The part of the intestine where most digestion and nutrient absorption occur.

The inner layer of the wall of a pollen grain or spore.

Located within or administered into a muscle.

Occurring within a single species.

Competition between members of the same species for resources.

Internal physiological or genetic factors influencing an organism’s function or development.

The incorporation of genetic material from one species into the gene pool of another through hybridization and backcrossing.

A non-coding segment of DNA within a gene that is removed during RNA processing.

A person who tends to focus on internal thoughts and feelings rather than seeking external stimulation; also used in biology to describe inward-turning structures.

In geology, the movement of magma into pre-existing rock formations.