Question

zoology review
porifera, cnidaria

1. many cnidarians have two distinct life stages (or body styles) called:
2. because sponges stay in one place all their lives and feed off of food particle in the water, they are considered:
3. nematocysts do what?
4. what is the function of collar cells in porifera?
5. what is the function of amoebocytes in porifera?
6. the cnidarians inner layer of tissue is specialized for:
7. the outer cell layer of a cnidarian is called the:
8. what characteristics are associated only with cnidarians?
9. scyphozoans spend most of their lives in this stage
10. the class of cnidarians that typically live only as polyps is the
11. which cnidarian sensory structure is specialized to detect gravity?
12. cnidarians are diploblastic, meaning they have what?
13. cnidarians that typically build a skeleton of calcium carbonate belong to the class known as the
14. cnidarians are dimorphic, meaning they have
15. the formation of a true head region where the sensory organs are located is known as;
16. sponges have sharp structures that protect and support their bodies called;
17. corals exist in a symbiotic relationship with
18. a hydra exhibits what kind of symmetry?

Explanation:

1. Cnidarians have two alternating body forms in their life cycle.
2. Organisms that stay fixed in one location and filter food from water are defined this way.
3. Nematocysts are specialized stinging structures unique to cnidarians.
4. Collar cells in sponges create water flow and capture food particles.
5. Amoebocytes in sponges handle nutrient transport, digestion, and structure building.
6. The inner tissue layer of cnidarians is responsible for digesting food.
7. The outer cell layer of cnidarians forms the protective outer surface.
8. This feature is a specialized stinging cell structure unique to the phylum.
9. Scyphozoans (jellyfish) spend most of their life as the free-swimming stage.
10. This cnidarian class includes organisms like corals and anemones that stay in polyp form.
11. This sensory structure helps cnidarians orient themselves relative to gravity.
12. Diploblastic refers to having two primary tissue layers in embryonic development.
13. This cnidarian class builds calcium carbonate skeletons that form reefs.
14. Dimorphism refers to having two distinct body forms in the life cycle.
15. This term describes the evolutionary development of a head with sensory organs.
16. These sharp, structural elements make up the sponge's supportive skeleton.
17. Corals have a mutualistic relationship with photosynthetic protists.
18. Hydra have symmetry where body parts radiate from a central axis.

Answer:

1. Polyp and medusa
2. Sessile filter feeders
3. Inject venom/sting to capture prey and defend
4. Create water current and trap food particles
5. Transport nutrients, digest food, and produce skeletal structures
6. Digestion (extracellular and intracellular)
7. Epidermis
8. Nematocysts (stinging cells)
9. Medusa stage
10. Anthozoa
11. Statocysts
12. Two germ layers: ectoderm and endoderm
13. Anthozoa
14. Two distinct body forms (polyp and medusa)
15. Cephalization
16. Spicules
17. Zooxanthellae (photosynthetic dinoflagellates)
18. Radial symmetry