Question

Phytoplankton are only found at the surface of ocean waters because . A. they feed on tiny organisms living at the surface. . . B. they are an important food source to surface-dwelling marine organisms. . . C. they require sunlight to carry out photosynthesis. . . D. they cannot withstand the colder temperatures of deep water. .

Answer 1

The answer to is

C. The require sunlight to carry out photosynthesis.

Answer 2

Phytoplankton are only found at the surface of ocean waters because they require sunlight to carry out photosynthesis. There are two main classes of phytoplankton and they are dinoflagellates and diatoms. Phytoplankton provide food for a variety of creatures in the sea such as snails, shrimp, jellyfish and whales.