Animal flashcards notebook LM

Blastula

A hollow, fluid-filled ball of cells that forms once an egg is fertilized by sperm.

Heterotrophs

Animals that cannot make their own food.

Porifera

The animal phylum that is an exception to the rule that all animals have bodies composed of tissues.

Radial symmetry

Symmetry around a central point, exhibited by members of the phylum Cnidaria.

Asymmetry

The term describes an animal that has no planes of symmetry.

Bilateral symmetry

Symmetry across the sagittal plane, exhibited by most animal phyla except Porifera and Cnidaria.

Coelom

A fluid-filled central body cavity that usually surrounds the gut.

Uninterrupted tissue

The area in flatworms from the gut to exterior that is composed of uninterrupted material.

Osculum

The large opening at the top of a sponge through which water flows out.

Flagella

Tiny structures within a sponge that create water currents for feeding.

Cnidaria

Phylum of animals that use stinging tentacles to capture prey.

Medusa stage

The adult, swimming stage of life in Cnidarians.

Polyp stage

The immature stage of life in Cnidarians that remains fixed to a surface.

Flatworms

Common name for animals in the phylum Platyhelminthes.

Coelom and blood circulation

Two major systems that flatworms (Platyhelminthes) lack.

Earthworms

Common name for the terrestrial members of the phylum Annelida.

Mollusca

Phylum that includes Gastropods, Bivalves, and Cephalopods.

Mantle

A fold of skin-like tissue in molluscs that usually secretes a shell.

Gastropods

Class of molluscs that includes snails and slugs.

Bivalves

Class of molluscs that includes oysters and clams.

Cephalopods

Class of molluscs that includes octopus and squid.

Roundworms

Common name for animals in the phylum Nematoda.

Arthropoda

Phylum that includes Uniramia, Chelicerata, and Crustacea.

Uniramia

Subphylum of Arthropoda that includes insects.

Chelicerata

Subphylum of Arthropoda that includes spiders and ticks.

Crustacea

Subphylum of Arthropoda that includes shrimp and lobsters.

Exoskeleton

The external skeleton found in arthropods.

Molting

The process by which arthropods shed their exoskeleton to grow.

Echinodermata

Phylum of animals such as sea stars and sea urchins, found in marine environments.

Notochord

A flexible rod that all chordates possess at some point in their lives.

Vertebrata

Subphylum of Chordata characterized by having a vertebral column.

Sexual reproduction

A reproductive process involving the fusion of eggs and sperm from two individuals.

Asexual reproduction

Reproduction that does not involve the fusion of sex cells.

Hermaphrodite

An animal that has both male and female reproductive organs.

Broadcast fertilization

The primitive ancestral method of egg fertilization in animals.

Amniotic shell

The evolutionary development in reptiles that allows eggs to be laid in dry environments.

Placental system

A system that evolved in mammals allowing fertilized eggs to develop inside the mother's body.

Organs

Complex bodily structures composed of several types of tissues.

Closed circulatory system

The type of circulatory system vertebrates have.

Open circulatory system

The type of circulatory system found in arthropods and small molluscs.

Endoskeleton

An internal skeleton found in some animals.

Hydrostatic skeleton

The third kind of skeleton found in animals, besides endoskeletons and exoskeletons.

Parasites

Members of phylum Platyhelminthes that live on or in other organisms.

Gill or lungs

Organs typically housed in the mantle cavity of a mollusc.

Sessile

A term describing adult sponges that are fixed in one spot.

Distinct body segmentation

Defining characteristic of the phylum Annelida, exemplified by earthworms.

Sea stars, sea urchins, sea cucumbers

Common names for members of phylum Echinodermata.