Question

Phytoplankton, shown on the left in the image below, are microscopic organisms that can be found in freshwater and salt water environments. They perform photosynthesis to get energy and act as an important food source for larger organisms, such as the whale that is shown on the right.

Phytoplankton A large whale.

Which characteristic describes the whale but not its food source, the phytoplankton?
The whale is heterotrophic.
The whale has cell walls.
The whale is unicellular.
The whale is a prokaryote.

Answer 1

The whale is heterotrophic.

Explanation: Whales obtain energy by eating other organisms (heterotrophs), while phytoplankton perform photosynthesis and are autotrophs. The other choices (cell walls, unicellular, prokaryote) do not correctly distinguish whales from phytoplankton.