How many plant and animal types do exist on earth?

How are plants and animals kept in museums?

How do plants and animnals help each other in the exchange of gases in the atmosphere ?

How human beings depend upon plants and animals for nutrition ?

How many species of plants and animals have been named so far?

How do animals move?

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 as ? How do microbes fulfill their energy requirements?