Which of the following has the largest population in a food chain?

Which of the following is the correct sequence in a food chain?

The reservoir pool of carbon is

Identify the group of herbivores from the following that are included as primary consumers in an ecosystem.

Identify the likely organisms $(1), (2), (3)$ and $(4)$ in the food web shown below.

Identify the correct statements from the following:
$(1)$ Succession occurring in dry areas is called xerarch succession.
$(2)$ The stage where plants can survive in open conditions throughout the year is the herb stage.
$(3)$ Ecological succession leads to a decrease in the net primary productivity of the community.
$(4)$ Primary succession takes an average of $1000$ years to complete.