Question

The respiratory system in human beings consists of a passage way for the fresh air to

flow from outside to the lungs and for the foul air to return from the lungs to the

exterior. Lungs cannot expand or contract of their own. It is brought about by specific

muscles. The muscles bring about alternate expansion and contraction of thoracic cavity

wherein lungs lie. Breathing involves exchange of gases between the air in alveoli and in

the blood capillaries and at the tissue level by simple diffusion.Energy in the case of higher plants and animals is obtained by

a) Breathing

b) Tissue respiration

c) Organ respiration

d) Digestion of food

(ii) Lactic acid production has occurred in the athlete while running in the 400 m race.

Which of the following processes explains this event?

a) Aerobic respiration

b) Anaerobic respiration

c) Fermentation

d) Breathing

(iii) Which muscles bring the contraction and expansion of lungs?

a) Diaphragm muscles

b) External intercostals muscles

c) Both a & b

d) Neither a nor b​

Answer 1

Answer:

I.(a) breathing

ii.(b)Anaerobic respiration

iii.(a) diaphragm muscles