Which of the following is source of energy to an ecosystem

Driving force of an ecosystem is

What will happen to an ecosystem if :

$(a)$ All producers are removed;

$(b)$ All organisms of herbivore level are eliminated; and

$(c)$ All top carnivore population is removed

Source of energy in an ecosystem is

The food chain in which microbes split energy rich compounds of the producer community is

Assertion : A network of food chains existing together in an ecosystem is known as food web.
Reason : An animal like kite cannot be a part of a food web.