(a) Define a nutrient. Name four important nutrients present in our food.
(b) What are the various types of heterotrophic nutrition?

(a) A nutrient is defined as a substance that an organism obtains from its surroundings and uses it as a source of energy or for the biosynthesis of its body constituents (like tissues and organs).

The four important nutrients present in our food are carbohydrates, fats, proteins, and mineral salts.

(b) The various types of Heterotrophic nutrition are:

(i) Saprotrophic nutrition.