Question

An imaginary pyramid of numbers is given. What can be one of the possibilities about certain organisms at the different trophic levels?

• A. Level PP is phytoplankton in sea and top level TC is whale
• B. Level one PP is peepal tree and level SC is sheep
• C. Level PC is rats and level SC is cats
• D. Level PC is insects and level SC is small insectivorous birds

Answer 1

The correct option is D Level PC is insects and level SC is small insectivorous birds

With respect to the given image, the first option represents an aquatic ecosystem where primary producers are the phytoplankton and tertiary consumers are the whales, this is incorrect because a single phytoplankton cannot sustain this ecosystem. The second option represents forest ecosystem where the primary producer is a tree, which is possible, however the secondary consumers cannot be sheep as sheep are primary consumers. In the third option, primary consumers being rats are unlikely as they are ominivores and do not feed exclusively on plants; further cats are top carnivores, there cannot be a tertiary consumer in this ecosystem. Therefore the fourth option is the correct answer, as it represents insects as the primary consumers, which forms the trophic level with highest number of organisms. They are mostly dependent on one primary producer, like a tree, and secondary consumers are insectivorous birds, which are comparatively lesser in number than the insects which form the previous trophic level.