When the myelin sheath of nerve cells is damaged, nerve transmission slows down.

This seed has a well-developed coleoptile.

The leaf sheath of this plant is very long.

This insect's elytron has a very beautiful pattern.

I go to the gym every day to build my muscles.

This river is three long.

Oocytes play an important role in the reproduction of organisms.

Olfactory cells play an important role in allowing us to sense smells.

Olfactory cells play a role in sensing smells in the nose.

Macrophages play a role in taking in and breaking down foreign substances in the body.