Biology Chapter on Protostomes

An animal whose blastopore develops into the mouth, and whose body cavity develops from the mesoderm splitting.

An animal whose blastopore develops into the anus, and whose body cavity develops from outpocketing of the archenteron.

A major lineage of protostomes characterized by a lophophore (feeding structure) or a trochophore larva.

A horseshoe-shaped crown of tentacles used for filter feeding in some protostomes, like brachiopods and bryozoans.

A free-swimming larval stage characteristic of some protostomes, including annelids and molluscs.

A phylum of lophotrochozoan protostomes, including flatworms, that are bilaterally symmetrical, acoelomate, and often parasitic.

A phylum of lophotrochozoan protostomes, including segmented worms like earthworms and leeches, characterized by a segmented body and a closed circulatory system.

A shared derived character, or trait, that is unique to a particular clade.

A group of animals that shed their outer layer (cuticle or exoskeleton) to grow. This process is known as ecdysis.

Roundworms that are often microscopic, found in diverse habitats, and can be free-living or parasitic. They have a pseudocoelom body cavity.

A body cavity that is not completely lined by mesoderm. It is filled with fluid and helps with hydrostatic pressure.

The largest animal phylum with organisms like insects, spiders, crabs, and more. They have a hard exoskeleton, segmented body, and jointed appendages.

A hard, external covering that protects and supports the body of arthropods. It is made of chitin and is shed during molting.

A body divided into repeating units called segments, allowing for flexibility and specialized functions.

Limbs that are connected to the body by a joint, allowing for movement and specialized function.

The process where arthropods shed their exoskeleton to allow for growth. This involves shedding the old exoskeleton and growing a new one.