Unit 3: Porifera & Cnidaria

Front

What are the main characteristics of Porifera?

Back

Porifera, or sponges, are multicellular organisms that lack true tissues and organ systems. They reproduce both asexually and sexually and are primarily filter feeders.

Front

What is the function of the spongocoel in sponges?

Back

The spongocoel is the central cavity of the sponge where water is filtered and circulated.

Front

What are spicules in the context of sponges?

Back

Spicules are hard structures that form the rigid skeletal framework of sponges, providing support and protection.

Front

What are the two main body forms of Cnidarians?

Back

The two main body forms of Cnidarians are the medusa (free-swimming) and the polyp (sessile) stages.

Front

What type of symmetry do Cnidarians exhibit?

Back

Cnidarians exhibit radial symmetry, meaning their body parts are arranged around a central axis.

Front

What is the role of cnidocytes in Cnidarians?

Back

Cnidocytes are specialized cells in Cnidarians that contain nematocysts, which are used for capturing prey and defense.

Front

What is the difference between a polyp and a medusa?

Back

A polyp is a cylindrical, sessile form of Cnidarians, while a medusa is a bell-shaped, free-swimming form.

Front

What do Cnidarians lack compared to more complex organisms?

Back

Cnidarians lack true organs; they have tissues but no specialized organs.

Front

How do sponges obtain their food?

Back

Sponges obtain food through filter feeding, where they draw in water and trap food particles using specialized cells called choanocytes.

Front

What is the significance of the mesohyl in sponges?

Back

The mesohyl is a gelatinous matrix within sponges that provides structural support and contains cells involved in various functions.