$A.$ Variation at genetic level arises due to mutations.
$B.$ Technique of $DNA$ fingerprinting was initially developed by Alec Jeffreys
| Column $– I$ | Column $– II$ |
| $(A)\; AUG$ | $(1)$ Phenyl alanine |
| $(B) \;UAA$ | $(2)$ Methionine |
| $(C)\;UUU$ | $(3)$ Tryptophan |
| $(D) \;UGG$ | $(4)$ Stop |