Possession of thin membrane enables a tapeworm to

Analyze the question: It asks what function a tapeworm's thin membrane (its thin body wall or tegument) serves.

Concept: Tapeworms are endoparasites that live in the host's intestine. They have no mouth and no digestive system of their own. The host has already digested the food in the intestine, so the tapeworm only needs to take in the soluble nutrients. It does this through its thin, permeable body surface, which gives a large surface area for diffusion and absorption.

Evaluating the options:

• A. Fasten to the intestinal wall. This is the job of the scolex, which carries hooks and suckers. It has nothing to do with a thin membrane. ❌
• B. Lay numerous eggs. Eggs are produced in the reproductive organs of the proglottids. The membrane is not involved. ❌
• C. Absorb digested food from the host's intestine. This matches the function of the thin body surface, which absorbs the host's already-digested food directly. ✅
• D. Shield themselves with anti-enzymes. Tapeworms do produce anti-enzymes, but these are secreted chemicals, not a function of the thin membrane. ❌

Answer: The thin membrane lets the tapeworm absorb digested food from the host's intestine into its own body.

Exam tip: Link each tapeworm feature to its job:

• Scolex with hooks and suckers → attachment
• Thin body surface → absorption of food
• Proglottids → reproduction
• Anti-enzyme secretion → protection from digestion