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.

Answer 1

The whale is heterotrophic.

Explanation: Whales obtain energy by eating other organisms (heterotrophy), whereas phytoplankton perform photosynthesis (autotrophy). Whales, as animals, do not have cell walls; many phytoplankton (algae, diatoms) do.