Question

Identify the parts marked "1" and "2" in the figure below. Also, mention the reason for the folds seen in the structure. [3 MARKS]

Answer 1

Labelling - 1 Mark each
Reason for folds: 1 Mark

1 - Villi
2 - Microvilli

Villi exist in the small intestine, and the main function of the small intestine is absorption. Absorption is directly dependent on surface area. So to increase the surface area, the internal surface of the intestinal wall is folded onto itself creating villi.
Again the surface of each villus is convoluted in a similar fashion and the resulting microscopic structures are called as microvilli (brush border).