Question

question 21
what is the purpose of choanocytes in a sponge?
all of these choices.
they hunt prey for the sponge to eat.
they regulate an internal current of water with beating flagella.
they are the means of sponge mobility.

Explanation:

Choanocytes, also known as collar cells, are specialized cells in sponges. Their flagella beat to create a water current that helps in filter - feeding (which can be considered as a form of 'hunting' prey in a sense as they capture food particles from the water). The water current they create is an internal water current. Sponges are mostly sessile (not mobile), so the option about mobility is incorrect. Since the functions of creating a water current (which aids in feeding as food is captured from the water) are valid for choanocytes, and the first option “All of these choices” would be correct if the other valid options are considered. The option “They hunt prey for the sponge to eat” is related to the feeding mechanism (as food is captured from the water current they create), and “They regulate an internal current of water with beating flagella” is a direct function of choanocytes.

Answer:

All of these choices.