NEET Biology – Mineral Nutrition In Plants Notes

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NEET Biology Mineral Nutrition In Plants

The mineral elements that are essential for the plant body are mostly absorbed by roots. Only Carbon, Oxygen and Hydrogen are obtained from air and water. The utilization of various elements absorbed by plants in growth and development is called mineral nutrition.

NEET Biology Mineral Nutrition In Plants Essentiality Of An Element

The essentiality of an element can be judged by ash analysis, solution culture or solid medium culture. The earliest culture solution was prepared by Sachs.

NEET Biology Mineral Nutrition In Plants Functions Of Minerals

The minerals perform several functions such as the construction of the plant body, maintenance of osmotic pressure, permeability, pH, performing catalytic function, imparting toxicity and balancing function.

NEET Biology Mineral Nutrition In Plants Physiological Role of Essential Elements

  • Each important element executes a unique array of functions that are not entirely replicated by other essential elements.
  • An element is crucial for the survival of a higher green plant for one or more of the following four reasons.
  • It may provide a nutritive function as a constituent of one or more primary classes of plant compounds.
  • It may also play a catalytic role, either as an enzyme activator or as an essential component of an enzyme.
  • It may operate as three non-catalytic ‘metallo-biomolecules’ or as a free ion.

Macro-elements. A scientific approach to the role of mineral elements started with Sachs and Knop in 1850. It has been proved that carbon, hydrogen, oxygen, sulfur, phosphorus, calcium, magnesium, and iron are essential for the growth and development of plants.

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These elements are required in large amounts and without them normal metabolism is retarded. These elements are referred to as Macro-elements or Major elements because of the relatively large quantities in which they are needed for plant life.

Neet Biology Mineral Nutrition Notes Pdf

Micro-elements. Plants also require other elements in small quantities. These elements are not involved in the composition of plants but are present in traces. They help as catalysts in various metabolic processes.

These elements which are required in small quantities or traces are called micro-elements or trace elements. Some important micro-nutrients are Manganese, Zinc, Boron, Copper Molybdenum and Chlorine.

NEET Biology Mineral Nutrition In Plants Minerals Critical Concentration

  1. The need of individual plants for any particular element is normally defined in terms of -critical concentration. This is the concentration of that nutrient, measured in the tissue, 1st below the level which gives maximum growth (Epstein, 1972).
  2. In the absence of any essential element, the plant will be expected to exhibit certain morphological and biochemical symptoms of that deficiency. In some cases, the deficiency symptoms will clearly reflect the functional role of that element (Hopkins, 1995)

NEET Biology Mineral Nutrition In Plants Minerals Other Elements

  1. Sodium. The importance of sodium for the growth of marine algae was first realised by Osterhout in 1906. It is also needed by blue-green algae for growth. In higher plants, it maintains the differential permeability of cytomembranes.
  2. It also participates in nitrogen metabolism. The C4  plants also require sodium. It may partially substitute for potassium in lower as well as higher plants.
  3. Silicon. It is present in grasses, sedges, rushes, equisetum, and several algal forms. Somnar, 1926 observed that it is essential for the growth of rice and millet whereas Lipman, 1938 discovered that it is necessary for the growth of sunflower and barley.
  4. Aluminium. It is found to improve the growth of several plants. On the other hand, many plants are known to possess sensitivity to aluminium toxicity.
  5. Cobalt. It is a component of vitamin B12  (Cyanocobalamin). A few blue-green algae and the bacterium Rbizobium, a symbiotic nitrogen-fixing bacteria of leguminous nodules also require cobalt
  6. Gallium. Steinberg, 1945-46 found that the fungus Aspergillus niger and Lenina minor need gallium for their growth.
  7. Selenium. Plants like Astragalus and Stanleya act as selenium indicators. They contain a high concentration of selenium.
  8. Iodine. Some marine algae like Laminaria accumulate iodine in huge amounts.
  9. Besides, gold is known to occur in Equisetum and vanadium is necessary for the growth of certain plants.

