How does the gene

• The plasma membrane of RBCs contain many antigens based on the presence or absence of various antigens, blood is categorized into different blood groups.

• The ABO blood group (A,B,AB and O) is based on presence of ABO antigens. The ABO antigens are complex oligosaccharides present in form of glycoproteins and glycolipids.

• There are three alleles that is I^A, I^B and i.

I^A and I^B dominant over i and I^A, I^B can co-dominant each other then the blood group will be AB.

• These alleles helps to determine the blood group of a person as shown in table below-

OR

1) Female XX with male XO:

Crickets, grasshopper and some insects in which female is homogametic and male is hetrogemetic but has only one sex chromosome produce gametes with (X) or without (O) a sex chromosome.

2) Female ZW with male ZZ :

In some birds, butterflies, moths etc females are hetrogemetic produce gametes (Z) and (W), while the male is homogametic produce only (Z) types of sex gametes.