Introduction to Animal Diversity

A collection of vocabulary terms and definitions related to the introduction of animal diversity, focusing on characteristics, body plans, and classifications.

Eukaryotic

Organisms whose cells contain a nucleus and organelles.

Multicellular

Organisms composed of multiple cells.

Heterotrophic

Organisms that obtain their food by consuming other organisms.

Invertebrates

Animals that lack a backbone.

Vertebrates

Animals that possess a backbone.

Symmetry

The balanced arrangement of body parts around a central axis.

Asymmetry

No symmetry; an irregular shape with no balanced halves.

Radial Symmetry

Body plan where parts are arranged around a central axis.

Bilateral Symmetry

Body plan where the left and right sides are mirror images.

Coelom

A fluid-filled body cavity that provides space for organ development.

Acoelomate

Animals that do not have a body cavity.

Pseudocoelomate

Animals with a body cavity that is not completely lined with mesoderm.

Eucoelomate

Animals with a true coelom that is completely lined with mesoderm.

Diploblastic

Organisms that develop from two embryonic layers: ectoderm and endoderm.

Triploblastic

Organisms that develop from three embryonic layers: ectoderm, mesoderm, and endoderm.

Archenteron

The initial digestive bubble formed during gastrulation.

Blastopore

The opening formed during the early development of the embryo.

Protostomes

Organisms where the blastopore develops into the mouth.

Deuterostomes

Organisms where the blastopore develops into the anus.

Mesoderm

The middle embryonic layer that develops into muscles and other structures.

Ectoderm

The outer embryonic layer that develops into the skin and nervous system.

Endoderm

The inner embryonic layer that develops into the digestive tract.