The genotypes of a Husband and Wife are IAIB and IAi. Among the blood types of their children, how many different genotypes and phenotypes are possible?
- 4 genotypes ; 3 phenotypes
- 4 genotypes ; 4 phenotypes
- 3 genotypes ; 4 phenotypes
- 3 genotypes ; 3 phenotypes
Answer
(1) 4 genotypes ; 3 phenotypes
Solution
Cross: IAIB IAi
Gametes of husband: IA, IB; gametes of wife: IA, i
⇒ Children: IAIA, IAi, IAIB, IBi 4 genotypes
⇒ IAIA and IAi blood group A; IAIB blood group AB (IA, IB co-dominant); IBi blood group B
∴ 4 genotypes and 3 phenotypes (A, AB, B).
Answer: (1)