The grafting between two identical twins is known as

Which is the example of supplementary gene

Linked gene are present on

Mental retardation in man, associated with sex chromosomal abnormality is usually due to

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

Genes exhibiting multiple effects are known as