Codominance is shown by gene controlling

Mendel published his work on inheritance of characters in $1865$ but it remained unrecognised till $1900$ because

$(a)$ He could not provide any physical proof for the existence of factors

$(b)$ His concept of factors as stable, discrete units that controlled the expression of traits did not find acceptance from the contemporaries

$(c)$ Mendel's approach of using mathematics to explain biological phenomena was totally old

$(d)$ Communication was not easy (as it is now)

Coupling and repulsion are the two faces of

Drosophila melanogastor has $8$ chromosomes in somatic cell. How many linkage groups will be there

Which phenomena leads to the variation in $DNA$

Alleles which show independent effect are called