Question

A colour blind girl is rare because she will be born only when

• A. her mother and maternal grand father were colour blind
• B. her father and maternal grand father were colour blind
• C. her mother is colour blind and father has normal vision
• D. parents have normal vision but grand parents were colour blind.

Answer 1

Answer: (B)

A colour blind girl is rare because she will be I born only when her father and maternal grand father j were colour blind. The genotype of the mother was to be either X^CX^C or X^CX and that of father X^CY so that the daughter becomes colour blind.