Animal Diversity and Evolution

These flashcards cover key terms and definitions related to the lecture on animal diversity and evolution.

Animal Diversity

The variety of animal species and their evolutionary history.

Evolution

The process by which different species of organisms develop and diversify from earlier forms.

Multicellularity

A condition of being composed of many cells, characteristic of animals.

Heterotrophic metabolism

The process of obtaining energy by consuming other organisms.

Internal digestion

A process where food is broken down inside a specialized cavity in the organism.

Body symmetry

The balanced arrangement of body parts around a central axis.

Coelom

A fluid-filled body cavity that is completely surrounded by mesoderm tissue.

Acoelomate

An animal that lacks a coelom or body cavity, such as flatworms.

Pseudocoelomate

An animal with a pseudocoelom, a body cavity not completely lined with mesoderm.

Coelomate

An animal that possesses a coelom, such as earthworms.

Segmentation

The division of an animal's body into repetitive segments, aiding in movement and specialization.

Nervous system

A network that processes sensory information and coordinates movement.

Cnidarians

A group of animals that includes jellyfish, sea anemones, and corals.

Nematocysts

Specialized cells in cnidarians that contain toxins used for capturing prey.

Bilaterians

Animals that exhibit bilateral symmetry, including most animal phyla.

Protostomes

Animals in which the blastopore develops into the mouth during embryonic development.

Deuterostomes

Animals in which the blastopore develops into the anus during embryonic development.

Lophotrochozoans

A major group of protostomes characterized by a lophophore orTrochophore larva.

Ecdysozoans

A major group of protostomes that grow by molting their cuticle.

Arthropods

The largest group of animals, characterized by exoskeletons and jointed appendages.

Chelicerates

A group of arthropods characterized by mouthparts called chelicerae.

Mandibulates

A group of arthropods characterized by mandibles for chewing.

Hexapods

Insects and their relatives, characterized by three pairs of legs.

Pterygote insects

The first flying animals, which evolved wings.