Mineral Nutrition in Plants Notes for NEET Biology

NEET Biology Mineral Nutrition In Plants Mineral Uptake By Plants

A plant obtains C2 H2 and O2 as CO7 are obtained from the atmosphere and water and the rest of the minerals are taken from the soil (solution mining). The absorption may occur through root hair Mycorrhizae or the mature part of the root.

  • The soils may be acidic having principal cation H+, or alkaline where Ca4-1″ predominates. Acidic soils are made alkaline by liming (cation exchange) and alkaline soil by adding sulphur becomes acidic.
  • This sulphur is oxidised to sulphuric acid by microbes.
  • The cell-to-cell movement of ions occurs through symplast and plasmodesmata. There may be pores of 7 A diameter in the plasma membrane. Besides, there are carrier proteins (permeases) in this membrane.
  • Dead membranes are more permeable than living. The membranes are more permeable to O7, N2 COT and other smaller molecules. The lipophilic molecules are more permeable than hydrophilic.
  • The ionic absorption has been regarded as an active process or passive. In the latter process, there is no expenditure of metabolic energy,
  • According to Hylmo, there is a mass flow of mineral ions into the root along with transpiration current. Many other workers believe that the mineral ions diffuse into the root along a concentration gradient.
  • The part of the plant cell or tissue that permits free diffusion is called outer space and the apparent volume accommodating these ions is apparent free space.
  • The facilitated diffusion occurs through protein channels. It is stereospecific and occurs up to the saturation limit. The ions are transported through carrier proteins,
  • The ion exchange hypothesis states that a particular ion is exchanged by a similar type of ion i.e., a cation by a cation and anion by an anion. It may occur by contact exchange or by the formation of carbonic acid.
  • The Donnan equilibrium is believed to be reached due to the presence of some diffusible or fixed zones. It explains the entry of ions against a concentration gradient,
  • There is ample evidence to believe in the active uptake of salts such as a faster rate of absorption, absorption against a concentration gradient, the correlation between rates of respiration and salt absorption, salt-induced respiration etc.
  • According to Van den Honert, the cation and anions are transported through separate carriers. They make a complex and release them into the cell enzymatically,
  • Lundegardh believes that the anions are transported across the membrane through a cytochrome pump whereas the cations are transported passively,
  • Many people think that in the transport of ions, ATP is used up. The hydrolysis of ATP causes the release of energy. The transport is mediated by ATP ase.
  • The movement of ions and carriers may occur in the same direction (symport carrier) or the opposite direction ( antiport carrier).
  • While Goldacre believes that contractile proteins act as carriers. IJennett-CJark considers that lecithin is the main carrier of ions across the membrane.
  • The process of salt absorption is influenced by many factors such as temperature, light, oxygen, and growth. pH and mineral interaction.

Essential Minerals In Plants Neet Notes

NEET Biology Mineral Nutrition In Plants Deficiency Symptoms Due To Mineral Deficiencies

  1. Chlorosis: Chlorophyll formation in leaf tissue is impaired due to mineral shortage or illness. It is sometimes referred to as a physiological disease, arising from deficiencies in certain minerals such as iron, magnesium, and nitrogen.
  2. Etiolation: Etiolation refers to the yellowing or whitening of green plant tissues. Etiolation is a physiological occurrence observed in green plants cultivated in the absence of light.
  3. Necrosis: Cellular and tissue necrosis.
  4. Impeded development: Plants do not achieve normal height and stay stunted.
  5. Abscission: Leaves, flowers, and fruit exhibit premature abscission in the fall.
  6. Mottling: Presence of verdant and non-verdant regions.
  7. Leaf Deformations: Abnormal leaf curling resulting from uneven growth is termed helotism. Heart rot in plants refers to the internal weakening or decomposition of tissues due to their breakdown.

