Question

The chief producers in the oceans, which are also known to form diatomaceous earth belong to

• A. Euglenoids
• B. Chrysophytes
• C. Plantae
• D. Dinoflagellates

Answer 1

The correct option is B Chrysophytes

The chief producers in the oceans are the diatoms which belong to Chrysophytes under kingdom Protista. These are considered as producers as most of them are photosynthetic. The body walls of diatoms are embedded with silica, which contribute to the formation of diatomaceous earth. Diatomaceous earth refers to the large amounts of cell wall deposits in their habitat.
Members of kingdom Plantae, which are also photosynthetic, are the chief producers of the terrestrial environment.
Though Euglenoids under kingdom Protista are also photosynthetic, they behave like heterotrophs when deprived of sunlight.
Dinoflagellates, under under kingdom Protista are also photosynthetic but these are not regarded as chief producers. Moreover, their cell walls do not have silica but some stiff cellulose plates. Hence, these do not contribute to the formation of diatomaceous earth.