Animal Phyla and Body Plans

These flashcards cover the key terms and concepts related to various animal phyla, their characteristics, and basic biological concepts.

Porifera

The phylum of sponges, characterized by cell-level organization and no true tissues.

Choanocytes

Specialized cells in sponges that create a water current for filter feeding.

Asymmetry

A type of symmetry where there is no symmetry, as seen in sponges.

Cnidaria

The phylum that includes jellyfish and corals, characterized by tissue-level organization and radial symmetry.

Nematocysts

Stinging cells found in Cnidarians that are used to capture prey.

Acoelomate

An organism with no true body cavity, as seen in Platyhelminthes.

Pseudocoelomate

An organism with a body cavity that is partially lined with mesoderm, such as Nematodes.

Echinodermata

The phylum that includes sea stars and sand dollars, characterized by pentaradial symmetry.

Ecdysis

The process of molting that allows arthropods to grow.

Radula

A unique feeding structure in most Mollusks used for scraping food.

Hydrostatic skeleton

A type of skeleton found in Annelids and Nematodes that relies on fluid pressure.

Deuterostome development

A type of development where the blastopore becomes the anus; characteristic of Chordates and Echinoderms.

Diploblastic

Organisms with two germ layers (ectoderm and endoderm), like Cnidarians.

Triploblastic

Organisms with three germ layers (ectoderm, mesoderm, and endoderm).

Complete gut

A digestive system featuring a mouth and an anus; examples include Nematodes.

Incomplete gut

A digestive system with only one opening; seen in Platyhelminthes.

Exoskeleton

A rigid external covering for the body in some arthropods, made of chitin.

Eucoelomate

An organism with a true body cavity fully lined with mesoderm.

Notochord

A flexible rod-like structure found in Chordates.

Chordata

The phylum that includes vertebrates, characterized by having a notochord.

Segmentation

The division of the body into repetitive segments, first seen in Annelida.