Protostomes Lecture Review

A series of vocabulary flashcards covering key terms and concepts from a lecture on protostomes and related phyla.

Protostomes

Organisms characterized by developmental stages in which the mouth forms before the anus.

Ecdysozoa

A clade of protostomes that undergo ecdysis, or molting.

Lophotrochozoa

A clade of protostomes that have lophophore or trochophore larvae.

Ecdysis

The process of molting in which an organism sheds its exoskeleton.

Phylum Nematoda

Also known as roundworms, organisms characterized by bilateral symmetry and a thick cuticle.

Caenorhabditis elegans

A model organism in genetic and developmental studies, composed of a fixed number of cells.

Dioecious

Referring to species that have distinct male and female individuals.

Stylet

A piercing organ near the mouth of nematodes used for feeding.

Phylum Tardigrada

Commonly known as water bears, these organisms can survive extreme conditions and were studied for their resilience.

Phylum Arthropoda

The most successful animal phylum, known for body segmentation, a rigid exoskeleton made of chitin, and jointed appendages.

Hemocoel

A body cavity found in arthropods where blood flows freely.

Malpighian tubules

Excretory structures in terrestrial arthropods that aids in waste removal.

Trachea

A respiratory system structure in arthropods that branches into smaller tubes for gas exchange.

Compound eyes

Visual organs in many arthropods composed of multiple units called ommatidia.

Rhynchocoel

A fluid-filled coelomic cavity found in phylum Nemertea.

Ocelli

Simple eyes found in some arthropods that can distinguish light from darkness.

Asexual reproduction

A mode of reproduction involving a single organism, often through fragmentation in species like nemerteans.

Echinodermata

A phylum of marine animals which includes starfish and sea urchins.