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

$A$ change in the chromosome number is called

What is the effect of deletion or rearrangement in a segment of $DNA$ on a gene?

The defect sickle-cell anaemia is caused by the . . . . . . of glutamic acid by valine at the $6^{th}$ position of the . . . . . . globin chain of the haemoglobin molecule.

Which of the following discoveries resulted in a Nobel Prize?

The classical example of point mutation is