PORIFERA & CNIDARIA

These flashcards cover key vocabulary terms related to the phyla Porifera and Cnidaria, providing definitions and critical descriptions based on the lecture content.

Choanocytes

Unique flagellated cells in sponges responsible for creating water currents and capturing food through phagocytosis.

Spicules

Structural elements in sponges, made of calcium carbonate or silicon dioxide, providing support.

Mesohyl

The gelatinous region that separates the two layers of cells in sponges.

Radial Symmetry

A form of symmetry where body parts are arranged around a central axis, common in cnidarians.

Diploblastic

Organisms that develop from two embryonic cell layers: ectoderm and endoderm.

Gastrulation

A developmental process that forms gut layers; absent in sponges.

Amoebocytes

Totipotent cells in the mesohyl of sponges that digest food, transport nutrients, and can differentiate into various cell types.

Gemmules

Internal buds formed during asexual reproduction in sponges, allowing them to survive adverse conditions.

Nematocysts

Stinging cells in cnidarians, used for capturing prey and defense.

Eumetazoa

A clade of animals characterized by true tissues and germ layers.

Hydrozoa

A class of Medusozoa that includes both polyp and medusa forms, often colonial.

Anthozoa

A class of cnidarians that exist only as polyps, including corals and sea anemones.

Osculum

The large opening in sponges through which water exits after being filtered.

Planula

The free-swimming ciliated larva stage in the life cycle of cnidarians.