Question

1. which of the following cells are part of the epidermis?

a. epitheliomuscular
b. nematocyst
c. gland cells
d. all of these

1. the cnidarian group is more advanced than the porifera because__________;

a. cnidaria have tissues
b. all cnidarian move
c. all cnidarian have nematocyst
d. all of these

1. the fertilized egg of a jellyfish is called a polyp.

a. true
b. false

1. the layer of a jelly fish that makes up the gastrodermis is formed from the _____________.

a. mesoderm
b. endoderm
c. ectoderm
d. none of these

Explanation:

1. For cnidarians (the group these cell types relate to), epitheliomuscular cells, nematocysts (specialized stinging cells in epidermal cells), and gland cells are all components of the epidermis.
2. Porifera (sponges) are at the cellular level of organization with no true tissues, while Cnidaria have true tissue layers. Not all cnidarians move (e.g., some polyps are sessile), and while nematocysts are a cnidarian trait, the key advanced feature is tissue development.
3. A jellyfish's fertilized egg develops into a planula larva first, which then matures into a polyp. The fertilized egg itself is not a polyp.
4. Cnidarians are diploblastic; the gastrodermis (inner layer) develops from the endoderm, while the epidermis develops from the ectoderm.

Answer:

1. d. all of these
2. a. Cnidaria have tissues
3. b. false
4. b. endoderm