NEET Biology Mineral Nutrition In Plants Special Modes Of Nutrition

  1. The plants which are dependent on sonic other sources for their nutritional requirements are called heterotrophic plants which can be placed into four groups depending upon the sources of food: Parasites, saprophytes, symbionts and insectivorous or carnivorous plants.
  2. Parasites are common among fungi and bacteria but less common among flowering plants. The angiospermic parasites are of two types: Partial parasites and total parasites or holopurnsites.
  3. The partial parasites are green and thus photosynthesize but they obtain water and minerals from their host through their haustoria which remain in contact only with the xylem of the host. 1 he partial parasites are of two types i.e.
  4. Partial stem parasites For example. Viscum (mistletoe), Loranthus and Arceuthobium. Arccuthobium minutissimum is the smallest green leafless parasite growing on Pinus excelsa. This plant is the minutest one among the dicots;
  5. Partial root parasites For example. Sanlalum album (sandalwood tree) and Tliesitim.
  6. The total parasites are non-green as they do not possess chlorophyll and hence derive their entire food from their host. Their haustoria communicates with both the xylem and phloem of the host.
  7. Saprophytes obtain their food from dead and decaying organic matter and are common among fungi and bacteria but less common among higher plants. The saprophytic flowering plants are Neottia (bird’s nest orchid), Monotropa (Indian pipe), Corallorhiza, Epipogon, etc.
  8. Almost all the saprophytic angiosperms possess mycorrhiza (an association of the fungus with the roots) and lack root hairs. Mycorrhiza may be ectotrophic as in Pinus, Belula, Monotropa (the Indian pipe), and Sarcodes; or endotrophic as in Neottia, Epipogon and Corallorhiza.
  9. Symbionts form symbiotic associations in which both the organisms of the association are benefited Example. lichens, and the association of legumes with Rhizobium (N2-fixing bacteria).
  10. Insectivorous plants are autotrophic so far as their carbohydrate nutrition is concerned but they are dependent on captured insects for their nitrogen requirement as they grow in N2-deficient soils (generally swamps and bogs). Thus, they are partly autotrophic and partly heterotrophic.
  11. About 200 species of angiosperms are insectivorous and some of them are :
  12. Drosera or Sundew – Its leaves possess glandular hairs called tentacles which secrete a sticky fluid containing digestive enzymes.
  13. Utricularia or bladderwort is an aquatic, free-floating, rootless plant with dissected leaves and some of the leaf lobes are modified into sac-like structures called bladders.
  14. Nitrogen And Nitrogen Metabolism.
  • Nitrogen is a highly inert gas. Most of the nitrogen exists in proteins and amino acids. However, it is also found in large quantities in nucleic acids, cytochromes, chlorophyll, vitamins, alkaloids etc.
  • It is not used directly and is found in fixed forms in combination with C2 H2O2 to constitute other compounds. Nitrogen plays an important role in metabolism, heredity, reproduction and growth. Nitrogen combines with oxygen and hydrogen to form nitrate (NO2), nitrite (NO2) and ammonium salts (NH2). Bacteria and blue-green algae can also fix atmospheric nitrogen.

Plant And Nutrition Special Modes Mineralof Nutrition In Plants Special Modes of Nutrition

  • Soil contains nitrogen in the form of nitrate, ammonium salts and organic nitrogenous compounds. Ammonia is absorbed by the plants directly. Urea and amino acids can be absorbed directly by the plants. Urea is first converted into ammonia by the action of the enzyme urease.

