These belong to the category of primary consumers:

What is an ecosystem service? List any four important ecosystem services provided by the natural ecosystems. Are you in favour or against levying a charge on the service provided by the ecosystem?

What will be the $P/R$ ratio of a climax community and a pioneer community? What explanation could you offer for the changes seen in the $P/R$ ratio of a pioneer community and the climax community?

Which of the following food chains may not be directly dependent upon solar energy?

What does primary succession indicate in the development of a community?

An ecosystem is defined as ...