Name the scientist who proposed the Mutation Theory.

$A$: Sickle cell anaemia occurs due to a point mutation.
$R$: $mRNA$ produced from the $Hb^S$ gene has $GUG$ instead of $GAG$.

$X$-rays typically induce . . . . . . .

What does a point mutation involve?

$A$ mutation in a single base pair of a gene results in the production of a non-functional protein. This type of mutation is called .............

Which of the following is the most effective chemical mutagen that induces mutations?