A gene showing codominance has
alleles that are recessive to each other
both alleles independently expressed in the heterozygote
one allele dominant on the other
alleles tightly linked on the same chromosome.
In the $ABO$ system, of blood group which of the following is example of co-dominance ?
Mother and father both have blood group $‘A’$. They have two children one with blood group $‘O’$ and second one with blood group $‘A’$. They have
In a marriage between male with blood group $A$ and female with blood group $B$, the progeny had either blood group $AB$ or $B$. What could be the possible genotype of parents ?
If a human mother has ‘$O$' blood group, the foetus would die if the blood of foetus is
$ABO$ blood grouping is controlled by gene I which has three alleles and show codominance. There are six genotypes. How many phenotypes in all are possible?