Important Contributors

  • Sachs, using a culture solution showed the essentiality of nitrogen for plant growth.
  • Jenny and Overstreet (1938) proposed ion-exchange theory.
  • Bulk flow or mass flow theory was given by Hylmo (1953) and later sup¬ported by Kramer (1956).
  • The study of mineral nutrition was carried out by Knop (1865).
  • Winogradsky (1891) discovered biological nitrogen
  • P.R. Stout and D.R. Hoagland proved that minerals transport are translocated in the plants through the xylem.
  • Aristotle (300 B.C.) thought that plants get their nutrients in organic form from the soil.
  • Theodore de Saussure (1804) proposed that nutrients are made available to the plants from soil.
  • T.H. Vanden-Honert (1936) proposed carrier-mediated uptake of ions.
  • Jenny and Overstreet (1938) proposed ion-exchange theory.
  • Goerick (1940) developed Hydroponics.
  • Lundegardh (1950) proposed the cytochrome pump theory of salt absorption.
  • Hylmo (1953) proposed mass flow theory.
  • Bennet Clark (1956) proposed protein-lecithin as a carrier.
  • The enzyme nitrogenase successively reduces N2 into diimide and hydrazine and finally to 2NH with the utilisation of ATP.
  1. NHN NH = NH→NHT – NHT→2NH4 
  2. Nitrogen Diimide Hydrazine Ammonium
  3. Hydrogen ions and electrons for the reduction process are provided by reduced ferredoxin.
  4. Nitrogenase acts only in anaerobic conditions and under aerobic conditions it undergoes irreversible damage.
  5. The enzyme nitrogenase requires ATP, Mg++, an electron source and anaerobic conditions for converting nitrogen to ammonia.
  6. Anaerobic condition in symbiotic nitrogen fixation is provided by leghaemoglobin present in root nodules.
  7. Haemoglobin is made up of four peptide chains while leghaemoglobin in root nodules is a single peptide chain.
  8. Leghaemoglobins are red colour haemoglobin-like pigments which absorb oxygen and protect enzymes from oxygen.
  9. Though nitrogen is present in abundance in the atmosphere but cannot be directly used. It is converted into nitrates and nitrites by certain nitrogen-fixing bacteria and cyanobacteria.
  10. Species of Rhizobium are associated symbiotically with nodules of nodulated tap roots of leguminous plants.
  • The di-nitrogen (N,) of the atmosphere is reduced to ammonia by the action of the enzyme nitrogenase in the presence of a reducing agent and energy currency ATP.
  • Nitrogen Fixation Requires Three Components.
  • Strong reducing agent
  • ATP to transfer hydrogen atoms to dinitrogen ami the (f/x) enzyme sj-stem.
  • The reducing agents (FAD) and ATP are provided by photosynthesis and respiration.
  • Ammonia is utilized by plants as nitrate which is absorbed with the help of enzymes nitrate reductase and nitrite reductase.
  • Ammonium ions are used for the synthesis of amino acids, proteins and other nitrog¬enous molecules of plants.
  • Reductive animation. It is the primary pathway of amino acid formation. It involves the incorporation of ammonia or ammonium ions into ketoglutaric acid to yield glutamic acid.
    n-ketoglutaric acid + NH, -MX-Iminoglutaric acid a-Iminoglutaric acid + NADH + H+ Glutamic acid + NAD
  • Transamination. It involves tyre transfer of the amino group (-NH,) of one amino acid to the carboxylic group of a keto acid. As far as 17 different amino acids can be synthesized from glutamic acid by transamination.
  • Eight protons and six electrons are required to reduce a molecule of nitrogen into two molecules of ammonium.

Previous Year Neet Questions On Mineral Nutrition

Hydrogen is used in the conversion of molecular nitrogen to ammonia.

