Question

Assertion :Blood of Cockroach is colourless with no respiratory pigment. Reason: Respiration in Cockroach occurs through diffusion in haemolymph.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is C Assertion is correct but Reason is incorrect

The colourless blood or haemolymph of cockroach has a clear plasma and numerous white corpuscles called haemocytes. Being devoid of any respiratory pigment, it does not serve for gaseous exchange. Its plasma contains about 70% water. Rest of it is composed of amino acids, uric acid, proteins, sugar, fats, and salts of sodium, potassium, calcium and magnesium. Transportation of these materials in different parts of the body is the main function of haemolymph. In all terrestrial animals, like cockroaches, every tissue of the body is in direct contact with atmospheric air for gaseous exchange. A complicated system of numerous shiny, transparent and branched air tubes or tracheae is found in the haemocoel cavity. Atmospheric air enters into and escapes out from this system through ten pairs of slit-like apertures called stigmata or spiracles, located on the lateral side of the body.

So, the correct answer is 'Assertion is correct but the reason is incorrect'.