Final answer:
The exoskeleton is a thick, hard protective layer made primarily of chitin, not thin fibrous elements, and it provides a surface for muscle attachment while protecting the organism. Correct option is false.
Step-by-step explanation:
The statement in the student's question is false. The exoskeleton is not composed of thin, fibrous elements but rather consists of a relatively thick, hard encasement that covers the surface of organisms such as arthropods, including insects, crabs, and lobsters.
This exoskeleton is made mostly of chitin, a polysaccharide derivative of glucose, which is strong and flexible. It is often further reinforced with minerals such as calcium carbonate. The exoskeleton is acellular, and since it does not grow with the organism, arthropods must periodically shed by molting. Muscles attach to the exoskeleton via ingrowths called apodemes, functioning as attachment sites for movement, comparable to tendons in animals with endoskeletons.