NEET Biology Mineral Nutrition In Plants Minerals

  • The chemical substances that provide nourishment to living organisms are termed nutrients,
  • Mostly all plants obtain their inorganic nutrients from soil, water and atmosphere.
  • Some green plants supplement their nutritional requirements with parasitic and insectivorous habits, Out of 105 elements, plants require about 20 elements. <=S> Inorganic elements are essential for their normal growth and reproduction.
  • Some elements form structural components whereas others participate in metabolic reactions or act as cofactors for several enzymes.
  • Elements become essential constituents of proteins, carbohydrates, fats, nucleic acids etc. co Some of them serve as activators/cofactors for various enzymes.
  • Heterotrophic plants could be parasitic, saprophytic, symbionts and insectivorous.
  • Lichens, mycorrhizae etc. are examples of symbionts. CO Droserci, Utricularia and Nepenthes are examples of insectivorous plants.
  • The carbon of plants is derived from that of atmospheric carbon dioxide.
  • Deficiency of minerals results in disorders such as reduction in growth, chlorosis and necrosis, co The elements are absorbed through the root by active or pas¬sive absorption and transported through the xylem to other parts of the plant.
  • Plants absorb minerals in the form of ions from the soil, Absorption of minerals occurs mainly from the region of elongation in the root.
  • Outer space or apoplast includes cell walls and intercellular spaces.
  • Inner space or symplast is formed by protoplast and plasmodesmata.
  • Mineral ions enter into the apoplast by a passive process named diffusion.

The movement of ions from apoplast to symplast is by

  1. Passive absorption
  2. Active absorption

These are 

1. Passive ion absorption:

  • Passive ion absorption transpires along the concentration gradient without the expenditure of energy (ATP).
  • Theories explaining the passive absorption of minerals include
    1. Donnan equilibrium
    2. Ion exchange
    3. Mass flow hypothesis.
  • According to the Don equilibrium concept (proposed by Donnan 1911) fixed ions present on the inner surface of the plasma membrane disturb the ionic equilibrium (electrochemical) of the cell. Initially, the cell accumulates cations when fixed ions are present, followed by the diffusion of anions into the cell.
  • The ion exchange theory posited by Jenny and Overstreet involves the exchange of ions from root I P2 OH with soil ions, facilitated by carbonic acid generated from the dissolution of CO2 in water, which dissociates to produce fP and HCO2ions for the ion exchange process.
  • The movement of ions accompanying the movement of water owing to transpiration is termed mass low.

Active absorption:

The process of actively absorbing ions against their concentration gradient by utilizing energy is termed active absorption. Vandcn presented a carrier notion to elucidate active absorption.

NEET Biology Mineral Nutrition In Plants Quanta To Memory

  • The roots of plants absorb a large number of elements from the soil. But only a few of these are essential for plant life.
  • Sodium and Iodine which are essential for animals, are not required by most plants.
  • Micronutrients are as important as macronutrients in plant nutrition.
  • Among the micronutrients. Iron is required in much larger quantities.
  • Recent research has shown that in addition to the already established microelements, Cobalt, Vanadium, Silicon, and Nickel may be essential for certain plants.
  • Examples of electrophilic mycorrhiza are beech and oak.
  • An example of endotrophic mycorrhiza which shows fungus within the roots is Epigonon.
  • Loranthus and Viscum album are partial parasites.
  • Cusciita reflex is a total stem parasite
  • A few members of the family Orobanchaceae such as Orobanchc are total root parasites flourishing on the roots of tomato, potato, and brinjal.
  • Epigonon (orchids), Monotropa, and sarcodes are a few examples of saprophyte plants.
  • Excess of salts in soils leads to the development of plant indicators.
  • The most common free ion in the cells is K+.
  • Potassium is required for the activity of about 40 enzymes.
  • Interveinal chlorosis of young leaves is due to deficiency of Iron, while that in old leaves is due to deficiency of Mg.
  • Deficiency of Zn causes little leaf disease in cereals.
  • The plants growing in water or by solution culture technique are termed hydroponics or soilless culture.
  • Manganese is essential for the photolysis of water.
  • Prokaryotes absorb the element nitrogen in gaseous form.
  • Gold has been reported to occur in the stems of Equisetum
  • Na-EDTA is the disodium salt of ethylene diamine tetra acetic acid.
  • In plants growing in nitrogen-deficient soils, the older leaves become chlorotic first, because nitrogen from older leaves moves into younger leaves. Younger leaves show normal nitrogen as they receive it from older leaves.
  • The pungent smell of onion and garlic is due to sulphur compounds.
  • NPK are the critical elements.
  • NPK fertilizers contain nitrophosphate with potassium.
  • Nitrogen is translocated from roots as amides, amines and amino acids through the xylem. Phloem sap contains P-proteins as well as citrates and malates. The concentration of Ca++ in phloem sap is lower than in xylem.
  • The young leaves collect phosphorus and older leaves have calcium deposition. Iron is deposited along the veins and cobalt is in the hydathodes.
    Aeroponics is a system for growing plants with their roots bathed in the nutrient mist (a cloud of moisture in the air).

