Vitamins regulate various metabolic pathways.

Earthworm feeds upon dead organic matter present in the mud. Hence, it is detritivore.

It shows both intracellular and extracellular absorption.

Palate helps in retaining food in the buccal cavity and proper mastication.

These are storage structures of a cockroach. The haemocoel consists of a large number of fat bodies which are fat cells having fat globules, protein granules and glycogen.

Food is grinded in gizzard. Its wall contains 6 longitudinal folds. The cuticle of these folds becomes thicker to form 6 teeth like structures which aid in grinding.

These are leaf-like papillae which are not developed in human tongue and are distributed at the sides of the base of the tongue of rabbit etc.

It secures and holds the tongue inside the mouth by attaching it to mandibles, hyoid by muscles and to the floor of the buccal cavity.

The taste buds for bitter taste are present at the back of the tongue.

Humans have 8 incisors in permanent denture.

This is dental formula for permanent teeth of humans.

It is filled with soft pulp made up of blood capillaries and nerve fibers, therefore this region is sensitive to pain.

These are chisel shaped with sharp cutting edges, used in cutting food.

These organisms can utilise energy released during the chemical reaction occurring in them. Sulphur and iron bacteria are chemoautotrophic.

Leeches are blood sucking animals.