Which feature of a villus is NOT an adaptation for absorption?
- A. A dense network of blood capillaries
- B. A single layer of epithelial cells covering it
- C. Microvilli on the free surface of its cells
- D. A thick covering of muscle around each villus
Explanation
A villus is adapted by being thin walled, richly supplied with blood and lymph and covered in microvilli, all of which shorten the diffusion path or enlarge the surface. A thick muscular coat would do the opposite by lengthening the distance nutrients must travel. Muscle lies in the wall of the intestine as a whole, where it produces peristalsis, not around individual villi.
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