. Phaeoplast: Fucoxanthin Example brown algae, diatoms.
  4. Rhodoplast: phycoerythrin Example red algae
  5. Blue-green chromoplast, ‘phycocyanin Example Blue-green. Algae
  6. Leucoplast colourless plastids
  7. Amyloplast: Starch storing
  8. Elaioplast (Oleasome): Fats storing.
  9. Aleuroplast (Proteinoplasts) : protein storing.

Shapes

Cell Unit Of Life Structural Organization Classification ob the basis of Pigmentation

  • The chlorophyll in grana is surrounded by 2 protein layers (Y-shaped) in between the protein and chlorophyll there occurs lipid chlorophyll.
  • Leaf palisade mesophyll cells of higher plants contain 20-40 chloroplasts.
  • Single thylakoid occurs in the granum of Rhodophyceae.
  • Quantosome is believed to have (160 a + 70 b) chlorophyll and 50 carotenoid molecules.
  • Chloroplasts which lack granum are often described as agranal or Kranz type.

NEET Biology Cell Unit Of Life Microbodies

Peroxisomes (Uricosomes)

These are single membrane-bound vesicles with a size ranging from 0.5 to lim. They were discovered by Tolbert and the term peroxisome was coined by de Duve (1969) for those microbodies which are rich in enzymes peroxidase classes and catalases and produce hydrogen peroxide during their degrading activity.

These vesicles contain fine, granular substances that may condense to form a central core or nucleoid.

The peroxisomes without nucleoids are called micro-peroxisomes. The enzymes present are:

  • Uric acid oxidase
  • α – amino acid oxidase.
  • α – Hydro xylic acid oxidase.
  • β Hydroxylic acid oxidase.
  • NADH-glyoxalate reductase.
  • NADH-isocitrate dehydrogenase.
  • Catalase.
  • Peroxidase.
  • Peroxisomes generally arise from ER. These bodies take part in H202 metabolism and in green plants, they carry out photorespiration.

Sphaerosomes

Hanstein (1880) observed small highly refractive bodies of a denser substance in the cytoplasm of plant cells and later Danglard termed them sphaerosomes. They are microbodies which take part in the storage and synthesis of fats.

They were first discovered by Perner in 1953. Sphaerosomes are small spherical and refractile vesicles which are 0.5— 1.0 mm in diameter.

They arise from the ER and are surrounded by a single membrane. 98% of a phagosome is fat. Proteins constitute the remaining 2%. Some proteins are probably enzymatic and take part in the synthesis of fats.

Fluid Mosaic Model Of Cell Membrane NEET Study Material

Because of the presence of fat, phagosomes can be seen under light microscope after staining the cells with Sudan dyes and osmium tetraoxide. Sphaerosomes occur abundantly in the endospermic cells of oil seeds.

Sphaerosomes of some tissues Example tobacco endosperm, and maize root tips contain hydrolytic enzymes. Therefore, they are considered to have lysosomic activity.

Glyoxysomes

  • They are microbodies which contain enzymes [5-oxidation of fatty acids and glyoxalate pathway. These microbodies were discovered by Breidenback and Beevers (1967) from the extracts of the endosperm of germinating castor beans.
  • They are also present in the cells of some fungi. Like other microbodies, glyoxysomes have a single covering membrane and a matrix with a crystalloid core.
  • The matrix contains enzymes for (3-oxidation of fatty acids to produce Acetyl CoA. The latter is metabolised in the glyoxylate cycle to produce carbohydrates.

Lomasomes

They were discovered by Moore and McAear (1961) and are often referred to as border bodies. These bodies are present between the cell wall and cell membrane of both lower and higher plants. They play a role in secretion, increasing the surface area for the diffusion of substances involved in cell wall formation or breakdown in membrane proliferation and endocytosis.

Transosoines

  • These bodies were discovered by Press (1964) and are so far known to occur only in the ovarian follicles of birds.
  • These are circular and consist of triple-bonded envelopes with several ribosome-like granules attached by short stalks to the innermost band. It is believed that they have a role with the developing yolk granules but their exact function is not known.

NEET Biology Cell Unit Of Life Centrioles, Cilia And Flagella

Centrioles. They were first observed by Van Benden in animal cells. They are minute microtubular rods which can help to form their duplicates without having DNA and membranous covering.

Usually, two centrioles called diplosomes are present near the nucleus of all eukaryotic animal cells, primitive plants and all eukaryotic where flagellate structures and all eukaryotic plants where flagellate structures are present.

Mature centrioles are 0.2 lim in diameter and vary in length from 0.2 to 0.5 pm. A pair of centrioles surrounded by a clear area of cytoplasm, the centrosphere, is called a centrosome. Each centriole consists of nine sets of microtubules arranged circularly.

These tubules are equally spaced. Each microtubule is a triplet (diameter 250 A) of microtubules or subfibres embedded in a matrix designated as A, B, C and from inner to outer subfibre. Each subfibre is made up of 11—13 protofilaments of tubulin. The A-subfibre of a triplet is attached to the C-subfibre of the adjacent triplet by strands called linkers.

The central hub is (20 A in diameter), and from it arises 9 proteinaceous connectives called spokes, one towards subfibre.

Mitochondria And Chloroplasts Roles NEET Exam Preparation

A thickening ‘X’ is present at the outer end of each spoke and another Y is present between the two X thickening and are connected.

There are dense, amorphous, protoplasmic structures called macule satellites or pericentriolar structures on the surface of centrioles. Centrioles are locomotory structures and their role in cell division is acquired secondarily.

Cilia and flagella

  • (Studied by Englemann and confirmed by Jensen 1881) are hair-like protoplasmic processes of cells capable of undergoing movements and thus create a current jn -any fluid for locomotion and passage substances.
  • Both cilia and flagella have the same basic structure and differ in number, size and type of movement.
  • Chemically, they are mainly formed of protein and lipids, traces of carbohydrates and nucleotides are also present. Tubulin protein occurs in peripheral fibrils while dynein is found in the side arms of A-subfibrils spokes and central fibrils.

Structure

  • The cilia and flagella are essentially of the same structure and both arise from basal bodies. Cilium is surrounded by a membranous covering which is an extension of the plasma membrane. Both the membranes are separated by a space of 90 A.
  • The space between the limiting membranes of the cilium is filled with a matrix. In the matrix is embedded axial fibril complex.
  • The central axial filament complex consists of eleven microtubules arranged in two radii; out ofthese nine are double and are situated at the periphery and two single microtubules are placed in the centre.
  • Each of the nine outer tubules is 360 A in diameter and composed of two subunits. A sheath surrounds the central fibrils. The outer fibrils bear a pair of arms Radial lamellae, each with a thin secondary fibril, occur between central and outer fibrils.
  • Central singlet fibres are made up of a protein dynein with ATP-ase activity. Outer double fibres are made up of tubulin protein while A-B linkers are composed of protein nexin.

NEET Biology Cell Unit Of Life Cytoskelclal Supporting Structures

  • Intermediate filaments are long, unbranched having structure intermediate between microtubules and microfilaments and consist of a head, central rod and tail. First discovered in muscle cells (1968).
  • Microtubules earlier called neurotubules were first discovered by Sabatini, Bensch and Barnette (1963).
  • Microtubules and microfilaments form a complex structural framework of the cell. They are concerned with movement by or within the cell. They also can maintain the shape of the cell.
  • Microfilaments are long, thin, cylindrical rods composed of actin (protein).
  • Microfilaments are 6-10 nm in diameter and contract with the help of myosin.
  • Microfilaments may extend into the cytoplasmic core of microvilli.
  • Microfilaments are responsible for movement of the plasma membrane during cell mobility and endocytosis; contraction of muscle fibres and movement of microvilli.
  • Microtubules are elongated unbranched, cylindrical tubes of about 25 nm in diameter.
  • Each tubule encloses a light central core of 15 nm diameter. The microtubule’s wall is made up of 13 longitudinal filaments, each is a polymer chain of tubulin protein.
  • Microtubules occur singly or in bundles in cytoplasm radiating from the controls to the peripheral parts.
  • These form the skeleton of cilia and flagella and spindle during cell division helping in the movement of chromosomes. They can be broken down and reassembled in another part of the cell.

NEET Biology Cell Unit Of Life Interphase Nucleus

The nucleus of the cell which is not in the process of division is called interphase nucleus.

Robert Brown first noticed the largest organelle, the nucleus. It is present in all eukaryotic cells except RBC. Cells usually have one nucleus (mononucleate), but some cells may be binucleate or polynucleate.

Cell Unit Of Life Structural Organization Structure Of Nucleus

It may be placed in the centre or one side of the cell. It is mostly spherical or oval in shape or it may be elongated or even lobulated. The size of the nucleus depends upon its proteins and DNA contents.

The cytoplasmic and nuclear masses remain in the state of equilibrium known as endoplasmic or kanophismic index (NP or KPL)

\(\mathrm{NP}=\frac{\text { Volume of nucleus }}{\text { Volume of cell }- \text { Volume of nucleus }}\) \(=\frac{\text { Volume of Nucleus }}{\text { Volume of eytoplasm }}\)

Nuclear envelope. The nucleus is bounded externally by a double membrane, the nuclear membrane, which beats sub-microscopic pores and through these pores it is in continuation with the membranes of the endoplasmic reticulum.

The space between the two nuclear membranes is called the perinuclear space. Each membrane is 75 A in diameter and perinuclear space is 150-350 A wide.

In structure and function, the nuclear membrane resembles the cell membrane. It disappears during cell division and is redeveloped tram the membrane of the endoplasmic reticulum. Internally, the nucleus is filled with a viscous fluid, the nuclear sap. nucleoplasm or karyolymph. It is rich in protein and contains nucleic acid.

Nucleolus. (PI. Nucleoli Fontana 1784, discovered which was described by Wagner (1840) and Bowman (1S40) provided the present name. Nucleolus is an irregularly shaped often dense and compact body. It consists of protein and RNA. The patient forms SOT of the dry weight of the nucleolus. The nucleolus performs three functions, synthesis of proteins.

Mitochondria And Chloroplasts Roles NEET Exam Preparation

synthesis of ribosomal RNA and transfer of genetic information from the nucleus to the cytoplasm. It is interesting to note that the nucleolus disappears during cell division. Chromatin material or network is a granular mass which lies in the nucleoplasm.

The chromatin with fine threads is called euchromatin. The chromatin material consists of DNA. RNA. histone and acidic protein. During cell division, the chromatin material organizes itself and becomes distinct as chromosomes.

Differences Between Euchromatin And Heterochromatin

Cell Unit Of Life Structural Organization Difference Between Euchromatin

Nuclear functions. Robert Brown (1831) discovered the nucleus which was later mentioned as store storehouse of heredity information. Van Benedan and Hertwig demonstrated the role of the nucleus during the fusion of male and female gametes.

Boveri (1889) experimented with sea urchin eggs and established that survival, growth and reproduction are controlled by the nucleus.

Hammerling’s (1913) grafting experiment with Acetabularia Mediterranean proved that morphology is governed by the nucleus.

Hofmeister observed chromatin threads during cell division. Sutton and Boveri observed parallel behaviour between chromosomes and genetic characters and proposed the chromosome theory of heredity.

The DNA constituents of the nucleus act as the chemical basis of genetics. Structure of chromosome.

The chromatin network undergoes condensation, and coiling and is transformed into a definite rod-shaped structure of the chromosome. The chromosomes were discovered first by Hofmeister and the word chromosome was given by Waldeyer (1888).

A typical chromosome has the following parts:

Pellicle. It is the outermost covering membrane chromosome. However, Ris (1945) denies the presence of pellicles.

Matrix. It is the ground substance of chromosomes and contains a chromatin network.

Chromonema. There are two spirally coiled threads in the matrix, known as chromonemata. They are seen throughout the length of the chromosome. Each chromonema is 800 A in thickness and consists of one molecule.

Chromoniercs. These are dot-like or hcad-like structures of chromonema which have coiled up in specific ways to form complex and dense chromatin, the chroinomcres.

Mitochondria And Chloroplasts Roles NEET Exam Preparation

Centromere. It is situated in the region of primary constriction. In this region, the two chromonema join to form one.

The position of the centromere helps in the identification of chromosomes. According to the position of the centromere the chromosomes are of four types: metacentric, submetacentric, acrocentric and telocentric.

According to the number and presence or absence of centromeres, chromosomes arc of the following types:

Acentric (without centromere), monocentric, dicentric and polycentric with one, two or many centromeres.

Secondary Constriction. This constriction may be present in one or both arms of the chromosomes. This is the place where a nucleolus appears and disappears during the cell cycle. Thus it is also known as the nucleolar organizing region.

Satellite. The distal spherical part of chromosome above sec. constriction is known as a satellite. The chromosomes having satellite arc are known as SAT-chromosomes where SAT stands for Sine Acid Thymunucleinico.

Telomere. Each chromosome has polarity. Its terminal ends are physiologically different from the rest of the chromosomes and are known as telomeres. They avoid sticking of chromosomes in the nucleus. If by X-rays these ends arc broken, then one chromosome will stick to another chromosome.

In chromosomes, DNA and histones arc bonded to form dcoxyri bonuclcoprotcin. The most accepted model for the arrangement of DNA and histone protein is the nucleosome or sole noid model (Woodcock).

