Apart from plants and animals, microbes form a permanent biotic component in an ecosystem. While plants have been referred to as autotrophs and animals as heterotrophs, what are microbes referred to as ? How do the microbes fulfil their energy requirements ?

Which one of the following ecosystems is more productive in terms of carbon dioxide fixation

Study of Biogeochemical cycles is called Biogeochemistry. Its father is Vernadsky $(=Winodgsky)$. It involves

If there was no $CO_2$ in the earth's atmosphere, the temperature of earth's surface would be

Biomass pyramid of forest is