NEET BIOLOGY

Detailed explanation-1: -Solution : The ileum of a mammal is well adapted for the absorption of digested food as: <br> (i) It is very long, which provides more surface area for the absorption. <br> (ii) The inner lining of the ileum has great number of villi, which enormously increase the inner surface area for absorption.

Detailed explanation-2: -The lining is highly folded to form microscopic finger-like projections called villi which increase the surface area to help with absorption.

Detailed explanation-3: -Adaptation of the ileum for absorption: Large surface area – due to being long and folded. Thin – digested food doesn’t have to travel far to reach the blood. Permeable – digested food can pass through easily. Good blood supply – to maintain the concentration gradient for diffusion between the ileum and bloodstream.

Detailed explanation-4: -Villi are finger-like projections that increase the surface area of the small intestine. Q. Microvilli increase the surface area of the small intestine which helps in absorption.

Detailed explanation-5: -On the surface of each columnar cell there are about 600 very fine projections called microvilli that further increase the absorptive area of each villus. Villi of the intestine move in swaying, contracting motions. These movements are believed to increase the flow of blood and lymph and to enhance absorption.