AP BIOLOGY

Detailed explanation-1: -The jejunum is the middle part of the small intestine, between the duodenum and ileum. Most digestion and nutrient absorption takes place in the jejunum.

Detailed explanation-2: -The small intestine is good for absorption since it has a large inner surface area. This is formed due to the plicae circulares which project many tiny finger-like structures of tissue called villi.

Detailed explanation-3: -The ileum is the last and longest section of the small intestine. Here the walls of the small intestine begin to thin and narrow, and blood supply is reduced. Food spends the most time in the ileum, where the most water and nutrients are absorbed.