Comparative Anatomy MS-LS4-3

NGSS

A hollow ball of cells of an animal embryo, it develops into a gastrula

Blastula

A hollow ball of cells of an animal embryo, it develops into a gastrula. Blastula. The blastula is an early stage in an embryo's development, where cells form a hollow sphere.

A biological classification system based on evolution from a shared ancestral line

Cladistics

A biological classification system based on evolution from a shared ancestral line. Cladistics. Cladistics is a way to organize living things by looking at their shared ancestors and evolution patterns, like building a family tree of species.

The most recent individual from which two or more species are descended

Common ancestor

The most recent individual from which two or more species are descended. Common ancestor. A common ancestor is an ancient organism that gave rise to different species through evolution.

when a male reproductive cell (sperm) joins with a female reproductive cell (egg)

Fertilization explained in an easy to understand way.

A similar structure in different species, like a whale fin, bat wing and your arm

Homologous structure

A similar structure in different species, like a whale fin, bat wing, and your arm. Homologous structure. Homologous structures are body parts in different species that have the same basic layout but may serve different functions, showing common ancestry.

A structure that was useful to an ancestor but is no longer functional, like the appendix

Vestigial structure

A structure that was useful to an ancestor but is no longer functional, like the appendix. Vestigial structure. A vestigial structure is a body part that has lost its original use over time because it is no longer needed for survival.

The cell formed when a sperm fertilizes an egg

Zygote

The cell formed when a sperm fertilizes an egg is called a zygote. In simple terms, a zygote is the first cell of a new organism that forms when an egg and sperm join together.