Question

1. Are radiolarians zooplankton or phytoplankton?

Answer 1

I believe the answer is zooplankton
Hope this helps you

Answer 2

Radiolaria are holoplanktonic protozoa and form part of the zooplankton, they are non-motile (except when flagella-bearing reproductive swarmers are produced) but contain buoyancy enhancing structures; they may be solitary or colonial.