The term nucleosome was given by. Outlet ( 1 975). To accommodate the nucleosome model for DNA, Crick and Watson proposed the Kinky helix model for DNA. A nucleosome is a repeating unit of chromatin (125 nm is diameter = 200 base pairs + 2 molecules each of H2A, H2B, H3 and H4)

Lampbrusli Chromosomes. Such chromosomes are found in the oocytes of amphibians and appear like a brush which was used in the olden times to clean street lamps. That is why, they are known as lampbrush chromosomes.

A lampbrush chromosome consists of a central main axis made up of DNA whereas the matrix which consists of RNA and protein is present in the form of a loop of the main axis. The loops lie opposite to each other.

Endoplasmic Reticulum Types And Functions NEET

Each loop consists of an axial fibre which is covered with a matrix. When it is treated with ribonucleases (an enzyme which breaks down DNA) it is broken down indicating that it consists of DNA.

When it is treated with ribonucleic (an enzyme which breaks down RNA), trypsin and pepsin the matrix of the loop is removed. From that, it can be concluded that the matrix is composed of RNA and protein whereas the axial fibre of DNA.

Polytene Chromosomes. They were first observed by Italbiani (1881) in the salivary gland of Chirommous and hence sometimes are also known as salivary gland chromosomes.

They are also found in Drosophila. In Chironomus, usually, one somatic cell consists of 8 polytene chromosomes. They measure 1000 times larger than normal chromosomes. They are 2,000 Im in length.

A polytene chromosome consists of several parallel strands, chromonema. The coils containing polytene chromosomes continue to grow without undergoing mitosis. One chromosome may have as many as 1024 chromonemata. All strands are genetically identical.

  • m-chromosomes. Minute-sized (less than 0.5 mm) chromosomes are found in many bryophytes. and insects.
  • Chemically, Chromosomc is formed of 40% DNA, 50% histones, 1.5% RNA, etc. H, H2A and Hyn proteins are lysine-rich (2 is very lysine-rich) while H3 and H4 are arginine >ric)i polypeptide chains.
  • Satellite is also called Trabant.
  • NOR constitutes 03% of total nuclear DNA. NOR is also called secondary constriction I.
  • Muller (1938). Coined the term telomeres.
  • Vejdovsky (1912). Coined the term chromonema.
  • Du Praw : (1966). Proposed uncinematic folded fibre model of the chromosome.
  • Finch and Klug (1976). Proposed solenoid model. It states that DNA is associated with histone proteins to form a series of beads called nucleosomes.
  • Nucleosomes: Fundamental packing unit of chromonema.

NEET Biology Cell Unit Of Life Cell Inclusions

Reserve food. It may be in the form of starch grains (Example in potato-tuber cells) or glycogen granules (Example in liver and muscle cells of animals), protein granules (Example in aleuroplasts of the endosperm of maize seed), or oil droplets (Example in adipocytes of fat bodies; endospermic cells of castor and coconut and in cotyledon cells of groundnut and mustard seeds).

Gases. These include O2, CO2, N2 etc.

Inorganic crystals. These include crystals of calcium salts and silica. Silica is generally found in the epidermal cells of grasses. Crystals of calcium carbonate, called cystoliths, are found in the epidermal cells of Mimordica (Kerala), while crystals of calcium oxalate are called raphides and are found in the epidermal cells of Eichhomia (water hyacinth). Hyaloplasm also contains organic acids like tartaric acid (In tamarind), citric acid (citrus fruits) and malic acid (as in apples).

Excretory/Secretory Products. They include mucus, tannins, resins, gums, alkaloids, latex, etc.

Latex. It is a crystallo-colloid fluid secreted by latex tubes or Iaticifers of two types, latex cells (non-articulated Iaticifers, Example Banyan, Calotropis, Oleander) and latex vessels (articulated Iaticifers, Example Poppy, Rubber plant, Sonchus). Latex can be watery (For example Banana), milky (For example Banyan) or coloured (For example Poppy).

The latex of Hevea brasiliensis yields rubber, that of Poppy forms opium while the latex of Papaya contains the protein-digesting enzyme papain,

Gums. They are degradation products of cell walls, for example, gum Arabic (Acacia Senegal).

Gum-Resin. It is mixture of gum and resin, Example root of Ferula asafoetida (asafoetida).

Resins. They are acidic oxidation products of essential oils which are insoluble in water but soluble in alcohol/ turpentine. An example of hard resin is shellac. Pine resin and Canada Balsam are oleo-resins (resins with associated essential oils).

Endoplasmic Reticulum Types And Functions NEET

Tannins. They are astringent, acidic, phenolic compounds, related to glucosides, found in leaves (For example Tea), bark (For example Acacia nilotica, Walnut or Juglans regia) fruit (For example Caesalpinia, Betel Nut), Dyes related to tannins are cutch (heartwood of Acacia catechu), and haematoxylin (heartwood of Haematoxylon).

Alkaloids. They are bitter nitrogenous by-products, often poisonous and with medicinal properties, Example quinine (bark of Cinchona officinalis), atropine (leaves and tops of Atropa belladonna), nicotine (leaves of Nicotiana tabacum (tobacco), morphine (latex of Papaver somniferum (poppy), reserpine (roots of Rauwolfia serpentina), colchicine (corms of Colchicum autumnale), thein (Tea leaves),

Glucosides present is crucifers. They are aromatic compounds having glucose/carbohydrates, for example, saponin, digitoxin, digitalin, and amygdalin. Many of them are medicinal, (viii) Essential Oils. They are volatile aromatic oils secreted by special glands, Example Lavender, Rosemary oil, Menthol, Eucalyptus oil,

Nectar. It is the sugary secretion of parts of flowers to attract insects and other animals for pollination. Nectar contains glucose,’ fructose and sucrose.

Pigments. These are found in special cells, called chromatophores, present in the skin (dermis) of vertebrates (fishes, amphibians and reptiles).

The chromatophores are of two types: melanophores have brown or black pigment, and lipophores contain red, yellow and orange pigments. Birds and mammals have a pigment in their feathers and hair. In the human skin, the pigment-containing cells occur in the deeper epidermal cells

  • Prokaryotic cells are represented by bacteria, blue-green, algae, mycoplasma or PPLO, spirochaete and rickettsiae generally smaller than eukaryotic cells but multiply more rapidly.
  • The bacterial flagellum is formed of filament, hook and basal body which is a hollow rigid, cylindrical filament longest (1-70 nm), formed of flagellin protein.
  • The basal body of the bacterial flagellum is a complex part of the flagellum, consisting of four and two rings connected to the central rod in Gram-ve and Gram+ve bacteria respectively.
  • The filament, hook and basal body are arranged in such a manner to permit the filament to rotate by 360° rather than undulating back and forth like a whip. In the plasma membrane of eukaryotic cells sterol molecules are more rigid than phospholipids and therefore the presence of sterol confers stability on each eukaryotic membrane.
  • Three principal types of protein filament-microfilaments (7nm), microtubules (25nm) and intermediate filaments (8-10nm) are cytoskeletal elements which allow the eu¬ karyotic cell to adopt a variety of shapes and carry out directed movements.
  • In Golgi bodies, materials are transported from the cis to the trans face by vesicles that keep budding off from the cisternal edge to the next cell and so on.
  • The sequence of the size of the organelles is as follows:
  • Lysosome(0-2-0-8pm) <Sphaerosome (0-5-1 -0pm) < Per peroxisome (0-5- M pm)< Ribosome (l-5-2-0pm)
  • Pinosomes and phagosomes are collectively known as endosomes.
  • The vacuoles of plant cells are bounded by a single semipermeable membrane called tonoplast, whereas the vacuoles, of animal cells are by, a lipoprotein membrane.
  • Vacuoles are of four types depending upon function t. sap vacuoles, contractile vacuoles, food vacuoles and air, rapidly.
  • vacuoles/ The proper folding of proteins following synthesis is assisted by a special protein called chaperones.
  • Mitochondria can be seen in inactive or orthodox state and active or condensed state.
  • Both mitochondrial (mt DNA) and chloroplast DNA (cp DNA) containing limited genetic information are circular although cp DNA is much bigger than mt DNA
  • The amount of DNA is low in a chloroplast i.e. 10-15 to 10y grams per chloroplast or 0-03% of its dry weight.
  • Cilia and flagella having a 9+2 arrangement are associated with the motility of cells.
  • Karyotype. The arrangement of chromosomes in terms of their relative size, form and number is called karyotype. It consists of the arm ratio and position of the centromere also. It is characteristic of a species.
  • Karyotype preparation can be done by either banding technique or fluorescence in situ hybridisation (FISH) and multicolour fluorescence in situ hybridisation (FISH) or Flow cytometry.
  • Idiogram. A pencil sketch or photograph of the karyotype is called idiogram.
  • Human Karyotype. Somatic cells contain a total of 46 chromosomes (Tijio and Levan 1956) or 23 pairs.
  • Out of these 22 pairs are autosomes, one pair of sex chromosomes XX in females (homomorphic) and XY in males (heteromorphic).

Quanta to memory

  • The term ‘cell’’ coined by Hooke (1665), is; a misnomer as the cell is not a hollow structure.
  • Cytoplasm coagulates at temperatures above 60° C.
  • Swammerdam was the first to describe the cell (RBC of frog).
  • Largest cell—Egg of ostrich (6 inches in diameter with shell and 3″ without shell.)
  • The nerve cell is the longest in the human body. The smallest cell (Mycoplasma gallisepticum—PPLO) measures 0.1 to 0.3 pm. Unicellular eukaryotes are 1 to 1000. pip in size. The size of human RBC is 7-8 pm.
  • Cells of multicellular eukaryotes are 5 to 1000 pm in size.
  • Fibre of Boehmeria (longest plant cell is 55 cm in size).
  • PPLO (Mycoplasma Lauderhill) are also called “Jokers
    of plant kingdom.
  • Transosome organelles are bounded by triple membranes.
  • Organelles without membranes are ribosomes, centrioles,
    microfilaments and microtubules
  • In human beings, cells of the kidney are the smallest and of nerve fibres largest.
  • The size of human RBC is 7-8 pm.
  • Cells of multicellular eukaryotes is 5 to 1000 pm in
    size.
  • Fibre ofBoehmeria (longest plant cell is 55 cm in size). PPLO (Mycoplasma laiderwili) are also called “Jokers of the plant kingdom.”
  • Transosome organelles are bounded by triple membranes. Organelles without membrane are ribosomes, centrioles, microfilaments and microtubules.
  • In human beings, the cells of the kidney are the smallest and of nerve fibre largest.
  • Intracellular compartments in cells help in the efficient functioning of cells.
  • A pyrenoid is a proteinaceous body around which starch is stored in green algae.
  • Protochlorophyll differs from chlorophyll in lacking 2 hydrogen atoms in two of its pyrrole units.
  • Microtubules are involved in cell division.
  • Two genome types are present in typical green plants.
  • Basophilic ergastroplasm indicates the presence of ribosomes.
  • Chromosomes are stained with acetocarmine processing or Acid Fuschia.
  • Bioblast = Mitochondrion = Bioplast = unit of protoplasm capable of reproducing itself.
  • The cell wall is capable of growth and is involved in many enzymatic activities, so is now considered as a living structure.
  • A ripened fruit becomes soft because the pectates of the middle lamella solubilize on ripening.
  • Myeloid bodies (granules at the base of retinal pigment cells) and Nissl granules (in the cyton of neurons) are RER (ER with ribosomes).
  • Svedberg Unit (S). It is the rate of sedimentation or velocity of sedimenting the particles per unit of gravitational force, or lx 10-13 cm /sec/dyne/gm.
  • The largest component of the cell is the nucleus while the smallest component is the microfilament.
  • The largest cell organelle is the mitochondrion in animal cells and plastid in plant cells while the smallest cell organelle is the ribosome.
  • The darkly staining property of chromatin is called heteropykinosis.
  • Mitoribosomes of mammals have a sedimentation coefficient of 55 S.
  • Smallest Human Cell. Erythrocytes with a diameter of 6-8 pm. Blood platelets are still smaller (2-3 pm in diameter) but they are considered to be cell fragments instead of cells themselves. (Malarial sporozoite is 2 pm in length).
  • Coconut milk is widely used in tissue culture as it is rich in a kind of growth hormone named cytokinin.
  • Callus and Cancer both are undifferentiated masses of cells.
  • But calluses get differentiated into root and shoot by auxins and cytokinins in tissue culture and cancer cells fail to differentiate in tissue culture.
  • The explant is an excised plant part used in tissue culture to
    raise Callus.
  • Animal Cloning. Animal cells are totipotent like plant cells but there is difficulty in their dedifferentiation and later differentiation.
  • Animal cloning has become possible by inserting the nucleus of a somatic cell into an enucleated egg and allowing the latter to develop into the uterus of a female. The first successfully cloned animal is Dolly, a sheep (1996—1997)

Cell Unit Of Life Structural Organization Structure Of Cell

Cell The Unit of Life for NEET MCQs

by

NEET Biology Cell Unit Of Lift And Structural Organization MCQs

Question 1. The part/parts of a cell that can be seen with an electron microscope, but never with a light microscope is/are the:

  1. Nucleus
  2. Golgi bodies
  3. Chloroplasts
  4. The membrane separates the nucleus from the cytoplasm.

Answer: 4. Membrane separating the nucleus from the cytoplasm.

Question 2. Fundamentally a dead cell differs from a living cell because:

  1. It has become separated from other cells
  2. Its vital forces have been destroyed
  3. A change in its surrounding environment has occurred
  4. A change in its specific organization has occurred.

