Why are igneous rocks are also called mother rocks?

Differentiate between igneous rocks and sedimentary rocks.

Lichens growing on rocks are called

Give examples of (a) igneous and (b) sedimentary rocks. What is the origin of (a) igneous rocks and (b) sedimentary rocks ?

Plants growing on rocks are called as

Sedimentary Rocks

Igneous rocks act as a source of all other types of rocks. Justify.