Question

Why is the length of small intestine so large?

Answer 1

the small intestine is long because digestion, absorption and assimilation is all together a long and difficult process. So a lot of enzymes in different parts of the intestine which helps in digestion of different proteins,carbohydrates etc...

Answer 2

Herbivores eating grass need a longer small intestine to allow the cellulose to be digested. Whereas Meat is easier to digest, hence carnivores like tiger have shorter small intestine.