Answer: 2. A change in its surrounding environment has occurred

Question 3. Plant cell differs from animal cells by :

  1. Cell wall absent in animal cell but chloroplast present
  2. Cell wall and chloroplast absent in animal cell
  3. Vacuoles only a few and that too contractile are present in plant cell
  4. Cell walls are present in an animal cells.

Answer: 2. Cell wall and chloroplast absent in animal cell

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 4. The organic molecules present in traces in living cells can be detected and isolated by:

  1. Centrifugation
  2. Tracer technique
  3. Chromatography
  4. Microscopy.

Answer: 3. Chromatography

Cell The Unit of Life Botany NEET MCQQuestion 5. The cell theory was proposed by :

  1. Robert Hooke
  2. Leuwenhoek
  3. Schleiden and schwann
  4. Purkinje.

Answer: 3. Schleiden and schwann

Cell The Unit of Life for NEET MCQs

Question 6. 1 A is equal to:

  1. 10 8 Cm
  2. 10Acm
  3. 10-6 Cm
  4. 10 3 Cm.

Answer: 1. 10 8 Cm

Question 7. Which of the following sets resemble in their basic structure and function:

  1. Centrioles, cilia and flagella
  2. DNA, MRNA And TRNA
  3. Er, Golgi complex and lysosome
  4. Leucoplast, chloroplast and chromoplasts.

Answer: 1. Centrioles, cilia and flagella

Question 8. How many membranes comprise the nuclear envelope?

  1. One
  2. Two
  3. Three
  4. None.

Answer: 2. Two

Question 9. Which of the following organelles regularly moves from the nucleus to the cytoplasm?

  1. Glycogen
  2. Cholesterol
  3. RNA
  4. DNA.

Answer: 3. RNA

Cell The Unit of Life Botany NEET MCQ Question 10. Which of the following cellular organelles breaks down complex macromolecules such as polysaccharides and proteins?

  1. Golgi complex
  2. Lysosome
  3. Mitochondria
  4. Rough endoplasmic reticulum.

Answer: 2. Lysosome

Question 11. The fuel gen reaction of dna is due to :

  1. Aldehyde produced by acid hydrolysis
  2. Removal of RNA but not dna
  3. Phosphoric acid, carbohydrates and nitrogen bases
  4. Phosphoric acid.

Answer: 1. Aldehyde produced by acid hydrolysis

Question 12. Which one of the following does not lose living nature even after crystallization?

  1. Protista
  2. Bacteria
  3. Viruses
  4. Parazoa.

Answer: 3. Viruses

Question 13. In prokaryotic cells, the enzymes involved in the oxidation of metabolites is associated with :

  1. Nucleoid
  2. Plasma membrane
  3. Ribosomes
  4. Plasmosome.

Answer: 2. Plasma membrane

Question 14. Which of the following is an exception to cell theory?

  1. Bacteria
  2. Protozoans
  3. Protista
  4. Viruses.

Answer: 2. Protozoans

Cell The Unit Of Life MCQ For NEET Biology With Answers Question 15. Which of the following relationships between cell structure and their respective function is not correct?

  1. Cell wall – support, protection
  2. Cilia – site for diffusion
  3. Chromosome – carrier of heredity material
  4. Mitochondria – a powerhouse of cell1.

Answer: 4. Mitochondria – powerhouse of cel1.

Question 16. A human egg is very large compared to a human sperm. Most of this size differential is due to the difference in their:

  1. Nucleus
  2. Membranes
  3. Cytoplasm
  4. Both 1 and 3.

Answer: 3. Cytoplasm

Question 17. The cortex of the human brain may consist of :

  1. Six billion, two hundred million cells
  2. Seven billion, two hundred million cells
  3. Eight billion, two hundred million cells
  4. Nine billion, two hundred million cells.

Answer: 2. Seven billion, two hundred million cells

Question 18. The human body weighs about 50 kg. May consist of:

  1. 25 X 1015 cells
  2. 50 X 101s cells
  3. 100 X 101s cells
  4. 150 X 101s cells.

Answer: 4. 150 X 101s cells.

Question 19. Nucleoli are rich in :

  1. Ribose nucleic acid
  2. Deoxyribose nucleic acid
  3. Proteins and RNA
  4. Carbohydrates.

Answer: 3. Proteins and RNA

Question 20. Which of the following phenomena is not found in viruses in the host cell?

  1. Replication
  2. Production of energy
  3. Mutation
  4. None of the above.

Answer: 2. Production of energy

Question 21. The correct order of sedimentation of subcellular structures during differential centrifugation is as follows:

  1. Lysosome -+ mitochondria -+ nucleus -l ribosome
  2. Mitochondria-+ nucleus -+ lysosome -+ ribosome
  3. Nucleus -+ mitochondria->lysosome + ribosome
  4. Lysosome -+ ribosome-+ mitochondria –> nucleus.

Answer: 3. Nucleus -+ mitochondria->lysosome + ribosome

Cell The Unit Of Life MCQ For NEET Biology With Answers Question 22. Which of the following represents the correct sequence of relative sizes in descending order?

  1. Cell, nucleus, chromosome, water molecule, oxygen atom
  2. Cell, nucleus, water molecule, oxygen atom, chromosome
  3. Chromosome, cell, nucleus, water molecule, an oxygen atom
  4. Cell, nucleus, water molecule, chromosome, oxygen atom.

Answer: 1. Cell, nucleus, chromosome, water molecule, oxygen atom.

Question 23. The activities of all living cells are controlled by :

  1. Chloroplasts
  2. Auxins
  3. Nucleus
  4. Tonoplast.

Answer: 3. Nucleus

Question 24. Leaf pigments are separated from a mixture by :

  1. Spectrophotometry
  2. Autoradiography
  3. Chromatography
  4. Microcinematography.

Answer: 3. Chromatography

Question 25. Which of the following sets of cell organelles contains dna?

  1. Mitochondria, ribosomes and chloroplasts
  2. Nucleus, ribosomes and chloroplasts
  3. Nucleus, ribosomes and mitochondria
  4. Nucleus, mitochondria and chloroplasts.

Answer: 4. Nucleus, mitochondria and chloroplasts.

Question 26. Leaving aside water, which of the following constitutes the bulk of an active living cell?

  1. Ribose nucleic acid
  2. Deoxyribose nucleic acid
  3. Proteins
  4. Carbohydrates.

Answer: 3. Proteins

Cell The Unit Of Life MCQ For NEET Biology With Answers Question 27. Which one of the following is incorrect?

  1. All cells do not contain a true nucleus
  2. All living plant cells contain chlorophyll
  3. Cell rivals are generally made up of cellulose
  4. Respiration occurs in mitochondria.

Answer: 2. All living plant cells contain chlorophyll

Question 28. The endoplasmic reticulum often contains :

  1. Ribosomes
  2. Golgi bodies
  3. Centrioles
  4. Lysosomes.

Answer: 1. Ribosomes

Question 29. The fine network of membranes distributed extensively throughout the cytoplasm in a cell is referred to as:

  1. Golgi bodies
  2. Peroxisome
  3. Lysosome
  4. Endoplasmic reticulum.

Answer: 4. Endoplasmic reticulum.

Question 30. The endoplasmic reticulum occurs in the form of:

  1. Cisternae only
  2. Vesicles only
  3. Tubules only
  4. All the above.

Answer: 4. All the above.

Question 31. The endoplasmic reticulum in the cells of adipose tissue is in the form of:

  1. Vacuoles
  2. Sacs
  3. Tubules
  4. All the above.

Answer: 1. Vacuoles

Cell The Unit Of Life MCQ For NEET Biology With Answers Question 32. When the region of the endoplasmic reticulum is studded with ribosomes on the outer surface of the cisternae. It is called:

  1. Sarcoplasmic reticulum
  2. Smooth endoplasmic reticulum
  3. Granular endoplasmic reticulum
  4. None of the above.

Answer: 3. Granular endoplasmic reticulum

Question 33. The principal site of the synthesis of ribosomal RNA is the :

  1. Mitochondria
  2. Golgi bodies
  3. Nucleolus
  4. Lysosomes.

Answer: 3. Nucleolus

Question 34. During active protein synthesis, some ribosomes seem to occur in groups and are collectively known as :

  1. Bound ribosomes
  2. Polyribosomes
  3. Lysosomes
  4. Dictyosomes.

Answer: 2. Polyribosomes

NEET Biology MCQ Cell The Unit of Life Question 35. Ribosomes are present in the cytoplasm as minute particles:

  1. Associated with er and are sites for protein synthesis
  2. Associated with mitochondria are the sites of glucose oxidation
  3. On the cell surface and are concerned with protein synthesis
  4. None of the above.

Answer: 1. Associated with er and are sites for protein synthesis

Question 36. Which of the following are prokaryotes?

  1. Viruses and rickets
  2. Bacteria and archaebacteria
  3. Cyanobacteria and mycoplasma
  4. Both 2 and 3.

Answer: 4. Both 2 and 3.

Question 37. Ribosomes originate from:

  1. Nucleus
  2. Er
  3. Nucleolus
  4. Mitochondria.

Answer: 3. Nucleolus

Question 38. Ribosomes present in a prokaryotic cell are :

  1. 70 S type
  2. 60 S type
  3. 80 s type
  4. Both 70s and 80s type.

Answer: 1. 70 S type

Question 39. Sphaerosomes have an affinity for :

  1. Sudan black
  2. Eosin stains
  3. I Leishman’s stain
  4. Giemso’s stain.

Answer: 1. Sudan black

NEET Biology MCQ Cell The Unit of Life Question 40. Ribosomes are :

  1. Positively charged
  2. Negatively charged
  3. Amphoteric
  4. None of the above.

Answer: 2. Negatively charged

Question 41. Golgi apparatus is present in :

  1. Phanerogams
  2. Cryptogams
  3. All eukaryotes
  4. Vertebrates.

Answer: 3. Vertebrates.

Question 42. Dictyosome is also known as :

  1. Respiratory particle
  2. Ribosome
  3. Golgi bodies
  4. Peroxisome.

Answer: 3. Peroxisome.

Question 43. Golgi bodies are related to:

  1. Excretion
  2. Energy liberation
  3. Pinocytosis
  4. Secretions.

Answer: 3. Pinocytosis

Question 44. Golgi bodies are maximum in :

  1. Calyptrogen
  2. Root cap
  3. Both 1 and 2.
  4. Root tip.

Answer: 4. Root tip.

NEET Biology MCQ Cell The Unit of Life Question 45. Which of the following cell organelles are considered to be rich in catabolic enzymes?

  1. Endoplasmic reticulum
  2. Lysosomes
  3. Golgi bodies
  4. Mitochondria.

Answer: 2. Lysosomes

Question 46. Which of the following is widely distributed in a cell?

  1. Chromoplasts
  2. Chloroplast
  3. RNA
  4. DNA.

Answer: 3. RNA

Question 47. Membranes are found within :

  1. Chromosomes, nuclei and mitochondria
  2. Cytoplasm, chloroplasts and mitochondria
  3. Cytoplasm, nuclei and starch grains
  4. Chromosomes, chloroplasts and starch grains.

Answer: 2. Cytoplasm, chloroplasts and mitochondria

Question 48. Most of the hydrolytic enzymes of lysosomes function at :

  1. Acidic ph (ph =5)
  2. Basic ph
  3. Neutral ph
  4. Any ph.

Answer: 1. Acidic ph (ph =5)

Question 49. The secretory material is discharged by the Golgi vesicles, from the surface of the cell membrane by:

  1. Pinocytosis
  2. Endocytosis
  3. Reverse pinocytosis
  4. Dissolving the cell membrane.

Answer: 3. Reverse pinocytosis

NEET Biology MCQ Cell The Unit of Life Question 50. Mitochondrial DNA differs from nuclear DNA in:

  1. Being linear
  2. Having a=tandc: g
  3. Being highly twisted
  4. Lacking binding with the histones.

Answer: 4. Lacking binding with the histones.

Question 51. In the nucleon ema of the nucleus, particles 150- 2004 are seen which resemble:

  1. Ribosomes
  2. Lysosomes
  3. Mitochondria
  4. Sphaerosomes.

Answer: 1. Ribosomes

Question 52. Mitochondria can be distinguished from similar-looking particles in living cells by their affinity for a dye called:

  1. Acetocarmine
  2. Janus green.
  3. Eosin
  4. Methylene blue.

Answer: 2. Janus green

Question 53. Which of the following observations most strongly support the view that mitochondria contain electron transfer enzymes aggregated into compact association?

  1. Mitochondria have a highly folded inner wall
  2. Disruption of mitochondria yields membrane fragments which can synthesize ATP
  3. Mitochondria in animal embryos tend to concentrate in cells which become a part of the locomotory structure
  4. A contractile protein capable of utilising ATP has been obtained from mitochondria.

Answer: 2. Disruption of mitochondria yields membrane fragments which can synthesize atp

Question 54. Within the cell, the site of respiration is:

  1. Nucleus
  2. Mitochondrion
  3. Ribosome
  4. Lysosome.

Answer: 4. Lysosome.

NEET Biology MCQ Cell The Unit of Life Question 55. Cristae refer to :

  1. Infolding of the inner membrane of mitochondria
  2. Infolding of the outer membrane of mitochondria
  3. Branches of endoplasmic reticulum
  4. Golgi apparatus.

