Animals

Multicellular heterotrophic eukaryotes

Organisms that consist of multiple cells, obtain food by consuming other organisms, and have complex cells with a nucleus.

Ingestion

The process of taking in food or nutrients into the body.

Diploid

A cell or organism that has two sets of chromosomes, one from each parent.

Meiosis

A type of cell division that reduces the chromosome number by half, resulting in the production of gametes.

Opisthokonts

A group of eukaryotes that includes animals, fungi, and some protists.

Choanoflagellates

Unicellular or colonial organisms that are the closest living relatives to animals.

Monophyletic group

A group of organisms that consists of a common ancestor and all its descendants.

Phylum Porifera

The phylum that includes sponges, which are simple multicellular organisms that lack true tissues.

Metazoans

Multicellular animals.

Spicules

Structural elements found in sponges, made of calcium carbonate, silica, or collagen.

Choanocytes

Specialized cells in sponges that create water flow and capture food particles.

Phylum Cnidaria

The phylum that includes jellies, corals, and anemones; characterized by radial symmetry.

Diploblasts

Animals that have two embryonic germ layers: endoderm and ectoderm.

Gastrovascular cavity

A digestive cavity with only one opening, serving both digestive and circulatory functions.

Cnidocytes

Stinging cells found in Cnidarians used for capturing prey.

Bilaterians

Animals with bilateral symmetry, having distinct dorsal and ventral sides.

Protostomes

A major clade of bilaterians where the blastopore becomes the mouth.

Deuterostomes

A major clade of bilaterians where the blastopore becomes the anus.

Phylum Platyhelminthes

The phylum that includes flatworms, characterized by being acoelomate triploblasts.

Acoelomate

An organism that lacks a body cavity.

Gastrovascular cavity in Platyhelminthes

A digestive cavity found in most flatworms that has one opening.

Phylum Mollusca

The phylum that includes clams, snails, and octopuses, characterized by a coelomate body plan.

Coelomate

An organism that possesses a true body cavity.

Mantle

A heavy fold of tissue in mollusks that covers the visceral mass and secretes the shell.

Class Gastropoda

A class of mollusks that includes slugs and snails, most of which have shells.

Class Cephalopoda

A class of mollusks that includes squids and octopuses, known for their modified foot as tentacles.

Class Bivalvia

A class of mollusks that includes clams and mussels, characterized by having two shells.

Phylum Annelida

The phylum that includes segmented worms, characterized by a segmented body.

Setae

Bristle-like structures found in many annelids that aid in movement.

Hydrostatic skeleton

A fluid-filled body cavity that provides support and enables movement in coelomates.

Parasitic flatworms

Flatworms that live off hosts, including tapeworms and flukes.

Free-living flatworms

Flatworms that are not parasites and inhabit various environments.

Mantle cavity

The space that encloses the respiratory organs in mollusks.

Aquatic and terrestrial habitats of mollusks

Mollusks can live in both water and on land.