CHAPTER 12: PORIFERA

Question 1

Metazoans

Answer 1

Multicelled animals

Question 2

choanocytes

Answer 2

a flagellated cell with a collar of protoplasm at the base of the flagellum

filter feeders

Question 3

spicules

Answer 3

structural elements found in most sponges.

Sponge spicules are made of calcium carbonate or silica.

Question 4

dermal ostia

Answer 4

small incurrent pores,

Question 5

osculum

Answer 5

an excretory structure in the living sponge, a large opening to the outside through which the current of water exits after passing through the spongocoel

Question 6

prosopyles

Answer 6

a pore through which water is drawn from the outside into one of the saclike chambers formed by the evagination of the body wall.

Question 7

apopyles

Answer 7

one of the openings by which the water passes out of a radial canal or flagellated chamber of a sponge.

Question 8

mesohyl

Answer 8

gelatinous matrix

Question 9

parenchymula

Answer 9

The free-swimming larva of most sponges