Answer: 1. Infolding of the inner membrane of mitochondria

Question 56. A mitochondrion possesses a :

  1. Single membrane
  2. Double membrane
  3. Three-layered membrane
  4. Four-layered membrane.

Answer: 2. Double membrane

Question 57. The existing evidence favours that mitochondria arise;

  1. From precursors in the cytoplasm
  2. From non-mitochondrial membranes
  3. By growth and division of pre-existing mitochondria
  4. None of the above.

Answer: 3. None of the above.

Question 58. The Golgi apparatus present in cells synthesizes:

  1. Cellulose
  2. Hemicellulose
  3. Pectin
  4. All of the above.

Answer: 4. All of the above.

Question 59. The Golgi apparatus is bounded by :

  1. Single unit membrane
  2. Cellulose layer
  3. Plasma membrane
  4. The double unit membrane of lipoproteins.

Answer: 1. Single-unit membrane

NEET Biology MCQ Cell The Unit of LifeQuestion 60. Which one of the following is responsible for the breakdown of parts of the cell and foreign particles in the cell?

  1. Ribosome
  2. Centrosome
  3. Lysosome
  4. Golgi apparatus.

Answer: 3. Lysosome

Question 61. The percentage of mitochondrial dna in the cells is:

  1. 10% Of total cellular dna
  2. L% of total cellular dna
  3. 2.5% of total cellular dna
  4. None of the above.

Answer: 2. L% of total cellular dna

Question 62. Secondary lysosomes give rise to:

  1. Residual bodies
  2. Tertiary lysosomes
  3. Peroxisome
  4. None of the above.

Answer: 1. Residual bodies

Question 63. Lysosomes are considered suicidal bags because they:

  1. Kill the neighbouring cells
  2. Kin the engulfed bacteria
  3. Are responsible for intracellular digestion
  4. Oxidise the food in the cells.

Answer: 3. Are responsible for intracellular digestion

Question 64. Lysosome along with the food contents is :

  1. Primary lysosome
  2. Secondary lysosome
  3. Residual bodies
  4. Cytosome.

Answer: 2. Secondary lysosome

Question 65. Peroxisomes are bounded by :

  1. Single membrane
  2. Double membrane
  3. Triple membrane
  4. No membrane.

Answer: 1. Single membrane

Question 66. Peroxisomes do not have :

  1. O-amino acid oxidase
  2. B-hydroxy acid oxidase
  3. Urate oxidase
  4. DNA synthetase.

Answer: 4. Dna synthetase.

Question 67. Bone cells containing lysosomes are:

  1. Osteofibrils
  2. Osteoclasts
  3. Osteoblasts
  4. None of the above.

Answer: 2. Osteoclasts

Question 68. Sphaerosomes arise from;

  1. Mitochondrion
  2. Lysosome
  3. E.r.
  4. Ribosome.

Answer: 3. E.r.

Question 69. Sphaerosomes are mostly present in :

  1. All cells
  2. Prokaryotic cells
  3. Lipid secreting and storing cells.
  4. None of the above.

Answer: 3. Lipid secreting and storing cells.

Question 70. The cellular role of the lysosome is not :

  1. Ingestion of foreign bodies
  2. Digestion of aged organelles
  3. Cell destruction during development
  4. Osmoregu location.

Answer: 4. Osmoregu lation.

Question 71. The first scientist to say that plants purify air in the presence of light was:

  1. Van Belmont
  2. Priestley
  3. Ingenhousz
  4. Blackman.

Answer: 3. Ingenhousz

Question 72. Thylakoids are presenl in plasrids of :

  1. Bacteria
  2. Cyanobacteria
  3. Higher plants
  4. All the above.

Answer: 3. Higher plants

Question 73. The main types of plastids meant for photosynthesis are:

  1. Leucoplasts
  2. Chromoplasts
  3. Chloroplasts
  4. None of them.

Answer: 3. Chloroplasts

Question 74. Isolated chloroplasts can synthesize :

  1. RNA
  2. DNA
  3. Proteins
  4. None of the above.

Answer: 4. None of the above.

Question 75. Dna genetic material occurs by itself in lower organisms and is combined with proteins as nucleoproteins in higher organisms. The nucleoprotein is organized in higher looms to form:

  1. Chromosome
  2. Nucleolus
  3. Nucleotides
  4. Nucleoside.

Answer: 1. Chromosome

Question 76. The nucleus was first discovered by :

  1. Walson and crick
  2. Bowman
  3. Roberr brown hooke.
  4. Hooke

Answer: 3. Roberr brown hooked.

Question 77. A nucleus which involves the duplication of chromosomes but fails to divide is known as :

  1. Endomitosis
  2. Restitution nucleus
  3. Euploidy
  4. Polyploidy.

Answer: 2. Restitution nucleus

Question 78. Which stain gives purple or violet colour to the chromosome?

  1. Feulgen
  2. Acetocarmine
  3. Acetocein
  4. Safranin.

Answer: 1. Feulgen

Question 79. The structure of the nuclear membrane facilitates:

  1. Organization of spindle
  2. Synapsis of homologous chromosomes during meiosis
  3. Nucleo-cytoplasmic exchange of materials
  4. Anaphasic separation of daughter chromosomes.

Answer: 3. Nucleo-cytoplasmic exchange of materials

Question 80. The pores of the nuclear membrane have a diameter of :

  1. 400Å to 1000Å
  2. 600Å to 900Å
  3. 100Å to 200Å
  4. 700Å to 760Å

Answer: 4. 700Å to 760Å

Question 81. If the nucleus represents its large size in proportion to the cytoplasm of the cell, it indicates that:

  1. The cell is dying
  2. The nucleus is in the resting phase
  3. The nucleus has entered the s-phase of the interphase
  4. The cell is about to die.

Answer: 3. The nucleus has entered the s-phase of the interphase

Question 82. An acentric chromosome at metaphase will be :

  1. Condensed and lie near the equator
  2. Irregularly shaped and lying at one of the poles
  3. Condensed and lie at poles
  4. Coiled and attached to spindle fibre.

Answer: 1. Condensed and lie near the equator

Question 83. Cytochromes present in the cells are :

  1. Electron acceptors
  2. Carbon acceptors
  3. Hydrogen acceptors
  4. Nitrogen acceptors.

Answer: 1. Electron acceptors

Question 84. The parallel layering of membranes in chloroplast is suited for:

  1. Maximum light absorption
  2. Maximum exposure to enzymes
  3. Minimum light absorption so that the cells can maintain their temperature
  4. All the above.

Answer: 1. Maximum light absorption

Question 85. Non-photosynthetic plastids are :

  1. Amyloplasts
  2. Chromoplasts
  3. Chloroplasts
  4. Both 1 and 2.

Answer: 4. Both 1 and 2.

Question 86. The organelles which occur outer to the cell membrane but inner to the cell wall are :

  1. Sphaerosomes
  2. Lomasomes
  3. Glyoxisomes
  4. Peroxisomes.

Answer: 2. Lomasomes

Question 87. Centrioles are :

  1. Cylindrical structures
  2. Rectangular structures
  3. Cuboidal structures
  4. Square structures.

Answer: 1. Cylindrical structures

Question 88. The fruits on ripening become coloured, it is due to the:

  1. Disintegration of chloroplasts and development of chromoplasts
  2. Conversion of chloroplasts to chromoplasts
  3. Conversion of chlorophyll into anthocyanin pigment
  4. All the above.

Answer: 1. Disintegration of chloroplasts and development of chromoplasts

Question 89. Mitochondria and chloroplasts are believed to be bacterial endosymbionts of cells because:

  1. They have their nucleic acids
  2. Their inner membrane resembles those of bacteria
  3. They do not arise de novo
  4. They have all the above attributes.

Answer: 4. They have all the above attributes.

Question 90. Which of the following shows a 9 + 0 arrangement?

  1. Centriole
  2. Cilia
  3. Cilia + centriole
  4. Cilia + centriole + flagellum.

Answer: 1. Centriole

Question 91. Cilia and flagella are responsible for :

  1. Respiration
  2. Locomotion
  3. Co-ordination
  4. Lipid formation.

Answer: 2. Locomotion

Question 92. Microfilaments are long. Thin fibres 40-60 a :

  1. Myosin
  2. Actin
  3. Tubulin
  4. Both 1 and 2.

Answer: 4. Both 1 and 2.

Question 93. The cellular role of the microtubule is not :

  1. Protein synthesis
  2. Int racell ulai communication
  3. Movement
  4. Formation of mitotic spindle.

Answer: 1. Protein synthesis

Question 94. One centriole is composed of:

  1. Nine triplet peripheral microtubules
  2. Nine doublet peripheral microtubules
  3. Nine singlet peripheral microtubules
  4. None of the above.

Answer: 1. Nine triplet peripheral microtubules

Question 95. Chromosomes having equal arms are known as :

  1. Metacentric
  2. Acrocentric
  3. Telocentric
  4. Acentric.

Answer: 1. Metacentric

Question 96. Prokaryotic flagella possess :

  1. A helically managed protein molecule
  2. Protein membrane-bound libres
  3. Unit membrane-enclosed fibre
  4. Microtubular “9 + 2” membrane-enclosed structure.

Answer: 1. Helically managed protein molecule

Question 97. The nucleolus is a :

  1. Distinct membrane-bound organelle
  2. Spheroid ribonucleoprotein only
  3. Parr of chromosome
  4. All of the above.

Answer: 2. Spheroid ribonucleoprotein only

Question 98. Perinuclear space is the space lying :

  1. Outside and around the nuclear membrane
  2. Inside and around the nuclear membrane
  3. Between the two nuclear membranes
  4. None of the above.

Answer: 3. Between the two nuclear membranes

Question 99. An October of four histones complexed with dna is called:

  1. Nucleosome
  2. Centrosome
  3. Chromosome
  4. Endosome.

Answer: 1. Nucleosome

Question 100. The core of nucleosome is made up of :

  1. H1.h2, a, h,b,h3
  2. H1,h2, a,h,b, h4
  3. H2 a, h2 b,h3,h1
  4. H2 a, h2 b,h3,h4

Answer: 4. H2 a, h2 b,h3,h4

Question 101. Nucleoli are not present in the cells of :

  1. Eukaryotes
  2. Blue-green algae
  3. Maize plant
  4. Pancreas.

Answer: 2. Blue-green algae

Question 102. Chromosomes can be specifically stained by :

  1. Safranin
  2. Acetocarmine
  3. Janus green
  4. Amine blue.

Answer: 2. Acetocarmine

Question 103. Mature mammalian white blood cells are :

  1. Without nuclei
  2. With four nuclei
  3. Without nucleoplasm
  4. With nuclei.

Answer: 4. With nuclei.

Question 104. The undifferentiated fibrillar nucleus is found in :

  1. Eukaryotes
  2. Cells of higher organisms
  3. Prokaryotes
  4. Higher animals.

Answer: 3. Prokaryotes

Question 105. Which of the following has a nucleus?

  1. Cork cell
  2. Sieve tubes
  3. Companion cell
  4. Vessels.

Answer: 3. Companion cell

Question 106. What will happen if the nucleus is removed?

  1. The metabolism will increase
  2. The cell will die
  3. The metabolism will decrease
  4. None of the above.

Answer: 2. The cell will die

Question 107. The process by which dna of the nucleus passes genetic information to mRNA is called :

  1. Translocation
  2. Transportation
  3. Translation
  4. Transcription.

Answer: 4. Transcription.

Question 108. The beaded appearance of the chromosome is known as:

  1. Centromere
  2. Chromomere
  3. Centriole
  4. Centrosphere.

Answer: 2. Chromomere

Question 109. In mitochondria, cristae act as sites for :

  1. Phosphorylation of flavoproteins
  2. Protein synthesis
  3. Oxidation reduction reactions
  4. Breakdown of macromolecules.

Answer: 3. Oxidation-reduction reactions

Question 110. Raphides found in asparagus are crystals of :

  1. Calcium carbonate
  2. Calcium Citrate
  3. Magnesium oxalate
  4. Calcium oxalate.

Answer: 4. Calcium oxalate.

Question 111. Chromosome puffs in salivary gland chromosomes are the sites of :

  1. Translation
  2. Transcription
  3. Dna synthesis
  4. Dna replication.

Answer: 2. Transcription

Question 112. The fuel-gen nuclear reaction includes the following :

  1. Reaction of deoxyribose with leuco fuschin to give purple colour to dna
  2. The reaction of ribose with leuco fuschin to give pink colour to rna
  3. Removal of purine at the level of the purine deoxyribose glycosidic bond of dna by acid hydrolysis.
  4. All the above.

Answer: 3. Removal of purine at the level of the purine deoxyribose glycosidic bond of dna by acid hydrolysis.

Question 113. The chromosome number in plants can be increased by

  1. Colchicine treatment
  2. Heat treatment
  3. Hormonal treatment
  4. Breeding with their wild varieties.

Answer: 1. Colchicine treatment

Question 114. Balbiani rings are the characteristics of :

  1. Polytene chromosomes
  2. Sex chromosomes
  3. Ring chromosomes
  4. Lampbrush chromosomes.

Answer: 3. Ring chromosomes

Question 115. Chromosomes are made of structural units called

  1. Nucleoli
  2. Nucleosome
  3. Base
  4. Centromere.

Answer: 2. Nucleosome

Question 116. One of the following serves as a temporary storage place for proteins and other compounds synthesized by the endoplasmic reticulum :

  1. Lysosomes
  2. Dictyosomes
  3. Sphaerosome
  4. Microsome.

Answer: 4. Microsome.

