The first definite proof of the mutagenic action of $X$-rays was given by

$A$ mutant microorganism is unable to synthesize a component required for its growth,but it is able to grow if that component is provided. This is called a/an......

The short-legged breed of sheep,known as the Ancon sheep,is an example of which of the following?

Most natural mutations are ..........

Write a short note on Mutation.

Mutations are responsible for