What is the function of cuticle in nematodes?

The cuticle in nematodes is a vital structure that serves primarily to protect the organism and provide resistance to host digestive enzymes. As nematodes are often found in various environments, including those within hosts, the cuticle acts as a barrier against the harsh conditions they may encounter. This protective layer prevents digestion by the host's enzymes, allowing the nematode to survive and thrive in locations such as the intestinal tract of its host.

The structure of the cuticle is made of a tough, flexible material called collagen, which is vital for the nematode's survival in hostile environments. It also plays a role in maintaining the nematode's shape and preventing desiccation, enabling it to endure the different physiological conditions it may face.

In contrast, while the other functions listed are important in their own right, they do not accurately describe the primary role of the cuticle in nematodes. For instance, locomotion is primarily mediated by muscles beneath the cuticle, not by the cuticle itself. Reproduction involves different structures and processes that are not related to the cuticle, and nutrient absorption occurs primarily through the body wall, distinct from the protective functions of the cuticle.