Question 117. Polytene chromosomes are formed when :

  1. Chromosome divides but the nucleus does not divide
  2. The nucleus divides but the cell does not divide
  3. Chromatids divide but the chromosome does not divide
  4. The chromosome assumes a lampbrush shape.

Answer: 3. Chromatids divide but the chromosome does not divide

Cell The Unit of Life MCQ for NEET  Question 118. Micrococcal nuclease enzyme :

  1. Cuts the dna from a specific site
  2. Joins the dna segment
  3. Cuts the dna at the junction between nucleosome
  4. Binds the dna with histone.

Answer: 3. Cuts the dna at the junction between nucleosome

Question 119. Cenffomere is required for :

  1. Replication of dna
  2. The poleward movement of chromosome
  3. Cytoplasmic cleavage
  4. Chromosome segregation.

Answer: 2. Poleward movement of chromosome

Question 120. To determine the ultrastructure of cell organelles, the most likely method of successful observation would be:

  1. Phase contrast microscopy
  2. Light microscopy
  3. Electron microscopy
  4. Autoradiography.

Answer: 3. Electron microscopy

Question 121. Mitochondria in a cell are concerned with the formation of:

  1. ATP From ADP
  2. ATP From Pyruvic Acid
  3. Lactic Acid From Citric Acid
  4. ADP From ATP.

Answer: 1. ATP From ADP

Question 122. Which of the following representations correctly explains the function of mitochondrion?

Cell Unit Of Life Structural Organization MCQs Question 122

Answer: 1.

Cell The Unit of Life MCQ for NEET  Question 123. Who was awarded the Nobel Prize for the synthesis of RNA in 1959 :

  1. S. Ochoa
  2. A. Korenberg
  3. Nirenberg
  4. H.G. Khorana.

Answer: 1. S. Ochoa

Question 124. Chlorophyll a is characterized by the side group :

  1. Methyl
  2. Aldehyde
  3. Phytol
  4. Ketone.

Answer: 1. Methyl

Question 125. Endoplasmic reticulum was first discovered by :

  1. Bell
  2. Porter
  3. Golgi
  4. Altrnan.

Answer: 2. Porter

Question 126. The centrosome is rich in :

  1. DNA
  2. RNA
  3. ATP
  4. Enzymes.

Answer: 2. RNA

Question 127. ‘Protein factories’ of the cell to be effective, need :

  1. Fe++
  2. Cu++
  3. Mg++
  4. Ca++

Answer: 3. Mg++

Cell The Unit of Life MCQ for NEET  Question 128. In a eukaryotic cell, the region between the nucleus and plasma membrane is called :

  1. Junction
  2. Nucleoplasm
  3. Cytoplasm
  4. Lumen.

Answer: 3. Cytoplasm

Question 129. Vacuoles are considered as living organelles because they:

  1. Are membrane-bound
  2. Have hormones
  3. Store enzymes
  4. Can arise de novo.

Answer: 1. Are membrane-bound

Question 130. Which of the following is not the correct pairing of structure with function :

  1. Golgi complex: breakdown of complex molecules
  2. Chloroplast: photosynthesis
  3. Mitochondria: production of ATP
  4. Sphaerosome: synthesis and storage of fat.

Answer: 1. Golgi complex: breakdown of complex molecules

Question 131. Proteins that are to be utilized outside the cell are synthesized :

  1. In the mitochondria
  2. On the rear
  3. On the ser
  4. On free ribosomes.

Answer: 2. On the rear

Question 132. Plant cells are connected by channels through their walls called :

  1. Plasmodesmata
  2. Desmosomes
  3. Tight junction
  4. Desmotubules.

Answer: 1. Plasmodesmata

Question 133. Haploid plants can be obtained by culturing :

  1. Root tips
  2. Young leaves
  3. Endosperm
  4. Pollen grains.

Answer: 4. Pollen grains.

Question 134. Pyrenoids are centres for:

  1. Fat production
  2. Starch formation
  3. Protein formation
  4. Enzyme foundation.

Answer: 2. Starch formation

Cell The Unit of Life NEET Questions Question 135. Bacteria are examples of :

  1. Prokaryotic cell
  2. Eukaryotic cell
  3. Organelles
  4. Plastids.

Answer: 1. Prokaryotic cell

Question 136. Which of the following is not found in prokaryotic cells?

  1. Plasma membrane
  2. Cell wall
  3. Nuclear envelope
  4. Ribosomes.

Answer: 3. Nuclear envelope

Question 137. How many membranes comprise the nuclear envelope?

  1. None
  2. One
  3. Two
  4. Three.

Answer: 3. Two

Question 138. Which of the following moves regularly frorn the nucleus to the cytoplasm?

  1. Glycogen
  2. Rna
  3. Dna
  4. Cholesterol.

Answer: 2. Rna

Question 139. The plastids that give fruits and flowers their orange and yellow colour are the :

  1. Leucoplasts
  2. Chloroplasts
  3. Chromoplasts
  4. Protoplasts.

Answer: 3. Chromoplasts

Question 140. The types of cellular organelles that transform energy are :

  1. Chromoplasts and leucoplasts
  2. Mitochondria and chloroplasts
  3. Mitochondria and chromoplasts
  4. Chloroplasts and leucoplasts.

Answer: 3. Mitochondria and chromoplasts

Question 141. Lysosomes contain enzymes capable of:

  1. Aerobic cellular respiration
  2. Digesting part of the cell
  3. Synthesizing proteins
  4. Synthesizing lipids.

Answer: 2. Digesting part of cell

Cell The Unit of Life NEET Questions Question 142. Mitochondria are found :

  1. In all cells
  2. Only in plant cells
  3. Only in animal cells
  4. All eukaryotic cells.

Answer: 4. All eukaryotic cells.

Question 143. Which of the following observations most strongly supports the view that mitochondria contain electron transfer enzymes aggregated into compact association :

  1. Mitochondria have a highly folded inner wall
  2. Disruption of mitochondria yields membrane fragments which can synthesise ATP.
  3. Mitochondria in animal embryos tend to concentrate in cells which become part of locomotory structures.
  4. A contractile protein is capable of utilisation atp has been obtained from mitochondria.

Answer: 2. Disruption of mitochondria yields membrane fragments which can synthesise ATP

Question 144. Hydrogenosomes (identified in 1997) have double membrane help in energy generation in :

  1. Dinoflagellates
  2. Trichomionids
  3. Diatoms
  4. All eukaryotes.

Answer: 2. Trichomionids

Question 145. Human sperm cells move by :

  1. Cilium
  2. Flagellum
  3. Basal body
  4. Hair.

Answer: 2. Flagellum

Question 146. Plant cells are connected by channels through their walls called:

  1. Plasmodesmata
  2. Desmosomes
  3. Tight junctions
  4. Gap junctions.

Answer: 1. Plasmodesmata

Cell The Unit of Life NEET Questions Question 147. Glycolysis is a process found in :

  1. Eukaryotic cell
  2. Anaerobic bacteria
  3. Most muscle cells
  4. Virtually all cells.

Answer: 4. Virtually all cells.

Question 148. The protoplasm is:

  1. True solution
  2. Emulsion
  3. Suspension
  4. Reversible colloidal solution.

Answer: 4. Reversible colloidal solution.

Question 149. The cell organelle common in protista and monera is :

  1. Lysosome
  2. Chloroplasts
  3. Ribosome
  4. Vacuole.

Answer: 3. Ribosome

Question 150. A striking difference between a plant cell and an animal cell is the presence of the former:

  1. Chloroplast
  2. Cell wall
  3. Centrosome
  4. Plasmalemma.

Answer: 2. Cell wall

Question 151. In which component of a mitochondrion atp is synthesized

  1. Crista
  2. Matrix
  3. Fo-fr complex
  4. Plasmalemma.

Answer: 3. Fo-fr complex

Cell The Unit of Life Biology NEET Question 152. Photorespiration occurs in plant cells in :

  1. Dictyosome
  2. Glyoxisome
  3. Peroxisomes
  4. Endoplasmic reticulum.

Answer: 3. Endoplasmic reticulum.

Question 153. Golgi apparatus is lacking in :

  1. Liver cells
  2. Higher plants
  3. Blue-green algae
  4. Yeasts.

Answer: 3. Blue-green algae

Question 154. Polysome is a chain of :

  1. Pinosome
  2. Ribosomes
  3. Phagosomes
  4. Lysosomes.

Answer: 2. Ribosomes

Question 155. Lysosomes containing inactive enzymes are called :

  1. Autophagosomes
  2. Residual bodies
  3. Secondary lysosomes
  4. Primary lysosomes.

Answer: 4. Primary lysosomes.

Cell The Unit of Life Biology NEET Question 156. The chloroplast thylakoids are in the form of;

  1. Interconnected sacs
  2. Independent discs
  3. Interconnected tubules
  4. Stacked discs.

Answer: 1. Interconnected sacs

Question 157. The pattern of microtubule organization in a centriole is:

  1. 9+0
  2. 9+1
  3. 9+2
  4. 9+3.

Answer: 1.9+0

Question 158. In man the amount of water is about :

  1. 35%
  2. 55%
  3. 1O%
  4. 90%.

Answer: 1. 35%

Question 159. The basal body could be another name for centriole given internal structures when :

  1. It gives rise to spindle fibres
  2. Lt divides during mitosis
  3. It gives rise to cilia or flagella
  4. Lt gives basic reactions.

Answer: 3. It gives rise to cilia or flagella

Question 160. How much energy is released for each molecule of oxygen used in :

  1. 114.5 kcal
  2. 124.5 kcal
  3. 134.5 kcal
  4. 144.5 kcal.

Answer: 3. 134.5 kcal

Question 161. What would be a good example of the occurrence of three types of plastids in a developing organ?

  1. Radish
  2. Turnip
  3. Brinial
  4. Tomato.

Answer: 4. Tomato.

Cell The Unit of Life Biology NEET Question 162. Which of the following is the chief energy food in a cell?

  1. Carbohydrates
  2. Nucleotides
  3. Lipids
  4. Proteins.

Answer: 1. Carbohydrates

Question 163. Water enters the cell by :

  1. Endosmosis
  2. Pinocytosis
  3. Phagocytosis
  4. All of the above.

Answer: 4. All of the above.

Question 164. Golgi apparatus resembles :

  1. Ser
  2. Rer
  3. Nuclear envelope
  4. None of the above.

Answer: 1. Ser

Question 165. Materials enter the Golgi complex at :

  1. Cis region
  2. Trans region
  3. Medial region
  4. Trans golgi reticulum.

Answer: 1. Cis region

Question 166. The enzyme peptidyl transferase is present in :

  1. Smaller subunit of the ribosome
  2. Larger subunit of ribosome
  3. Groove between smaller and larger subunits
  4. In the cytoplasm.

Answer: 2. Larger subunit of ribosome

Question 167. Autophagic vacuoles (vesicles) digest :

  1. Pinosome content
  2. Phagosome content
  3. Cell organelles
  4. Microorganisms.

Answer: 3. Cell organelles

Question 168. Lysosomes help in :

  1. Fertilization
  2. Insulin processing
  3. Contraception
  4. All of the above.

Answer: 4. All of the above.

Question 169. F is composed of :

  1. Five polypeptides
  2. 3 Polypeptides
  3. 3 Polypeptides and accessory polypeptides
  4. A, b, c, d and e polypeptides.

Answer: 4. A, b, c, d and e polypeptides.

Question 170. A quant some contains :

  1. 250 Chlorophyll molecules
  2. 350 Chlorophyll molecules
  3. 450 Chlorophyll molecules
  4. 245 Chlorophyll molecules.

Answer: 1. 250 Chlorophyll molecules

Question 171. The flagellum of a eukaryotic cell shows :

  1. 9 + 0 Arrangement
  2. 9 + 2 Arrangement
  3. 1 + 2 Arrangement
  4. 2 + 9 Arrangement.

Answer: 2. 9 + 2 Arrangement

Question 172. Select the self-duplicating organelle :

  1. Mitochondria
  2. Plastids
  3. Centriole
  4. All of these.

Answer: 4. All of these.

Question 173. Peroxisomes and glycosomes are :

  1. Energy transducers
  2. Membrane-less organelles
  3. Microsomes
  4. Microbodies.

Answer: 4. Microbodies.

Question 174. Lysosomes with cell organelles are called :

  1. Primary lysosomes
  2. Secondary lysosomes
  3. Autophagosomes
  4. Residual bodies.

Answer: 3. Autophagosomes

Question 175. Golgi bodies are involved in :

  1. Excretion
  2. Secretion
  3. Atp synthesis
  4. Rna synthesis.

Answer: 2. Secretion

Question 176. The chloroplasts develop limo :

  1. Er
  2. Dictyosome
  3. Nuclear membrane
  4. Proplastids.

Answer: 4. Proplastids.

Question 177. The supporting framework of a cell consists of :

  1. Microfilaments
  2. Microtubules
  3. Both of these
  4. None of the above.

Answer: 3. Both of these

Question 178. A chromosome having equal arms is called :

  1. Metacentric
  2. Submetacentric
  3. Acrocentric
  4. Telocentric.

Answer: 1. Metacentric

Question 179. Chromosomes are stained with :

  1. Eosin
  2. Safranin
  3. Acetocarmine
  4. Borax carmine.

Answer: 3. Acetocarmine

Question 180. Golgi apparatus is most abundantly found in :

  1. Muscle cells
  2. Neurons
  3. Red blood cells
  4. Pancreatic cells.

Answer: 4. Pancreatic cells.

