Genes located on homologous chromosomes for the same trait are called.....

Explain the concept of multiple alleles.

How many of the following genotypes possibly represent normal wings in Drosophila?
$(i)$ $Vg^{+} Vg^{+}$
(ii) $Vg^{+} vg^{ni}$
(iii) $Vg^{+} vg^{no}$
(iv) $Vg^{+} vg^{st}$
$(v)$ $Vg^{+} vg$

In the $ABO$ blood grouping system,what are the number of possible phenotypes and genotypes,respectively?

$A$ male with heterozygous blood group $B$ and a female with homozygous blood group $A$ have offspring. What are the possible genotypes and phenotypes in their progeny?

$ABO$ blood groups are controlled by the gene: