Sponges

Sponges are simple aquatic animals that belong to the phylum Porifera. They are characterized by their porous bodies and lack of true tissues and organs. Sponges are filter feeders, meaning they obtain food and oxygen by filtering water through their bodies.

Study Guide Questions:

1. What phylum do sponges belong to?
2. How do sponges obtain food and oxygen?
3. What is the structure of a sponge's body?

Cnidarians

Cnidarians are a diverse group of animals that include jellyfish, corals, and sea anemones. They are characterized by the presence of stinging cells called cnidocytes, which they use for defense and capturing prey. Cnidarians have radial symmetry and a simple nerve net for coordinating their movements.

Study Guide Questions:

1. What are some examples of cnidarians?
2. What is the function of cnidocytes?
3. What type of symmetry do cnidarians exhibit?

Worms

Worms are a diverse group of invertebrate animals that belong to various phyla, including Annelida (segmented worms) and Platyhelminthes (flatworms). They exhibit bilateral symmetry and have well-developed organ systems. Worms play important roles in ecosystems as decomposers and food sources for other animals.

Study Guide Questions:

1. What are the main phyla of worms?
2. What type of symmetry do worms exhibit?
3. What roles do worms play in ecosystems?