Question 181. Mechanical support to the cell is provided by :

  1. Golgi bodies
  2. Microfibrils
  3. E.r.
  4. Chromatin.

Answer: 3. E.r.

Cell The Unit of Life Biology NEET Question 182. The function of the centrosome is :

  1. Initiation of cell division
  2. Inhibition of cell division
  3. Termination of cell division
  4. None of the above.

Answer: 4. None of the above.

Question 183. A chromosome having a subterminal centromere is :

  1. Telocentric
  2. Acrocentric
  3. Submetacentric
  4. Metacentric.

Answer: 2. Acrocentric

Question 184. Which structure is present in animal cells but is absent in plant cell?

  1. Centrioles
  2. Golgi apparatus
  3. Mitochondria
  4. Endoplasmic reticulum.

Answer: 1. Centrioles

Question 185. The smallest cell organelle is :

  1. Mitochondria
  2. Microfilament
  3. Microtubule
  4. Ribosome.

Answer: 4. Ribosome.

Question 186. Which of the following is the vacuolar membrane?

  1. Cell membrane
  2. Tonoplast
  3. Karyotheca
  4. Er.

Answer: 4. Er.

Question 187. Select the amphipathic organic compound :

  1. Fibroin.
  2. Proteins
  3. Phospholipids
  4. Nucleotides.

Answer: 3. Phospholipids

Question 188. The plastids present in red algae are :

  1. Chloroplast
  2. Rhodoplasts
  3. Phaeoplasis
  4. Leucoplasts.

Answer: 2. Rhodoplasts

Question 189. Dark reactions of photosynthesis occur in :

  1. Stroma
  2. Inter membrane space
  3. Thylakoids
  4. Axe of above.

Answer: 1. Stroma

Question 190. Microtubules were first seen in :

  1. Medullated nerve fibre
  2. Muscle fibre
  3. Non-medullated nerve fitrre
  4. Cellulose fibre.

Answer: 1. Medullated nerve fibre

Cell The Unit of Life Biology NEET Question 191. Maps are found in :

  1. Microtubules
  2. Intermediate filament
  3. Microfilg+ents
  4. Microtrabeculae.

Answer: 1. Microtubules

Question 192. Turgor pressure in plant cells is generally, between:

  1. 5 And 20 atm
  2. 20 And 40 atm
  3. 10 And 30 atm
  4. 1 And 5 atm.

Answer: 1. 5 And 20 atm

Question 193. Hydrogenosomes are found in certain :

  1. Amoebae
  2. Flagellates
  3. Ciliates
  4. Sporozoans.

Answer: 2. Flagellates

Question 194. The nucleus has ribosomes attached to :

  1. Inner membrane
  2. Outer membrane
  3. Chromatin fibres
  4. All of the above.

Answer: 2. Outer membrane

Question 195. Which of the following is a major component of the nucleus?

  1. Dna
  2. Lipids
  3. Rna
  4. Proteins.

Answer: 4. Proteins.

Question 196. The nucleolus is especially rich in :

  1. Dna and proteins
  2. Rna and proteins
  3. Dna and proteins
  4. Rna and lipids.

Answer: 3. Dna and proteins

Question 197. Chromosomes are best seen in :

  1. Interphase
  2. Metaphase
  3. Anaphase
  4. Telophase.

Answer: 3. Anaphase

Question 198. In spermatogenesis, the acrosome of the sperm is formed by:

  1. Mitochondria
  2. Nucleus
  3. Lysosome
  4. Golgi complex.

Answer: 3. Lysosome

Question 199. Polytene chromosomes were first seen in :

  1. Drosophila
  2. Fruit fly
  3. Chironomus larva
  4. None of the above.

Answer: 3. Chironomus larva

Question 200. Synaptonemal complex is associated with :

  1. Polytene chromosome
  2. Lampbrush chromosome
  3. Mitotic chromosome
  4. Paired meiotic chromosomes.

Answer: 4. Paired meiotic chromosomes.

Question 201. The beaded areas on chromosomes are known as :

  1. Centromere
  2. Cristae
  3. Chromomeres
  4. Cistron.

Answer: 3. Chromomeres

Question 202. Stem cells is an alternative term for :

  1. Dedifferenriared cells
  2. Redifferentiated cells
  3. Undifferentiated cells
  4. Differentiated cells.

Answer: 3. Undifferentiated cells

Question 203. Cell biology is the study of :

  1. Cell structure
  2. Cell Function
  3. Cell division
  4. Cell structure and function.

Answer: 4. Cell structure and function.

Question 204. Which of the following is time?

  1. A cotton fibre is made up of 1500 fibrils
  2. A fibril has 250 microfibrils
  3. A microfibril has 20 micelles
  4. All of above.

Answer: 4. All of the above.

Question 205. Channel has been discovered by :

  1. Singer and Nicholson
  2. Garnier
  3. Robinson and brown
  4. Nehar and salesman

Answer: 1. Singer and Nicholson

Question 206. Pelviz et al discovered :

  1. Microtubules
  2. Microfilaments
  3. Centriole
  4. Peroxisome.

Answer: 1. Microtubules

NEET Biology MCQ Cell The Unit of Life Question 207. Nucleoplasmin occurs inside :

  1. Chromatin
  2. Nucleolus
  3. Nucleoplasm
  4. Nucleopores.

Answer: 4. Nucleopores.

Question 208. Match the items of column 1 with the items of column 2

Cell Unit Of Life Structural Organization MCQs Match The Column 208

  1. (1-D), (2-E), (3-F), (4-A) (5-B), (6-C)
  2. (1-D), (2-E), (3-A), (4-F), (5-B), (6-C)
  3. (1-D), (2-E) (3-F), (4-C) (5-A), (6-B)
  4. (1-D), (2-F), (3-C), (4-E), (5-A), (6-B).

Answer: 3. (1-D), (2-E) (3-F), (4-C) (5-A), (6-B)

Question 209. Match the items of column 1 with column 2

Cell Unit Of Life Structural Organization MCQs Match The Column 209

  1. (1- c), (2- d), (3- e), (4- b), (5- a)
  2. (1- c), (2- d), (3- b), (4- c), (5- a)
  3. (1- c), (2-d), (3- a), (4-b), (5- e)
  4. (1 – c), (2- d), (3- e), (4- a). (5- b).

Answer: 1. (1- c), (2- d), (3- e), (4- b), (5- a)

Question 210. Match the items of column 1 with the items of column 2

Cell Unit Of Life Structural Organization MCQs Match The Column 210

  1. (1 – C), (2 – d), (3 – a), (4 – b), (5 – e)
  2. (1- C), (2 – a), (3 – d), (.4 – e), (s – b)
  3. (1- C), (2 – d), (3 – e), (4 – a), (5 – b)
  4. (1- C), (2 – d), (3 – b), (4 – a), (5 – e).

Answer: 3. (1- C), (2 – d), (3 – e), (4 – a), (5 – b)

Question 211. Match the terms in column a with suitable terms

Cell Unit Of Life Structural Organization MCQs Match The Column 211

  1. (1-c), (2-f), (3-a), (4-e) (5-b),(6-d)
  2. (1-c), (2-f), (3-a), (4-b), (5-d),(6-e)
  3. (1-c), (2-f) (3-a), (4-e) (5-d),(6-b)
  4. (1-c), (2-d), (3-a), (4-e), (5-b),(6-f)

Answer: 1. (1-c), (2-d), (3-a), (4-b) (5-e)

Question 212. Enzymes associated with converting fats to carbohydrates are located in which organelle?

  1. Liposomes
  2. Golgi bodies
  3. Glyoxysomes
  4. Microsomes.

Answer: 3. Glyoxysomes

Question 213. Which of the following is covered by a single membrane?

  1. Nucleus
  2. Mitochondria
  3. Chloroplast
  4. Sphaerosomes.

Answer: 4. Sphaerosomes.

Question 214. Dna is ‘mainly’ found in :

  1. Nucleus only
  2. Cytoplasm
  3. Nucleus and cytoplasm
  4. All the above.

Answer: 1. Nucleus only

Question 215. What is common between chloroplasts, chromoplasts and leucoplasts?

  1. Presence of pigements
  2. Possession of thylakoids and Gama
  3. Storage of starch, proteins and lipids
  4. Ability to multiply by a fission-like process.

Answer: 4. Ability to multiply by a fission-like process.

Question 216. Organelle connected with glycoside

  1. Ribosome
  2. E.r.
  3. Mitochondrion
  4. Chloroplast.

Answer: 2. E.r.

Question 217. The Centre of phosphorylation is :

  1. Ribosome
  2. Oxisome
  3. Peroxisome
  4. Sphaerosome.

Answer: 3. Peroxisome

 

Structural Organisation in Animals For NEET Biology

by

Structural Organisation In Animals For NEET Biology Morphology Of Animals Pheretima Posthuma (Earthworm)

Earthworm belongs to the phylum annelida class oligochaeta.

Habitat:

Pheretima posthuma, the prevalent Indian earthworm, is a significant representative of the phylum Annelida. It is a fossorial creature.

  • It inhabits burrows constructed in soft, damp soil abundant in decomposed organic material or humus.
  • It excavates its burrows mostly in the pliable soils of gardens, lawns, or pastures. The burrows can stretch vertically downward to a depth of 30-60 cm.
  • During spring and summer, the burrows may extend to a depth of 180-240 cm when moisture is present.

In the rainy season, the burrows become inundated, prompting the worms to exit and traverse the damp soil surface.

Read and Learn More NEET Biology Notes

Habits.

  1. Earthworms are nocturnal. During the daytime, it remains passively in the burrow with its anterior end directed upwards and posterior end downwards. At night, it becomes active.
    • It may come out of the burrow and roam about. Sometimes it keeps the posterior end fixed to the burrow and moves the anterior part of the body in a circle. It feeds on soil particles rich in decaying organic matter or humus.
    • It can also ingest directly the bits of leaves and other organic matter. The undigested food is egested as worm casting which appears as heaps on the soil.
  2. Earthworm respires through the skin which is very thin and highly vascular. It is always kept moist. The exchange of gases takes place by diffusion through the skin.
  3. Locomotion is affected by the contraction and relaxation of muscles of the body wall aided by setae or chaetae. The setae are embedded in setal sacs. They can be protruded or retracted. During locomotion, the anterior part of the body is extended.
    • It is fixed to the substratum by setae. The posterior part of the body is drawn forward towards the anterior part. It is then fixed to the substratum by the setae and again the anterior part is stretched.
    • This process is repeated. Thus, earthworms creep slowly on the surface of the soil. The setae hold the substratum firmly when the worm is making burrows, the earthworm can move backwards by reversing the direction of the setae.
    • The backward movements occur when it has to come out of the burrow. The earthworm moves at the rate of 25 centimetres per minute.
  4. There are no special sense organs like eyes, ears etc. However the skin of earthworms lodges receptor cells and is highly sensitive to light and soil vibrations. The worm has a sense of smell and can detect food immediately.
  5. The earthworm is hermaphrodite bisexual or monoecious. It is oviparous. There is no self-fertilisation because it is protandrous. Thus, there is cross-fertilisation.
    • During copulation, two earthworms are closely attached by their ventral surfaces in such a way that the head region of one is opposite the tail region of the other.
    • There is a mutual exchange of spermatic fluid. Then the two worms separate.

Structural Organisation In Animals For NEET Biology Features Of Pheretima Posthima (Earthworm)

1. Earthworms are metamerically segmented nocturnal animals, that live in burrows made in the soft, moist soil of gardens, lawns, forests, pastures, flower beds and the soil rich in decaying organic matter or humus.

  • They are rarely found in dry, sandy and clayey soils. They usually lie in the upper layers of soils.

2. The earthworm moves by muscular contraction and expansion of the body aided by chitinous setae present in the body wall.

3. Its body is elongated, 100-120 segmented, cylindrical and pointed at both ends. It measures about 150 mm in length and about 3 to 5 mm in diameter.

  • The dorsal side of the earthworm is darker brown due to the deposition of a brown-coloured substance known as porphyrin which is derived from the decayed leaves, on which the earthworm feed.
  • The first segment is called the peristome with an extension of the fleshy lobe, and proscenium, and segments 14-16 are covered by clitellum.

4. Apertures. Many apertures are found on the external surface which are openings of the coelom, alimentary canal, and the excretory and genital organs.

  • Mouth. It is a crescentric anterior aperture present in the first segment called peristomium.
  • Anus. It is a vertical slit-like aperture present at the posterior end of the last segment called the anal segment or pygidium.
  • Female genital pore. It is a single median aperture of the oviducts present on the ventral side of the 14th segment. Eggs pass out of this aperture.
  • Male genital pores. They are a pair of crescentric openings of the common prostate spermatic ducts present in the 18th segment on the ventral side.
  • Genital papillae. There are two pairs of genital papillae present in the 17th and 19th segments on the ventral side. They bear the minute openings of accessory glands.
  • Spermathecal pores. They are four pairs of apertures, each pair is present in the grooves of 5/6, 6/7, 7/8 and 8/9 segments. They are ventrolateral in position.
  • Nephridiopores. These are minute openings of the integumentary nephridia present in the body walls. They are scattered in all the segments except the first two segments.
  • Dorsal pores. These are minute pores of coelomic chambers located mid-dorsally, one in each inter-segmental groove, behind the 12th segment.

