Which of the following is an accurate description of a round worm's skeleton? A) They have an endoskeleton composed of cartilage. B) They have a rigid exoskeleton that must be periodically shed. C) They have a flexible exoskeleton called a cuticle.
Answer (1)
A roundworm's skeleton is best described by option C: They have a flexible exoskeleton called a cuticle.
Roundworms, also known as nematodes, are a type of invertebrate with a simple body structure. They do not have a true skeleton made of bone or cartilage like the endoskeletons found in vertebrates. Instead, roundworms possess a protective outer layer called a cuticle.
The cuticle is a flexible exoskeleton made primarily of collagen and other proteins. It provides a sturdy yet flexible barrier that offers structural support and protection from the external environment. The cuticle is semi-rigid, which helps the worm maintain its shape while allowing for movement.
Because the cuticle does not grow with the worm, it must be periodically shed and replaced as the worm grows – a process known as molting or ecdysis. This shedding allows the roundworm to increase in size and continue its development.
This adaptive feature of having a flexible exoskeleton is crucial for roundworms as it aids in their survival and ability to thrive in various environments.
