Question

sponge knowledge check
cells at the base of choanocytes capture plankton & start digesting it.
amoebocyte
spicule
flagellum
collar

Explanation:

Amoebocytes are mobile cells in sponges that can capture and digest food like plankton. Spicules are structural elements, flagellum is a part of choanocytes for water movement, and collar is also part of choanocytes (collar cells) for filtering. Only amoebocyte fits the role of capturing and starting digestion of plankton.

Answer:

amoebocyte