The primary succession in a sere is

$A$ food web:

$A$ bear that eats a fish that further ate bugs that ate algae is a

The maximum evolution of oxygen is by which of the following producers of organic matter?

Fill in the blanks.
$(a)$ Plants are called as . . . . . . because they fix carbon dioxide.
$(b)$ In an ecosystem dominated by trees,the pyramid (of numbers) is . . . . . . type.
$(c)$ In aquatic ecosystems,the limiting factor for the productivity is . . . . . . .
$(d)$ Common detritivores in our ecosystem are . . . . . . .
$(e)$ The major reservoir of carbon on earth is . . . . . . .

Find out the correct order of succession levels in xerarch.