Important Questions For Class 10 Biology Respiration

Important Questions For Class 10 Biology Respiration  Respiration

Question 1. What is the function of the trachea? Why do the walls not collapse even when there is less air in them?
Answer:

• The trachea is a cylindrical conduit for air from the pharynx to the lungs
• The lining epithelium captures dust particles and bacteria, expelling them forth.
• The trachea remains patent despite lower air pressure owing to the presence of C-shaped cartilaginous rings.

Question 2. Give reason:

1. Fine hair and mucus are present in the nasal passage.
2. Rings of cartilage are present in the throat.

Answer:

1. Fine hair and mucus present in nasal passages trap dust particles and microbes from inspired air.
2. Rings of cartilage prevent the collapsing of the trachea when air pressure is low.

Question 3. Mention the shape of guard cells and write their constituents.
Answer:

In most plants, guard cells are bean-shaped in outline. They are joined at their ends but are free on inner thick-walled regions. The outer walls are thin-walled. Guard cells are nucleated. They have several small chloroplasts and small-sized vacuoles.

Question 4. Why is diffusion not sufficient to meet the oxygen requirement of all the cells in multicellular organisms?
Answer:

Diffusion may transpire if each cell in the body is encased by intercellular gaps that are linked to the atmosphere via pores. This is not possible in mammals. Consequently, they possess a transport system to deliver oxygen to all body cells.

Respiration Class 10 Important Questions

Question 5.

1. Why are cramps caused in our muscles during sudden excess activity?
2. Name the type of respiration that takes place in Yeast during fermentation.

Answer:

1. Muscles get fatigued during sudden excess activity due to the accumulation of lactic acid caused by anaerobic respiration. This causes cramps.
2. Anaerobic respiration yields ethyl alcohol and carbon dioxide.

Question 6. Write two different ways in which glucose is oxidised to provide energy in the human body. Write the products formed in each case.
Answer:

The two ways in which glucose is oxidised are aerobic and anaerobic. In aerobic respiration, oxygen functions as a terminal oxidant. It produces CO₂ and water.

In anaerobic respiration that occurs in skeletal muscles, oxygen is not used. Glucose is broken down to produce lactic acid.

Question 7. Give a reason for the following:

1. The glottis is covered by epiglottis.
2. Lung alveoli are covered with blood capillaries.
3. The wall of the trachea is supported by cartilage rings.

Answer:

1. The epiglottis covers the glottis during swallowing to prevent entry of food and water into the trachea.
2. Lung alveoli are covered by blood capillaries because they function as the respiratory surface of the lungs. There is a gaseous exchange between blood and alveolar air with oxygen entering blood and carbon dioxide entering alveolar air.
3. Cartilage rings provide support to the trachea and keep it open for free passage of air.

Question 8. List three characteristics of lungs which make them an efficient respiratory surface.
Answer:

1. Lungs have a large number of microscopic alveoli which create a huge respiratory surface area of about 80 m².
2. Alveoli are invested with blood capillaries for rapid exchange of gases.
3. The passageway of air is non-collapsible being supported by cartilaginous rings in broader branches and surfactant in narrow areas.
4. Airtight location of lungs in the thoracic cavity where rise or fall in pressure causes exhalation and inhalation respectively.

Class 10 Biology Respiration Questions And Answers

Question 9.

1. The breathing cycle is rhythmic whereas the exchange of gases is continuous. Justify the statement.
2. Why is breathing through the mouth harmful?

Answer:

1. The whole of the air is not drained out during exhalation. A large amount of air remains in the lungs. The same is called residual volume. It allows the continued exchange of gases.
2. Breathing through the mouth is harmful as:
   1. It allows dust particles and microbes to enter the buccal cavity and lungs causing irritation and infection,
   2. Dry, hot or cold air produces irritation to the whole respiratory system.

Question 10. Mention the special features of nasal breathing that make it a safer process.
Answer:

• Filtration of particulate matter by nasal cilia.
• Elimination of dust and microorganisms by the mucus in the nasal cavities.
• Expelling trapped dust and germs by ciliary action.
• Destruction of microorganisms by lysosome in the nasal epithelium.
• Humidification of breathed air by the moist nasal epithelium.
• Air conditioning refers to the process of adjusting the temperature of inhaled air to match that of the body, facilitated by the blood capillaries located in the nasal passage

Question 11. Explain how glucose is broken down in the absence or shortage of oxygen.
Answer:

Glucose is first broken down to form two molecules of pyruvate, two molecules each of NADH₂ and ATP.

1. In the absence or shortage of oxygen, pyruvate is reduced by NADH₂ by two methods
2. Formation of ethyl alcohol and evolution of CO₂ as in yeast.
3. Formation of lactic acid as in skeletal muscles and lactic acid bacteria.

In both cases, a molecule of glucose yields a small amount of energy (2ATP molecules) as compared to aerobic respiration (38 ATP molecules).

Difference Between Aerobic And Anaerobic Respiration Class 10

Question 12.

1. In the process of respiration, state the functions of alveoli.
2. The rate of breathing in aquatic organisms is much faster than that in terrestrial organisms. Give reasons.
3. Complete the following pathway showing the breakdown of glucose

Answer:

1. Alveoli. Exchange of gases.
2. Aquatic Organisms. The rate of breathing is faster in aquatic organisms in order to obtain required oxygen from water which is very low as compared to air.
3. Pyruvate
4. Carbon dioxide.