Why is respiration in insect called direct?

1

(a)

The insects have network of tubes (tracheal system). The cells of the tracheal system exchange O₂/CO₂ directly with the air by the spiracles present insect's body.

How is negative pressure breathing helpful for mammals?

1

(a)

It allows the mammals to eat and breathe at the same time.

Why is it advisable to do nasal breathing rather than mouth breathing?

1

(a)

Nasal breathing is advisable because it is healthier as the air inhaled gets filtered through the hairs present inside the nose, so cleaner air reaches to the lungs.

What is the role of oxyhaemoglobin after the release of molecular oxygen in the tissue?

1

(a)

Combines with carbon dioxide to form carbamino-haemoglobin.

Differentiate between haemoglobin of human and earthworm?

1

(a)

Human: RBC; Earthworm : dissolved in plasma( location based).

Why cartilaginous rings on trachea are C-shaped?

1

(a)

For shock absorption and expansion / contraction while breathing in / out.

Define partial pressure of gases?

1

(a)

Pressure exerted by the molecules of a gas in a mixture of gases.

If deoxygenated blood in the lungs has PCO₂= 46 mmHg, what should be the alveolar PCO₂,for CO₂ to diffuse into alveoli from blood.

1

(a)

Less than 46mmHg.

What is chloride shift? What is its importance?

1

(a)

Diffusion of Cl- from blood plasma into RBC. To maintain ionic balance & electrochemical neutrality.

Arrange in increasing order of their volume: TV, IRV, RV, ERV, VC,TLC.

1

(a)

TV<ERV<RV<IRV<VC<TLC.