Overview of Animal Diversity

Flashcards summarizing key concepts related to animal diversity, evolutionary links, and developmental processes.

Choanoflagellates

Unicellular protists that are the evolutionary link to animals, likely ancestors to animals more than 700 million years ago.

Multicellular Heterotrophs

Animals are defined as multicellular heterotrophs that ingest and digest their food internally.

Collagen

An extracellular structural protein abundant in animal tissues, providing support and structure.

Eumetazoa

A group within Metazoa characterized by having true tissues, emerged around 680 million years ago.

Pluripotent Stem Cells

Cells that have the ability to differentiate into any type of cell in the body; key in early embryonic development.

Hox Genes

Unique to animals, these genes produce transcription factors that help establish body plans and segmentation related to appendage locations.

Coelom

A body cavity present in most triploblastic organisms, derived from mesoderm, providing cushioning and space for organ development.

Protostome

An organism in which the mouth forms from the blastopore during embryonic development.

Deuterostome

An organism in which the anus forms from the blastopore during embryonic development.

Embryonic Development

The process of fertilized eggs undergoing cleavage, gastrulation, and formation of germ layers to develop into mature organisms.

Radial Symmetry

A body plan in which body parts are arranged around a central axis.

Bilateral Symmetry

A body plan in which the left and right sides are mirror images; typical in triploblastic organisms.

Metamorphosis

The developmental process in which an organism transforms from a larval stage to an adult form.

Acoelomate

An organism that lacks a body cavity, typical in flatworms.

Pseudocoelomate

An organism that has a body cavity that is not derived from mesoderm.

Diploblastic

Organisms with two germ layers: ectoderm and endoderm, such as cnidarians.

Triploblastic

Organisms with three germ layers: ectoderm, endoderm, and mesoderm, typical in most animals.