Give reasons/explain :

(a) Only animals require a digestive system and not plants.

(b) There are no enzymes to digest vitamins.

(c) Thorough chewing of food in mouth is helpful in digestion.

(d) Bile juice does not contain any enzyme but is still important in digestion.

(e) The inner layer of small intestine has a large number of finger-like projections called villi.

(a) Animals are heterotrophs. They obtain their nutrients by consuming organic matter, such as other organisms or plant material. Hence, they need a digestive system to break down complex molecules, such as proteins, carbohydrates, and lipids, into smaller, absorbable forms. In contrast, plants are autotrophs, capable of synthesizing their own food through photosynthesis. Hence, they don't require a digestive system.

(b) Vitamins do not need digestion. They are absorbed directly through the intestine wall.

(c) Chewing of food breaks the food into small particles which helps in easy digestion.

(d) Bile contains a lot of sodium bicarbonate which neutralises the acid content of the food received from the stomach and makes it alkaline so that pancreatic and intestinal enzymes can act on it.

(e) The villi enormously increase the inner surface area of the intestines which facilitates the absorption of digested food.