$(a)$ Name the extensively coiled structure of the alimentary canal.
$(b)$ Compare the length of the small intestine in herbivores and carnivores.

(N/A) The extensively coiled structure of the alimentary canal is the small intestine.
$(b)$ The length of the small intestine varies in different animals depending on the type of food they consume. Herbivores,which feed on grass,require a longer small intestine to facilitate the digestion of cellulose. In contrast,carnivores possess a shorter small intestine because meat is comparatively easier to digest.