Consider the following kinds of organisms:1.Copepods2.Cyanobacteria3.Diatoms4.ForaminiferaWhich of the above are primary producers in the food chains of oceans?

1. A

   1 and 2

   1 and 2. Copepods are consumers, not primary producers.

2. B

   2 and 3

   2 and 3. Cyanobacteria and diatoms photosynthesise. Foraminifera and copepods graze or heterotroph.

3. C

   3 and 4

   3 and 4. Forams are not the ocean’s primary producers as a class.

4. D

   1 and 4

   1 and 4. Both are mainly consumers.

Summary. Official key is (b) 2 and 3. Ocean primary production is phytoplankton: cyanobacteria and diatoms. Copepods are zooplankton; foraminifera are mostly heterotrophic protists.