Question

Q9 a) Explain why a food chain usually cannot have more than three or four steps.
b) Calculate the amount of energy that will be available to big fish in the following food chain , if 10,1000J of energy is available to small algae from the sun
Small algae ------Zooplankton------fish-----big fish

Answer 1

a) see the figure bcz plant trap light they are primary producers then primary consumers like grazing animals then secondary carnivores
are secondary consumers like man or bear then tertiary consumers like lion

you are not going to eat lion

b) follow 10% rule
small algae: 101000
zooplankton: 10100
fish: 1010
big fish: 101