Macronutrients And Micronutrients In Plants Neet

NEET Biology Mineral Nutrition In Plants Questions From Competitive Examinations

Question 1. Inorganic nutrients are present in the soil as :

  1. Biomolecules
  2. Atoms
  3. Electrically charged ions
  4. Colloids.

Answer: 3. Electrically charged ions

Question 2. Clay and organic matter in the soil have negative charges. They attract positively charged ions like :

  1. Ca2+
  2. Mg2+
  3. K+
  4. All the above.

Answer: 4.  All the above.

Question 3. Which of the following is required by plants for the formation of ATP’?

  1. N, Ca
  2. N, Cu
  3. N, K
  4. N. Ca.

Answer: 1.  N, Ca

Question 4. Magnesium is an important component of:

  1. Chlorophyll
  2. Florigen
  3. Hacmoerythrin
  4. Enzyme.

Answer: 1.  Chlorophyll

Question 5. Plants use Zinc as :

  1. Zn
  2. Zn2+
  3. ZnSO4
  4. Zn(NO3)2.

Answer: 2. Zn2+

Question 6.’ Plants growing in urea sprayed but Mg deficient soil
will show:

  1. Deep green foliage
  2. Early flowering
  3. Yellowing of leaves
  4. Loss of pigmentation in petals.

Answer: 3. Yellowing of leaves

Question 7. ATP molecules combine with carrier molecules and allow passage of substances :

  1. No ATP is required
  2. Along concentration gradient
  3. Against concentration gradient
  4. Both (2) & (3).

Answer: 3. Against concentration gradient

Question 8. Enzyme first used for nitrogen fixation :

  1. Nitrogenase
  2. Nitroreductase
  3. Transferase
  4. Transaminase.

Answer: 1. Nitrogenase

Question 9. This is an insectivorous plant:

  1. Eichhornia
  2. Opuntia
  3. Crotolariadarsa
  4. Utricularia.

Answer: 4. Utricularia.

Macronutrients And Micronutrients In Plants Neet

Question 10. Which of the following is non-symbiotic?

  1. Azotobacter
  2. Nostoc
  3. Rliizobiwn
  4. None of the above.

Answer: 1. Azotobacter

Question 11. Trace elements in plants are:

  1. K
  2. P
  3. Zn
  4. S.

Answer: 3. Zn

Question 12. Which of the following elements is essential for nitrogen metabolism in plants?

  1. Iron
  2. Potassium
  3. Magnesium
  4. Molybdenum.

Answer: 4. Molybdenum

Question 13. Plants absorb nitrogen in the form of:

  1. Nitrate
  2. Nitrites
  3. Urea and NH3
  4. NH4.

Answer: 1. Nitrate

Question 14. Which element is located at the centre of the porphyrin ring in chlorophyll?

  1. Manganese
  2. Calcium
  3. Magnesium
  4. Potassium.

Answer: 3. Magnesium

Question 15. The major role of minor elements inside living organisms is to act as:

  1. Binder of cell structure
  2. Co-factors of enzymes
  3. Building blocks of important amino acids
  4. Constituent of hormones.

