Question

Assertion: In cockroach respiratory gases directly comes in contact with the various organs of the body.

Reason: Cockroaches do not have respiratory pigment.

(a) Both A and R are true and R is the correct explanation of A.

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

The correct option is: (a)

Explanation:

The blood of cockroach, also called as haemolymph is a mobile connective tissue composed of corpuscles and a colourless fluid, the plasma. It does not contain any respiratory pigment and therefore plays no role in respiration. 

The respiratory system consists of a network of trachea, that open through 10 pairs of small holes called spiracles present on the lateral side of the body. Thin branching tubes carry oxygen from the air to all the parts. The opening of the spiracles is reguiated by the sphincters. Exchange of gases take place at the tracheoles by diffusion.