A food chain occurring in the sea which provides food for many people can be written as :
phytoplankton `to` zooplankton `to` X `to` Y
(a) Name one phytoplankton.
(b) Name two zooplanktons.
(c) What could be X ?
(d) Name the organism which Y could be.
(e) Which organism in the above food chain is a (i) primary consumer, and (ii) tertiary consumer ?