5. Body wall. It is covered with a very thick cuticle. The body wall consists of the following layers,

  1. Cuticle
  2. Epidermis
  3. Circular Muscles
  4. Longitudinal Muscles
  5. Coelomic Epithelium.
  6. The epidermis is one cell in thickness and consists of
    • Mucus secreting cells.
    • Albumen secreting cells.
    • Sensory cells,
    • Supporting cells.
    • Basal Cells.

6. The Coelom. There is a true coelom present in earthworms. It is partitioned into so many coelomic compartments with the help of septa. The first septum lies between 4/5 segments and is thin and membranous.

  • In the coelom is present milky white fluid known as coelomic fluid which is slightly acidic.
  • There are several types of corpuscles present in the coelomic fluid.
    1. Phagocytes. Amoeboid in shape and destroys foreign bacteria.
    2. Chloragogen cells. These are yellow-coloured and have excretory functions.
    3. Mucocytes. These are fan-shaped corpuscles.
    4. Circular nucleated cells,
    5. Eliocytes.

7. Digestive System. The alimentary canal consists of the following parts situated in the segments as mentioned.

  • The mouth is situated on the ventral side of the first segment. It opens into the buccal cavity which lies in the first 3 segments. This opens into the pharynx situated in the fourth segment.
  • From the 5th to the 7th segment is the oesophagus followed by a highly muscular structure known as gizzard situated in the 8th segment. From the 9th to 14th segments lies the stomach.
  • From the 15th segment to the last segment is the intestine. The intestine is divided into 3 parts known as:
    • Pretyphlosolar region. (15th to 26th segments)
    • Typhlosolar region. (27th to near end except for last 20-25 segments)
    • Post-typhlosolar region. (situated in the last 20-25 segments).

8. Excretory System. Excretion takes place through a large number of coiled tubular structures known as nephridia. These are the excretory units. There are 3 types of nephridia found in earthworms:

Morphology Of Animals Ventral View Of Earthworm

  1. Ventral view of earthworm
  2. Anterior region
  3. A seta
  4. Genital area (Ventral view)

Morphology Of Animals Pheretima Posthuma- Circulatory System In Lateral View.

Morphology Of Animals Alimentary Canal Of Earthworm

Morphology Of Animals Testis and septum

 

  • Integumentary Nephridia: These are mesonephric, present on their)her side of the body wall in all the segments except the first two segments. Their number is 200 to 250 in each segment except in clitellum, where they are 10 times more. These arcs are known as “Forests of nephridia.”
  • Septal Nephridia: These are enteronephric and situated behind the 15th segment attached to the septa, on both sides. Each row has 80 to 100 septal nephridia. They are enteronephric.
  • Pharyngeal Nephridia: They are enteronephric. Three groups of pharyngeal nephridia are situated in each of the 4th, 5th and 6th segments, Out of all the 3 types of nephridia, only septal nephridia have a funnel-shaped structure known as nephrostome and thus can collect the waste products from the coelomic fluid, other two types don’t have nephrostome.

9. Vascular System. It consists of a closed tube of the blood vascular system. The haemoglobin is found dissolved in the plasma. It consists of hearts, blood vessels, anterior loops and blood glands.

10. Male Reproductive System. Earthworm is a bisexual (hermaphrodite) animal. The male reproductive organs consist of two pairs of testes situated in the 10th and 11th segments.

  • Each testis is enclosed in a fluid-filled testis sac. There are 2 pairs of seminal vesicles situated in the 11th and 12th segments. The testes sacs communicate with corresponding seminal vesicles.
  • Just beneath each testis lies a funnel known as a spermicidal funnel. From each funnel is given out a duct known as vas deferens. The two pairs of vasa deferentia open into the prostate glands lying from 17th to 20th segments.
  • From each prostate gland is given out a duct known as a common prostate spermatic duct. These ducts open on the ventral side of the 18th segment through male genital apertures.

11. Female reproductive organs consist of one pair of ovaries situated in the 13th segment. Just close to each ovary is a funnel, known as the oviducal funnel. Both the oviducal funnels open into oviducts.

  • Both the oviducts enter into the 14th segment and open outside through the female genital aperture. Female reproductive organs also include 4 pairs of spermathecae situated in the 6th, 7th, 8th, and 9th segments.
  • The spermathecae open to the exterior through 4 pairs of spermathecal pores situated in the inter-segmental grooves of 5/6, 6/7, 7/ 8 and 8/9 segments.

Morphology Of Animals Ovary And Septum

Morphology Of Animals Pheretima Posthuma Reproductive System

Structural Organisation In Animals For NEET Biology Periplaneta Americana (Cockroach)

Cockroach belongs to the phylum Arthropoda and class Insecta.

Habitat and Habits:

The cockroach is nocturnal, being active at night. Throughout the day, they conceal themselves beneath stones, moist foliage, timber, and various forms of trash.

  • Domestic cockroaches inhabit residences, particularly kitchens, storage areas, latrines, sewage systems, ships, and railway cars.
  • Certain species inhabit ant nests, while a few are semiaquatic.
  • It is highly voracious and omnivorous, consuming any form of animal or vegetable matter that it encounters. It prefers warmth, as it is intolerant of cold. It is a cursorial animal.

The sexes are distinct. It exhibits sexual dimorphism. Life history exhibits steady transformation.

Features of cockroach:

  • Shape and size: The body of a cockroach is flat and broad. It is bilaterally symmetrical. The length of the adult is about 1” to 2”, while the breadth is about 1/2″.
  • Colour: The colour is reddish brown while there are two dark patches surrounded by a light-brown margin in the first thoracic segment.
  • Exoskeleton of Cockroach: The entire body of the cockroach is covered with a thick, hard, dark-coloured chitinous cuticle. It forms the exoskeleton which is secreted by the epidermis.

Thus the body wall is sclerotized or hardened to form sclerites.

These sclerites are joined together by the soft flexible membrane called suture by which movement of the body segment and appendages is possible. Thus, the body is segmented.

  • The body of a cockroach is divided into three parts: Head, thorax and abdomen.
  • The head of the cockroach is a hypognathous, strong head capsule or cranium.
  • The Head has three types of sense organs: eyes, antennae and fenestrae.
  • The head has biting and chewing-type mouth parts which are formed of a labrum, one pair each of mandibles and first maxillae, labium and hypopharynx.
  • Mouth-parts: Those parts, which surround the mouth, are called mouth-parts. The cockroaches are as follows :
    1. Upper lip or labrum.
    2. Mandible
    3. First maxillae
    4. Second maxillae
    5. Hypophar ynx or lingua.
  • The Thorax of cockroach bears three pairs of legs and two pairs of wings or pereopods.

Each leg is formed of five podomeres.

1. Wings of Cockroach: There is a pair of wings in the mesothorax and metathorax. These are movably joined to the anterior comers of the terga.

  • Each wing consists of membranous expansions of the cuticle thickened by a network of chitinous ridges or nerves or veins which support the wings.
  • The anterior mesothoracic wings are called forewings which are dark, opaque, home. Forewings are not used in flight but in a state of rest, they protect the living-wings by overlapping them.
  • Hence, these wings are known as fore wings or wing-covers elytra or tegmina. The hindwings or metathoracic wings are thin, membranous, transparent broad, delicate and are used in flight.
  • When at rest they are kept folded and laid back over the abdomen under the elytra or wing covers.

2. Leg of Cockroach: There are three pairs of legs, each leg consists of

  • Basal podomere or coxa which articulates with the sternum,
  • Small trochanter or articular joint which is fused to
  • Enlongated and fairly shout femur,
  • A slender and spiny tibia and
  • The tarsus or foot is composed of five short movable podomeres. The last podomere ends in the two claws, also known as pretarsus. Between the two claws, there is a delicate porous pad called the arolium or pulvilus, which is densely covered with bristles and helps in clinging.

3. The abdomen of cockroaches in both sexes bears one pair of anal cerci and apophyses. A male cockroach has anal styles while a female cockroach has brood pouches.

Structural Organisation In Animals Neet Notes Differences between male and female cockroaches

Morphology Of Animals Differences Between Male And Female Cockroach

Morphology Of Animals Dorsal View Of Cockroach

Morphology Of Animals Head Of Cockroach Front View

Morphology Of Animals Alimentary Canal And Associated Glands Of Cockroach

Morphology Of Animals Mouth Parts Of A Cockroach

Morphology Of Animals Antenna Of Cockroach

Morphology Of Animals Leg Of Periplaneta And Last Portion Of The Leg Showing Arolium

Morphology Of Animals Reproductive System Of Male Cockroach In Dorsal View

Morphology Of Animals Female Reproductive Organ In Dorsal View

4. The alimentary canal is made up of stomodeum (Foregut). Mesenteron (Midgut) and proctodaeum (Hindgut). The stomodeum and proctodaeum are lined internally by ectoderm whereas the mesenteron is lined by endoderm.

  • The foregut consists of the mouth, pharynx oesophagus, crop and gizzard. In the gizzard are present 6 hard cuticular teeth which help in the mastication of the food. There is a stomodaeal valve present in the posterior region of the gizzard.
  • The middle part of the alimentary canal is known as the mesenteron. At its anterior end are present 7-8 blindly ending tubular structures known as mesenteric caecae and at the posterior end are present the malpighian tubules.
  • The hindgut is made up of the ileum, colon and rectum. One pair of salivary glands are present at the antero-ventral side of the crop.
  • Each gland has a reservoir and bipartite glandular portion. A common efferent salivary duct from both glands opens at the base of the hypopharynx.

5. The Circulatory System is of open type. The blood is colourless, without haemoglobin, known as haemolymph. The body cavity (Haemocoel) is divided into 3 cavities by two diaphragms known as pericardial sinus, perivisceral and perineural sinuses.

  • The heart is situated in the pericardial sinus and is made up of 13 segmentally arranged funnel-shaped chambers.
  • There are fan-shaped muscles attached to the hearts in each segment known as alary muscles which help in opening and closing the ostia. The haemolymph flows in the heart in the forward direction.

6. Excretion is carried out by about 60 fine, yellow, unbranched, thread-like blind tubes called malpighian tubules. The main excretory product is uric acid.

  • Respiration is carried out through the trachea.
  • Compound eyes are formed of many optical units called ommatidia and the image formed is mosaic.

7. Male reproductive organs. It consists of one pair of testes, situated from 3rd to 6th abdominal segments. Each testis gives out a vas deferens. Both the vasa deferentia run posteriorly and open into an ejaculatory duct, where lies a gland known as the utricular gland.

  • This gland has 3 types of tubules known as long peripheral tubules, short central tubules and one pair of seminal vesicles which store the sperms. The ejaculatory duct runs posteriorly and opens outside through an aperture known as the male gonopore.
  • Around the male gonopore are situated a few chitinous structures known as male gonapophysis. This is made up of 3 phallomeres—left, right and ventral phallomeres.
  • The left phallomere has some structures known as Titilator, Pseudopenis and Asperate lobe. All these help during copulation. The sperms of cockroaches are released in the form of a bundle known as spermatophore which is surrounded by 3 layers.

8. Female Reproductive organs. It consists of one pair of ovaries lying from the 3rd to 6th abdominal segments. Each ovary is made up of 8 beaded structures known as ovarioles, in which the eggs are arranged linearly in order of development.

  • From each ovary arises a duct known as the oviduct. Both the oviducts join to make a common duct known as the vagina, which opens into the genital chamber through the female gonopore.
  • In the gonopore lie a pair of spermathecae, one pair of collateral glands and six chitinous plates known as ovipositors.

9. Ootheca formation and egg laying. The eggs are laid in a brown, home purse-like egg case called an ootheca. The egg cases are laid in a dark place in a crevice, in the dirt, pushed down by the ovipositor.

  • Each egg case contains 16 fertilized ova (eggs) in two vertical rows. Each egg in the egg case hatches into a colourless young cockroach called a nymph.
  • Nymph, hatched undergoes gradual metamorphosis (6-9 moults) to form an adult.

Structural Organisation In Animals For NEET Biology Rana Tifirina (Frog)

Habitat of frog: Habitat means the natural abode (home) of an animal. Rana tigrina is commonly found in or near water of ponds, lakes, ditches, wells etc. It is an amphibious animal.

Habits

  1. Feeding: The frog is mainly insectivorous. It feeds on living and moving insects, spiders and worms. It also shows cannibalism as the larger frogs eat up the smaller ones. It captures its prey with the help of its tongue.
  2. Locomotion: It is through swimming-leaping and floating.
  3. Croaking. During the rainy season, a noisy chorus of croaking frogs is often heard in the evening or at night. When the air from the lungs is exhaled, it sets the vocal cord, and presents the laryngotracheal chamber, with vibrations and thus voice or croaking is produced.
    • The male frogs croak more loudly than the females. They possess a pair of large, distensible vocal sacs, one on either side of the throat. The vocal sacs act as resonators and help in raising the mating call for the female.
  4. Breeding: During the rainy season (i.e. from July to September) frogs collect in some quiet, shallow water pond and croak loudly. The male and female frogs undergo pairing.
    • The swellings called copulatory or nuptial pads help in clasping the female firmly. The couple remains in this condition for several days and can swim in water; the female mainly bears the burden of the male during swimming.
    • The female ultimately lays an egg over which the male sheds its spermatic fluid. The sexual embrace between a male and a female frog which leads to the laying of the egg by the female and the discharge of sperm by the male is called amplexus or pseudocopulation.
    • It differs from the process of copulation in which the male transfers its sperm inside the body of the female. After amplexus, the male frog gets down the female and both start living separately.
  5. Hibernation. A frog is a cold-blooded or poikilothermal animal. Its body temperature does not remain constant, but it changes according to the temperature of the surroundings in which it lives.
    • In winter, the temperature of its body falls considerably. It cannot bear the severe cold of winter. Its metabolic activities are slowed down and this may ultimately lead to death.
    • To avoid this, it buries inside the mud or moist soil. It may burrow about 60-90 ems deep. There it lies in a state of rest or sleep. It does not move. Its mouth and nostrils are kept closed.
    • It respires through the skin. It does not feed and lives on food stored as glycogen in the liver and fat in the fat bodies. In this condition, it rests or sleeps throughout winter.
    • This particular condition of rest in winter by frogs is called winter sleep or Hibernation. At the approach of spring, warmth wakes it up and it comes out of its burrow and again begins to lead an active life.
  6. Aestivation. During summer, when the temperature is quite high, the frog again goes deep into the water. It may bury itself in the mud at the bottom of the pond. The pond may dry up. The frog remains inactive and can tide over the unfavourable period.

