Same chapter3 marksDifficulty: Medium
Explain a test cross and state what it is used for.
Principles of Inheritance and Variation
3 marksDifficulty: Medium
A colour-blind man marries a woman with no history of colour blindness in her family. State the condition of their sons and daughters.
Original Khojo Papers practice question — not from a past board paper.
Answer
All the sons will have normal vision and all the daughters will be carriers.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
Colour blindness is X-linked recessive. The father gives his X, which carries the allele, to every daughter, who is therefore a carrier, and his Y to every son, who is therefore unaffected.
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