What are sponges?
- filter feeders (they filter food out of the water as it passes through their bodies)
- adults are sessile (don't move)
What are sponges made of?
Sponges are made of spongin (tough and elastic) and spicules (sharp, glasslike, used for support)
How do sponges reproduce?
Both sexually (sperm and egg cells combine) and asexually (budding)
What are cnidarians?
They have tentacles that surround their mouths, shoot out stining cells (nematocysts)
What are some examples of cnidarians?
Jellyfish, hydra, anemone, and coral
What are two kinds of cnidarian body forms?
- polyp-sessile (can somersault)
- medusa-free swimming (floats)
Explain cnidarian reproduction.
- Polyps reproduce asexually (budding)
- Medusas reproduce sexually (sperm+egg)
What are flatworms (Plathelminthes)?
- Simplest worm
- long flattened bodies
- 3 layers of tissues organized into organ systems
- Can move to search for food
- most are parasites (ex. tapeworm. fluke)
What are roundworms (Nematods)?
- the most widespread animal on Earth
- body is a tube within a tube
- digestive tract has two openings (food enters mouth, waste exits via anus)
- can be decomposers, predators, or parasites
- Example- heartworm
What are Segmented Worms (annelids)?
- Body = repeating segments or rings
- contain nerve cells, blood vessels. digestive tract, and coelom (internal body space)
- closed circulatory system (blood is carried through blood vessels)
- complete digestive system with 2 body openings
What are some examples of segmented worms?
Earthworms, leeches, marine worms
What is setae?
Bristles that help segmented worms move