Question

In cockroach, the excretory product is
A. Ammonia
B. Uric acid
C. Urea
D. Both A and C

Answer 1

Hint: Animals may be classified into three categories based on their excretory products. Ammonotelic animals are creatures whose primary excrement is ammonia, and ammonotelism is the method of eliminating ammonia. Uricotelic animals are organisms whose primary excreta is uric acid, and uricotelism is the process of uric acid removal. Ureotelic animals have urea as their primary excreta, and the process of urea removal is known as ureotelism.

Complete answer:
Let us solve this question by analyzing each of the options.
Option:A – Ammonia is a toxic excretory product and is usually excreted by organisms which inhabit aqueous environment where they can excrete ammonia by keeping it diluted. However, Cockroaches are terrestrial organisms.
So, Option: A is not correct.
Option:B – Uric acid is the least poisonous and the least water soluble of the acids. As a result, it is the primary excreta in species that save water. Insects, land snails, reptiles, and birds, are some examples of uricotelic animals. Cockroach being an insect also excretes uric acid.
So, Option:B is correct.
Option:C – Generally, urea is not excreted by cockroaches.
So, Option:C is incorrect.
Option:D – Since Cockroaches excrete uric acid. So, Both A and C cannot be correct.
So, Option:D is incorrect.

Hence option B. Uric acid is the correct answer.

Note:
Cockroaches contain Malpighian tubules, which extract wastes from their internal liquids; the liquids are recirculated, and the wastes are expelled in solid or semi-solid form, along with excess nitrogen. A uricotelic organism excretes uric acid or its salts after deamination. Cockroaches excrete uric acid in a concentrated urine which is a pasty waste or a pellet. The main urine discharged from the Malpighian tubules must pass via the rectum before exiting the insect's body, where it undergoes substantial change in its composition.