Animal Evolution, Diversity, and Behavior

These flashcards cover key vocabulary related to animal evolution, diversity, and behavior, providing definitions and explanations of important concepts.

Invertebrate

An animal that lacks a backbone or vertebral column.

Chordate

An animal that has at least one stage of its life with a hollow nerve cord, notochord, a tail, and pharyngeal pouches.

Vertebrate

An animal that has a backbone.

Feedback Inhibition

A process in which a stimulus produces a response that opposes the original stimulus.

Radial Symmetry

A body plan where any number of imaginary planes drawn through the center of the body can divide it into equal halves.

Bilateral Symmetry

A body plan where a single imaginary line divides the body into left and right sides that are mirror images.

Coelom

A body cavity filled with mesoderm.

Cephalization

The concentration of sense organs and nerve cells at the anterior end of an animal.

Epithelial tissue

Covers both the inside and outside of body surfaces.

Muscle tissue

Organized to move the body.

Nervous tissue

Sends messages.

Endoderm

The germ layer that lines the digestive tract and most of the respiratory system.

Mesoderm

The germ layer that forms muscles and most of the circulatory, reproductive, and excretory systems.

Ectoderm

The germ layer that forms the nervous system and outer layer of the skin.

Behavior

A response to stimuli in the environment.

Society

A group of animals of the same species that interact closely and often cooperate.

Kin Selection

A theory that helping relatives can improve an individual’s evolutionary fitness.

Communication

The passing of information from one individual to another.

Language

A system that combines sounds, symbols, and gestures according to rules about sequence and meaning.

Habituation

The simplest type of learning where an animal stops responding to a stimulus that neither rewards nor harms it.

Insight Learning

The most complex type of learning, applying something recently learned to a new situation.

Classical Conditioning

A learning process where a stimulus produces a response through association.

Operant Conditioning

A learning process where an animal learns to behave a certain way to receive a reward or avoid punishment.

Open Circulatory System

A circulatory system where blood is only partially contained within vessels and flows freely into body cavities.

Closed Circulatory System

A circulatory system where blood circulates entirely within vessels.

Atrium

The upper chamber of the heart that receives blood.

Ventricle

The lower chamber of the heart that pumps blood out to the body.

Rumen

A chamber in the stomach of cows and similar animals where symbiotic bacteria digest cellulose.

Filter Feeders

Animals that use gills or structures to strain food from water.

Detritivores

Animals that eat decaying organic matter and microorganisms.

Herbivores

Animals that eat plants or algae.

Carnivores

Animals that eat other animals.

Parasitic Symbiosis

A relationship where parasites live on or in a host, feeding on its tissues.

Mutualistic Symbiosis

A relationship where both organisms benefit.

Gills

Feathery structures for gas exchange with water.

Alveoli

Tiny air sacs in lungs where gas exchange occurs.

Excretion

The process by which metabolic wastes are eliminated from the body.

Kidney

An organ that removes waste and excess water from the blood.

Nephridium

Excretory structure in annelids (like earthworms) that filters body fluids.

Malpighian Tubule

A structure in most terrestrial arthropods that concentrates uric acid and adds it to digestive waste.