Question

Which of the following species is a primary consumer in the given food web?
A) F
B) G
C) H
D) K

Answer 1

Hint:Trophic levels in ecosystems can be described as food chains, but it is more accurate to call them food webs. This is because interactions can criss-cross and are rarely simply linear relationships.

Complete answer:
The different levels in a food web include the producers, primary consumers, secondary and tertiary consumers, and the decomposers. Secondary and tertiary consumers can have different levels depending on the other organism around them.

The producers are the autotrophs which are essentially the green plants. These include the microscopic algae, phytoplankton, and cyanobacteria, and then go all the way up to the fruit-bearing flowering plants.

Primary consumers are those who feed on the producers/autotrophs. These are the larger herbivorous animals and the tiny organisms that feed on algae. Even among the primary consumers, there is division based on the type of autotrophs they consume. They could be grass eaters, fruitarians, seed eating, phytoplankton consumers, and so on.

In the given food web, F is a producer or autotroph. Option A is incorrect.
G is one level up from F. G is a primary consumer. Option B is the correct answer.
H and K can be secondary, tertiary, or even quaternary consumers depending on which pathway is followed in the given food web. Options C and D are incorrect.

Hence the correct answers option ‘B’.

Note:Primary consumers are of special importance in an ecosystem because they are the intermediate path via which the energy produced by the autotrophs/producers is made available for the secondary and tertiary consumers. Without them the ecosystems would fall apart.