Structural Organisation In Animals Class 11 Ncert Solutions Features of frogs

Structural Organisation In Animals Neet Important Questions Size, Shape and Colour

  • Frog has an ovoid and dorsoventrally flattened body which is streamlined. It has a length of 10-17 cm and a breadth of 5-8cm.
  • The body shows external bilateral symmetry whereby the right and left halves of the body are mirror images of each other. The animal has anterior, posterior, ventral, dorsal and lateral sides.

Body Covering

  • The body is covered over by a loosely attached skin. The surface of the skin is smooth and soft. It is also slippery because it secretes a thin film of mucus.
  • Due to the looseness of the skin, several longitudinal wrinkles appear especially on the dorsolateral sides. They are called dermal plicae.

Body Divisions

  • The body of the animal can be divided into two parts, head and trunk. The tail and neck are absent.
  • To the anterior and posterior parts of the trunk are attached limbs, one on either side.

Head

  • The head of the frog is roughly triangular in outline. It is flattened. The anterior upper part of the head is called the snout.
  • The snout is blunt. The mouth is in the form of a transverse slit which runs throughout the border of the head.
  • It is normally kept closed except at the time of the feeding. Just behind the tip of the snout are found two small dorsal openings called external nares or nostrils. The top of the head bears two dorsolateral large and bulging eyes.

The position of the eyes enables frogs to see in different directions even in the absence of a neck. Each eye has three eyelids. – upper, lower and nictitating membrane.

  • The upper eyelid is opaque, pigmented and thick. It is almost immovable. The lower eyelid is small and semitransparent. It is slightly movable. The nictitating membrane is also called the third eyelid.
  • It arises from the inner surface of the lower eyelid. The nictitating membrane is transparent and freely movable to cover the whole eyeball. It protects the eyeball from mud and water.
  • Outside water, keeps the eyeball moist. The eye can be withdrawn into the head. Just anterior to the eyes, is found a small dorsal and light-coloured swelling called a brow spot.

Behind each eye is found an obliquely placed circular membranous patch named tympanum ear drum or tympanic membrane. It is bounded using a slightly raised ring of cartilage. External pinna or ear is absent.

  • The ventral surface of the head is soft and is called the throat. It is alternately raised and lowered in a type of breathing.
  • In males, the throat beats two bluish and wrinkled particles towards the posterior end. They are called vocal sacs. The vocal sacs can be Inflated to act as resonators of sound.

Trunk

  • The main body or trunk is flattened and oval. It can be distinguishable Into the anterior hard chest and posterior sort belly or abdomen.
  • The posterior end beats a small circular apci line called the cloacal aperture. It is a common opening for the passage of animal excreta, urine, eggs or sperm.

Pairs of Pcntadactyl Limbs

The trunk bears two pairs of appendages, forelimbs and hind limits. Therefore, Hie’s animal is a quadruped. The lore limb has three parts-upper arm or hrucliltim, fore units or antebradiium and hand or maims.

  • The hand is further distinguishable into three parts carpus, palm or metacarpus and fore-diglsts or lingers. There are only four fingers. The finger corresponding to our thumb is absent.
  • However, it can fall under the skin. The first or inner among the remaining four is equivalent to our index linger.
  • This finger develops ampleuxsory or nuptial pad during the breeding season in males, Articular pads occur on the under-surface of the finger joints.

In the silling position die lore limbs arc bent outwardly in the elbow region. The hind limbs or legs are differentiated into a proximal thigh or femur, a middle shank or crus and a distal fool or pes.

  • The foot has diree parts ankle or tarsus, metatarsus or instep and live toes or bind digits. The membranous fold of skin or web occurs between die toes. The first toe is called hallux.
  • The fourth toe is the longest. A prehnlhix or sixth toe can fall under the skin, Articular pads occur on die under-surface of toe joints. In the selling position, the hind limbs are folded like the letter Z.

Morphology Of Animals Alimentary Canal And Associated Gland Of Frog

Morphology Of Animals Frog (Sitting Position)

Morphology Of Animals Male Urinogenital System Of Frog

Morphology Of Animals Female Urinogenital System Of Frog

Rattus Rattus (Rat)

  • Common Indian black rat (Rattus rattus) in nocturnal, inhabiting holes and burrows.
  • A rat is about 20 cm in length, its body is covered by hair, except in a few places and is characterized by a fusiform body.
  • The rat is bilaterally symmetrical. Its body is covered over by soft fur of hairs shown as pelagae. It is black dorsally and grey on its ventral side.

Features of Rat

  • Its body is 15 to 20 cm in length and is divided into 4 regions.
    1. Head
    2. Neck
    3. Trunk
    4. Tail
  • The integument is made up of epidermis, dermis and their derivatives.

Rat External characters.

1. Head. It lies at an angle with the long axis of the rest of the body. It is elongated and conical. It is broad posteriorly and tapers anteriorly into a naked snout.

  • At the tip of the snout, is a short, transverse opening, known as the mouth, The mouth is bounded by fleshy and movable upper and lower lip. The upper lip bears a cleft in the middle to form the hair lip.
  • Through this cleft of the upper lip, the incisors are visible. Just above the mouth, are situated two inverted comma-like nostrils or external nares, which lead into the nasal chambers.
  • Behind the nostrils, on the side of the head, lies a prominent bulging eye. The eyes are black and the pupils are rounded. Each eye is bounded above, and below by movable and opaque upper and lower eyelids.

The eyelids are provided with very fine and short eyelashes. The third eyelid i.e., the nictitating membrane is also present at the inner corner of each eye.

  • The meibomian glands, which are situated at the margin of the eyelids, are very prominent or conspicuous. Behind the eyes, the head bears posterolaterally, a pair of external cars or pinnae. The pinnae are meant for collecting sound waves.
  • On the sides of the snout and also above the below eyes, are present long, stiff, bristle-like hairs, called whiskers or vibrissae.
  • They are sensitive to touch and they enable the animal to judge whether it can pass through a Morphology Of Animals Rattus Rattus (House Rat)

2. Neck. It is short and without anything special. It simply connects the head with the trunk and enables the former to move in all directions.

3. Trunk. It is lightly compressed dorsoventrally and divisible into two regions.

  1. Thoracic region.
    • It is the anterior small region of the trunk and is also known as the chest.
    • It is strengthened by the ribs.
    • It encloses the heart and the lungs.
  2. Abdominal region.
    • It is the posterior larger and soft region of the trunk.
    • It is without ribs and encloses the remaining viscera of the body.
  3. On the ventral side of the trank of females, are present six pairs of teats or nipples or mammae on which open the milk glands.

Three pairs of teats are present in the thoracic region and the remaining three pairs are restricted to the abdominal region of the trank. In males, the teats are vestigial.

There are two pairs of limbs, attached at the anterior and posterior sides of the trank. The limbs are constructed on the pentadactyl pattern.

Morphology Of Animals External Features Of Female And Male (Posterior Region)

Each forelimb consists of an upper arm or brachium, forearm or antebrachial and hand or manus. The hand has a wrist or carpus, palm or metacarpus and 4 well-developed lingers or digits.

  • The thumb is vestigial. Each digit ends in a horny claw, which is well developed and is used for digging the burrows.
  • Each hind limb is divided into a thigh or femur, a shank or crus and a foot or pes. The foot consists of an ankle or tarsus, insteps or sole or metatarsus and 5 clawed digits to toes.
  • The typical walking pads are present on the tips of the digits, palms and the insteps. The palms and soles are not hairy.

At the posterior extremity of the trunk, underneath the base of the tail, lies an opening, the anus. It is the posterior opening of the alimentary canal.

  • In front of the anus, oh the ventral side of the trunk, are present the external sex organs. In male rats, they consist of a pair of scrotal sacs, containing testes and a retractile penis, the copulatory organ.
  • The distal part of the penis is very sensitive and known as the glans penis, covered over by a loose fold of integument, the prepuce. At the tip of the penis is situated the urinogenital opening.
  • In female rats, the sex organs are marked by an opening of the vulva which leads into the vegina.

In front of the vulva, is present the urethral orifice, situated on a short papilla. Unlike male rats, the urinary and genital openings are separate in female rats.

4. Tail. It is long and covered with small overlapping scales. Emerging from under the leg of each scale, are three short bristle-like hairs. The tail is a balancing organ.

Structural Organisation In Animals Neet Previous Year Questions  Interaction of Earthworms with mankind

The Earthworms are both beneficial and harmful to man directly or indirectly.

Beneficial aspects: The beneficial aspects of the Earthworm are as follows:

1. Beneficial to agriculture: The Earthworms are of enormous value to agriculturists in the following ways:

  • The burrows of the Earthworms make the soil more combed which becomes porous and serves better for respiration and penetration of the developing roots. The earthworms are considered to be natural ploughs.
  • The decaying vegetation which is carried by Earthworms into the burrows enriches the soil.
  • The soil particles are broken into a fine state when they pass through the muscular gizzard.
  • The Earthworms bring out fresh soil in the form of castings and thus a thick layer of humus is formed. Along with the castings, nitrogenous matters are also given out which are added to the soil and used by the plants.
    • According to Charles Darwin, there are about 53,000 Earthworms in one acre of soil.
    • He estimated that in a single year, about 80 tons of castings are added to the surface of soil in one acre and can cover the surface by a layer of about 1/5 inch. Thus the earthworms are known as friends of the farmers.

2. As food for man: In many countries such as China, Japan, Burma etc. Earthworms are used as food for man. The edible preparations are made in many ways.

3. As medicines: Earthworms are also used as medicines. It is said that it cures stones in the bladder, jaundice, piles, diarrhoea, sexual impotency etc.

4. As bait for fishing: Earthworms are also used as bait for fishing. These are cut into small pieces and used as baits. In many countries, there are separate centres for the sale of earthworms.

5. Use in the laboratory: As earthworms are commonly found all over the world they are used for dissections in zoological laboratories.

6. As a dispersal agent: The dispersal of small seeds and fruits is also done by Earthworms.

Harmful aspects: The Earthworms are also harmful in the following ways:

  1. They spoil the fields and the gardens. Burrows often cause water-oozing and soil erosion.
  2. Earthworms also act as intermediate hosts of some parasites such as Monocystis, the cestoda, and Amoeba. Taenia and the Metastrongilus.
  3. The Earthworms also damage the plants. Pheretima damages the roots of Piper Betel in Coimbatore. It also damages the roots of paddy in Malabar. However, the Earthworms are more beneficial to man.

Structural Organisation In Animals Neet Mcqs With Answers Interaction of Cockroach with Mankind (Economic Importance)

  1. Harmful activities
    • It damages household materials like clothes, shoes, purses, etc.
    • It contaminates the foodstuffs and befouls them so that they become unpalatable.
    • These also act as vectors for the germs of some diseases like cholera, diarrhoea, typhoid, etc.
  2. Useful activities
    • These are used as food by the people of some South American countries and Myanmar.
    • These are used as food for many useful animal types like amphibians, lizards, birds and rodents.
    • Cockroaches are used as safe experimental animals for laboratory experiments and biological research as these are easily available.

Structural Organisation In Animals Neet Revision Notes  Interaction of frog with mankind (Economic Importance)

A frog is a useful animal for to following reasons:

  1. A frog is used in biological control as eats upon crop’s pest insects which also saves the expenditure on the insecticides.
  2. A frog is used as an experimental animal for teaching, research, pharmacology, etc.
  3. Its muscular legs are used as food in some parts of India and many other countries.
  4. Small froglets are used as fish bait.

Structural Organisation In Animals Neet Study Material Interaction of Rats with Mankind

Beneficial activities:

  • It serves as a crucial element of the food chain, providing sustenance for many reptiles, birds, and mammals.
  • It is utilized as sustenance for individuals in certain nations.
  • It is beneficial in education and biomedical research.
  • These are utilized as experimental subjects to investigate the effects of pharmaceuticals for eventual application in human medicine.
  • These are utilized in genetic studies to examine traits such as variances in coat color.

Detrimental actions:

  • These serve as significant pests of crops and stored grains, inflicting harm on approximately 20 percent annually.
  • These entities undermine the roots of plants by creating burrows and tunnels.
  • Burrows constructed by rats provide as refuge for venomous creatures. For instance, serpents.
  • These inflict harm on books, clothing, food, leather items, doors, and other materials due to their nibbling behavior.
  • It serves as a vector host for rat fleas that disseminate the plague bacterium.