Question

multiple choice question
what are tests (in regard to ocean sediments)?

the fecal pellets of microscopic organisms
the inorganic cell walls of phytoplankton and zooplankton
the skeletons of ocean mammals
ocean density currents

Explanation:

To solve this, we analyze each option:

• Option 1: Fecal pellets are not "tests" in ocean sediment context.
• Option 2: Tests are the inorganic (often calcareous or siliceous) cell walls/skeletons of phytoplankton (like diatoms, coccolithophores) and zooplankton (like foraminifera, radiolaria), so this matches.
• Option 3: Ocean mammals' skeletons are not referred to as tests in ocean sediment terms.
• Option 4: Density currents are not related to tests.

Answer:

B. The inorganic cell walls of phytoplankton and zooplankton (assuming the second option is labeled B; adjust label as per original question's numbering if different, but based on content, this is the correct description of "tests" in ocean sediments).