KCET2026BiologyPrinciples of Inheritance and Variation
The genotypes of husband and wife are I^A I^B and I^A I^O . Among the blood groups of their children, how many different genotypes and phenotypes are possible?
Options
- A4 genotypes and 4 phenotypes
- B4 genotypes and 3 phenotypes
- C3 genotypes and 4 phenotypes
- D2 genotypes and 3 phenotypes
Correct answer
B. 4 genotypes and 3 phenotypes
Step-by-step solution
The cross is between the genotypes I^A I^B and I^A I^O . Gametes produced by the husband are I^A and I^B . Gametes produced by the wife are I^A and I^O . The possible genotypes of the offspring are obtained by the combinations of these gametes: I^A I^A (Blood group A) I^A I^O (Blood group A) I^A I^B (Blood group AB) I^B I^O (Blood group B) There are 4 different genotypes: I^A I^A , I^A I^O , I^A I^B , and I^B I^O . There are 3 different phenotypes: Blood group A, Blood group AB, and Blood group B. Thus, 4 genotypes