How many of the following statements are incorrect?
(a) The consumers that feed on the herbivores can be called as primary carnivores
(b) The DFC begins with autotrophs
(c) GFC begins with dead organic matter
(d) Green plants occupy the first trophic level in an ecosystem
A food chain is a linear sequence of organisms through which transfer of energy takes place in the form of food as one organism eats another organism.
On the basis of the source of their food, organisms occupy a specific position in the food chain and that is known as their trophic level.
Producers belong to the first trophic level in the ecosystem. They are able to synthesise the food utilising the energy coming from the sun and are hence called autotrophs.
Hence statement d is correct.
The herbivores directly feed on the producers and hence are called primary consumers, they occupy the second trophic level.
The primary carnivores feed on the herbivores and are called secondary consumers and they occupy the third trophic level.
Hence statement a is correct.
The top carnivores (tertiary consumers) belong to the fourth trophic level and they feed on the primary carnivores.
There are two types of food chain: grazing food chain (GFC) and detritus food chain (DFC).
The grazing food chain begins with green plants (autotrophs) which synthesise the food using sunlight and pass on the energy to herbivores and then to carnivores.
Detritus food chain is the type of food chain where energy is gained from the dead organic matter (detritus). DFC begins with dead organic matter, followed by decomposers, detritivores and then their predators.
Hence statements b and c are incorrect.
Therefore, out of the four statements given, two are incorrect.