Question

A food chain occurring in the sea which provides food for many people can be written as: phytoplankton → zooplankton → X → Y

1. Name one phytoplankton. 
2. Name two zooplanktons. 
3. What could be Х? 
4. Name the organism which Y could be. 
5. Which organism in the above food chain is a (i) primary consumer, and (ii) tertiary consumer?

Answer 1

1. Diatoms (or marine algae).
2. Krill and copepods (or protozoa and small crustaceans).
3. Small fish (such as sardines, anchovies, or herring) that feed on zooplankton.
4. Humans (since the chain provides food for many people).
5. 1. Primary consumer: Zooplankton
   2. Tertiary consumer: Human being (Man)