Which pair of chromosomes is concerned with Down's syndrome
$7^{th}$
$18^{th}$
$21^{st}$
$23^{rd}$
Wilson detected the colour blindness disease in
What will be possible blood group in children from the parents with $B$ and $AB$ blood groups?
Who gave first experimental evidence of the polygenic concept of inheritance
In a gene pool, along with beneficial mutations those mutations also exists which are damaging to an individual. It has been found that these mutations are irreversible because
$I.$ they have survival value
$II.$ they are acquired
$III.$ they are recessive and carried by heterozygous individuals only
$IV.$ they show genetic drift
Choose the incorrect option for given statement