Which of the following are called key industry animals?

Why are relationships such as food chains,food webs,and nutrient cycles important in an ecosystem?

Which of the following would appear as the pioneer organisms on bare rocks?

In a pond,we see plants which are free-floating; rooted-submerged; rooted-emergent; and rooted with floating leaves. Identify the type of plant for each of the following:

Plant Name	Type
$(1)$ Hydrilla	....................
$(2)$ Typha	....................
$(3)$ Nymphaea	....................
$(4)$ Lemna	....................
$(5)$ Vallisneria	....................

Give any two examples of xerarch succession.

Which one of the following systems constitutes the primary producers?