Question

A: Chitinous exoskeleton is a characteristic feature of arthropods.
R: It allows diffusion of water vapour from the atmosphere to the body.
A. Both assertion & reason are true and the reason is the correct explanation of the assertion
B. Both assertion & Reason are true but the reason is not the correct explanation of the assertion
C. Assertion is true statement but reason is false
D. Both assertion and reason are false statements

Answer 1

Hint: This question is from the animal kingdom. First, we need to understand about the chitinous exoskeleton and in which animal it was found. Also need to know about arthropods and their features. After that, I need to compare both statements to get the final answer.

Complete step-by-step answer:

Chitin, sometimes known as chitinous, is a primary component of the exoskeletons, or exterior skeletons, of many arthropods, such as insects, spiders, and crustaceans. Because these creatures lack an internal skeleton, exoskeletons formed of this robust and hard material support and preserve their sensitive soft tissues. Chitin is water-impermeable and prevents water vapour from diffusing from the atmosphere to the body or vice versa.
Arthropods have an exoskeleton, paired jointed appendages, and a segmented body. Members are found in a variety of habitats, ranging from terrestrial to marine environments. Arthropods (e.g., cockroaches, termites, and wasps) have a chitinous exoskeleton, whereas molluscs have a calcareous shell (gastropods). (For example, snails and slugs).

Features of arthropods:

1) The body is segmented, triploblastic, and bilaterally symmetrical.
2) They are organized at the organ system level.
3) The body is divided into three sections: the head, the thorax, and the abdomen.
4) Their bodies have jointed appendages that aid in locomotion.
5) The coelomic cavity is blood-filled.
6) They have a free-flowing circulatory system.
7) A pair of compound eyes can be found on the head.
8) Chitin is used to make the exoskeleton.

So, option C is the correct answer.

Note: The assertion is correct; a chitinous exoskeleton is a distinguishing feature of arthropods. Because chitin is impermeable to water, it does not allow water vapour diffusion from the atmosphere to the body or vice versa. Thus, the reason is wrong.