Chapter 13 (Gaseous Exchange) F.Sc 1st Year Biology Short Questions

Write two factors which affect the transport of oxygen in blood.

  • When carbon dioxide pressure increases, the oxygen tension decreases, the capacity of haemoglobin to hold oxygen becomes less.
  • Rise in temperature also causes a decrease in the oxygen-carrying capacity of blood, e.g., in the increased muscular activity.
  • As the pH of the blood declines, the amount of oxygen bound to haemoglobin also declines.

Differentiate between photorespiration and photosynthesis.

In photorespiration, oxygen is fixed while in photosynthesis carbon dioxide is used.[the_ad id=”17144″]

How exchange of gases takes place in Hydra?

Exchange of gases i.e., intake of oxygen and removal of carbon dioxide, occurs through the entire general body surface wherever it is in contact with water. Diffusion of oxygen in and carbon dioxide out also occurs in cells lining the digestive cavity.

What factors keep the skin of earthworm moist?

Skin is always kept moist by the secretion of epidermal mucous gland cells and also by coelomic fluid passing through the dorsal pores.

How exhalation (expiration) and inhalation (inspiration) occur in Cockroach?

When abdomen expands the first four pairs of spiracles are open. Air enters these spiracles. Then abdomen contracts, the anterior four pairs of spiracles close and posterior six pairs of spiracles open. This forces air through the tubes and eventually out of the body. In this way exhalation and inhalation takes place at the same time in different regions of the body.

Name the structures involved in the gaseous exchange in frog.

Lungs, skin, buccal cavity or chamber.

What is the role of diaphragm in inspiration and expiration?

The shape of the diaphragm is more domelike when its muscles are relaxed and inspiration occurs. On the other hand when the muscles of the diaphragm contract its shape becomes less domelike and expiration occurs.

Write at least two different states of Co, transportation in blood.

  • About 70% carbon dioxide is carried as bicarbonate ion combined with sodium in the plasma.
  • Some of carbon dioxide (about 20%) is carried as carboxyhaemoglobin.

Give two symptoms of emphysema.

  • Constant coughing reduces the absorbing surface of the lung
  • Least exertion makes him breathless and exhausted
  • Lips or fingernails turn blue or gray with exertion

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