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

The following characteristics are most suitable for which of the following processes?
$(i)$ Due to alteration of $DNA$ sequences,the genotype is changed.
$(ii)$ Changes occur in the phenotype.
$(iii)$ Variation is created in $DNA$.

The concept of sudden genetic change which breeds true in a species is represented as

The sixth mutant codon of the beta globin gene causing polymerization of haemoglobin and change in $RBC$ shape is . . . . . . .

$A$ mutation that arises due to a change in a single base pair of $DNA$ is known as .... mutation.

What is the cause of mutation?