Answer: 2. Co-factors of enzymes

Question 16. Plants deficient in the element zinc, show its effect on the biosynthesis of plant growth hormones:

  1. Abscisic acid
  2. Auxin
  3. Cytokinin
  4. Ethylene.

Answer: 2. Auxin

Question 17. The most abundant element found in plants is :

  1. Carbon
  2. Nitrogen
  3. Iron
  4. Manganese.

Answer: 1. Carbon

Question 18. The movement of ions is usually called llux. The inward movement into cells is called :

  1. Efflux as an active process
  2. Influx as a passive process
  3. Influx as an active process
  4. Efflux as a passive process

Answer: 3. Influx as an active process

Symptoms Of Mineral Deficiency In Plants NEET Biology

Question 19. Molybdenum is obtained by plants and is a part of enzymes

  1. P – MO            Q – Nitrogenase
  2. P – MqO+22    Q – All enzymes
  3. P – Mq              Q – Nitrate reductase
  4. P – MqO+22    Q – Nitrogenase

Answer: 4. P – MqO+22    Q – Nitrogenase

Question 20. Which of the following is incorrect :

  1. Potassium plays an important role in the opening and closing of stomata.
  2. Some essential elements cannot alter the osmotic potential of a cell
  3. C, H, 0 and N are structural elements of the cell.
  4. In addition to 17 elements, there are some beneficial elements such as sodium, silicon, cobalt and sodium

Answer: 2.  Some essential elements cannot alter the osmotic potential of a cell

Question 21. Copper is the activator in enzymes:

  1. Carbonic anhydrase
  2. Tyrosinase
  3. Lactic dehydrogenase
  4. Tryptophanase.

Answer: 2. Tyrosinase

Question 22. If by radiation all the nitrogenase enzymes are inactivated, then there will be no :

  1. Conversion of nitrate to nitrite
  2. Fixation of atmospheric nitrogen
  3. Fixation of nitrogen in legumes
  4. Conversion of ammonium to nitrate.

Answer: 3. Fixation of nitrogen in legumes

Question 23. The ability of the Venus Flytrap to capture insects is due to :

  1. A passive process requiring no special ability on the part of the plant
  2. Chemical stimulation by the prey
  3. specialized “muscle-like” cells
  4. Rapid turgor pressure changes.

Answer: 4. Rapid turgor pressure changes.

Question 24. All of the following statements concerning the actinomycetous filamentous soil bacterium Frankia are correct EXCEPT that Frankia :

  1. Can induce root nodules on many plant species
  2. Cannot fix nitrogen in the free-living state
  3. Forms specialized vesicles in which the nitrogenase is protected from oxygen by a chemical barrier involving triterpene hopanoids
  4. Like Rhizobium, it usually Infects its host plant through root hair deformation and stimulates cell proliferation in the host’s cortex.

Answer: 2. Cannot fix nitrogen in the free-living state

Question 25. If there is a deficiency of micronutrients that not only affects the growth of plants but also vital functions such as photosynthetic and mitochondrial electron flow. Among the list given below, which group of three elements shall affect most, both photosynthetic and mitochondrial electron transport :

  1. Cu, Mn, Fe
  2. Ca, K, Na
  3. Mn, Co.
  4. Co, Ni, Mo

Answer: 1. Cu, Mn, Fe

Question 26. Prolonged liberal irrigation of agricultural fields is likely to create the problem of:

  1. Acidity
  2. Aridity
  3. Salinity
  4. Metal toxicity.

Answer: 3. Salinity

Question 27. The first stable product of fixation of atmospheric nitrogen in leguminous plants is:

  1. Ammonia
  2. NO3
  3. Glutamate
  4. NO2

Answer: 1. Ammonia

Question 28. Which is essential for root hair growth?

