Which of the following statements are true about respiration ?
(i) during inhalation, ribs move inward and diaphragm is raised.
(ii) the gaseous exchange takes place in the alveoli.
(iii) haemoglobin has greater affinity for carbon dioxide than oxygen.
(iv) alveoli increase surface area for the exchange of gases
(a) (i) and (iv)
(b) (ii) and (iii)
(c) (i) and (iii)
(d) (ii) and (iv)

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Solution

Option (d) (ii) and (iv)

The air sacs (alveoli)are at the end points of the respiratory tract and have a very large total surface area.They have moist, thin walls (just one cell thick) they have a lot of tiny blood vessels called capillaries.Exchange of gases between the air sacs and their surrounding capillary blood vessels take place here.. Oxygen diffuses from the air sac into the blood. Carbon dioxide diffuses from the blood into the air sac.

There are over 700 million alveoli in the lungs, covering a total surface area of about 70 m², which is a considerably larger surface area relative to volume. The large surface area makes gas exchange with the bloodstream more efficient.

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Question 14
Which of the following statement(s) is (are) true about respiration?

(i) During inhalation, ribs move inward and the diaphragm is raised.
(ii) In the alveoli, exchange of gases takes place i.e., oxygen from alveolar air diffuses into blood and carbon dioxide from the blood into the alveolar air.
(iii) Haemoglobin has a greater affinity for carbon dioxide than oxygen.
(iv) Alveoli increase surface area for exchange of gases.

(a) (i) and (iv)
(b) (ii) and(iii)
(c) (i) and (iii)
(d) (ii) and (iv)

Q. Which of the following statement(s) is (are) true about respiration?

(i) During inhalation, ribs move inward and the diaphragm is raised.
(ii) In the alveoli, exchange of gases takes place i.e., oxygen from alveolar air diffuses into blood and carbon dioxide from the blood into the alveolar air.
(iii) Haemoglobin has a greater affinity for carbon dioxide than oxygen.
(iv) Alveoli increase surface area for exchange of gases.

Q. Which of the following statements are true about respiration?

(i) In plants, respiration happens during the night time only, while photosynthesis happens during the day.

(ii) In humans, the exchange of gases takes place in the alveoli.

(iii) Haemoglobin has a greater affinity for oxygen than carbon dioxide.

(iv) Aquatic organisms use the oxygen in the surrounding atmosphere for respiration.

[0.8 Mark]

Q. Consider the following four statements (i - iv) and select the correct option stating which ones are true (T) and which ones are false (F).
(i) Formation of oxyhaemoglobin occurs at the alveolar surface.
(ii) During gaseous exchange the gases diffuse from high partial pressure to low partial pressure.
(iii) Carbon dioxide cannot be transported by haemoglobin.
(iv) Earthworm respires through parapodia.

Which of the following statements are correct ?
(i) pyruvate can be converted into ethanol and carbon dioxide by yeast
(ii) fermentation takes place in the case of aerobic bacteria
(iii) fermentation takes place in mitochondria
(iv) fermentation is a form of anaerobic respiration
(a) (i) and (iii)
(b) (ii) and (iv)
(c) (i) and (iv)
(d) (ii) and (iii)

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