science quiz

Homologous

Structures

Parts of different species

that are similar in structure

because they came from a

common ancestor, but they

might have different

functions.

Analogous

Structures

Parts of different species

that have a similar function

(what they do) but evolved

from different ancestors and

have different internal

structures.

vestigial structures

A structure or organ in an

organism that has become

reduced or non-functional

over time. It is a leftover

from an ancestor that did

use the structure.

common ancestor

An ancient organism from

which two or more different

species evolved. It sits at the

point where their evolutionary

family trees meet.

adaptive structures

A trait or structure that has

been modified by natural

selection to help an organism

survive and reproduce better

in its specific environment.