  1. Ca
  2. Zn
  3. MO
  4. S.

Answer: 1. Ca

Neet Biology Mineral Nutrition Notes Pdf

Question 29. Sulphur is an important nutrient for optimum growth and productivity in :

  1. Fibre crops
  2. Oilseed crops
  3. Pulse crops
  4. Cereals.

Answer: 3. Pulse crops

Question 30. Nitrogen fixation in root nodules of legumes is to :

  1. Convert atmospheric N2 to NH3
  2. Convert ammonia to nitrite
  3. Transport oxygen for the activity of nitrogenase
  4. Protect nitrogenase from oxygen.

Answer: 4. Protect nitrogenase from oxygen.

Question 31. Match the following and choose the correct combination from the options given.

Plant And Nutrition Special Modes Mineralof Nutrition In Plants Match The Following Question 31

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

Answer: 1. A-2 ,B-l ,C-4 ,D-3

Question 32. A plant requires magnesium for :

  1. Protein synthesis
  2. Chlorophyll synthesis
  3. Cell wall development
  4. Holding cells together.

Answer: 2. Chlorophyll synthesis

Question 33. Which one of the following elements is not an essential micronutrient for plant growth?

  1. Zn
  2. Cl
  3. Ca
  4. Mn.

Answer: 3. Ca

Question 34. Match the following mineral elements with their deficiency symptom and choose the correct option.

 

Plant And Nutrition Special Modes Mineralof Nutrition In Plants Match the Following Question 34

  1. A-3,  B-1,  C-5,  D-2,  E-4
  2. A-1,  B-4,  C-5,  D-3,  E-2
  3. A-3,  B-4,  C-5,  D-1,  E-2
  4. A-2,  B-3,  C-4,  D-1,  E-5
  5. A-4,  B-2,  C-1,  D-3,  E-5

Answer: 3.

Question 35. Which one of the following elements in plants is not remobilised?

  1. Phosphorus
  2. Calcium
  3. Potassium
  4. Sulphur.

Answer: 2. Calcium

Question 36. Nitrifying bacteria :

  1. Oxidize ammonia to nitrates
  2. Convert free nitrogen to nitrogen compounds
  3. Convert proteins into ammonia
  4. Reduce nitrates to free nitrogen.

Answer: 1.  Oxidize ammonia to nitrates

Question 37. The function of leghaemoglobin in the root nodules of legumes is:

  1. Inhibition of nitrogenase activity
  2. Oxygen removal
  3. Nodule differentiation
  4. Expression of if gene.

Answer: 2. Oxygen removal

Question 38. Which one of the following is the wrong statement?

  1. Root nodule-forming nitrogen fixers live as aerobes under free-living conditions.
  2. Phosphorus is a constituent of cell membranes, certain nucleic acids and all proteins.
  3. Nitrosomonas and Nitrobacter are chemoautotrophs
  4. Anabaena and Nostoc are capable of fixing nitrogen in a free-living state also.

Answer: 2.  Phosphorus is a constituent of cell membranes, certain nucleic acids and all proteins.

Question 39. Consider the following statements concerning facilitated transport.

  1. Requires ATP energy,
  2. Transport saturates
  3. Highly selective.
  4. Requires special membrane properties.
  5. Uphill transport.

Of The Above Statements

  1. 1, 2 and 3 are relevant but 4 and 5 are irrelevant
  2. 2, 3 and 5 are relevant but 1 and 4 are irrelevant
  3. 3, 4 and 5 are relevant but 1 and 2 are irrelevant
  4. 1, 4 and 5 are relevant but 2 and 3 are irrelevant
  5. 2, 3 and 4 are relevant but 1 and 5 are irrelevant.

Answer:  3. 3, 4 and 5 are relevant but 1 and 2 are irrelevant

Question 40. Find out the Correctly matched pair.

Plant And Nutrition Special Modes Mineralof Nutrition In Plants Find Out Correctly Question 40

Answer. 4. Manganese – Needed in the splitting of water to liberate oxygen during photosynthesis.

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