the study of the stages before birth.

the process by which a cell takes in material by folding the cell membrane around the material.

an organelle in which parts of the cell membrane are made and some proteins are chemically modified.

catalyst that speed up the rates of biochemical reactions by lowering the activation energy.

cell that contain a nucleus.

the process by which a cell releases large amounts of material using folds in the cell membrane.

the death of all individuals with a species.

the movement of specific molecules across the membrane via protein channels embedded in the cell membrane.

anaerobic reactions, which produce energy but not as efficiently as do aerobic reactions.

union of male and female gametes to form a zygote.

the theory that organisms best suited to their environments are most likely to succeed.

long whiplike structures that aid in the movement of some cells.

the preserved remains of ancient organisms.

provides evidence that life on Earth has changed over time.

a mutation where a nitrogenous base is added or deleted.