Overview of Animal Characteristics and Development

These flashcards provide vocabulary terms and definitions related to the characteristics, development, and classification of animals.

Multicellular eukaryotes

Organisms composed of multiple cells with complex structures, containing a defined nucleus.

Heterotrophic

Organisms that obtain their food by consuming other living things.

Blastula

An early embryonic stage characterized by a hollow ball of cells.

Blastopore

A specific region on an early embryo's surface that typically becomes either the mouth or anus.

Germ layers

Special groups of cells in embryos that develop into different tissues and organs.

Asymmetry

A condition where an organism cannot be divided into equal parts.

Bilateral symmetry

A form of symmetry where an organism can be divided into mirrored halves along one plane.

Radial symmetry

A type of symmetry where the body is organized around a central axis.

Protostomes

Animals in which the blastopore develops into the mouth.

Deuterostomes

Animals in which the blastopore develops into the anus.

Ectoderm

The outer germ layer that develops into dermal and neural tissues.

Endoderm

The inner germ layer that develops into the gut lining.

Mesoderm

The middle germ layer that develops into connective tissues such as muscle and blood.

Analogous traits

Traits that serve similar functions but do not share a common evolutionary origin.

Homologous traits

Traits that are similar due to shared ancestry, even if they serve different functions.

Phylum

A higher taxonomic category that groups organisms based on major body plans and morphological features.