Same chapter3 marksDifficulty: Medium
Name three genetic disorders in human beings and state the cause of each.
Principles of Inheritance and Variation
3 marksDifficulty: Medium
Explain a test cross and state what it is used for.
Original Khojo Papers practice question — not from a past board paper.
Answer
A test cross is a cross between an individual showing the dominant phenotype and a homozygous recessive individual. If all the offspring show the dominant character the parent was homozygous; if about half show the recessive character it was heterozygous. It is used to determine an unknown genotype.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The ratio in the second case is 1 : 1, not 3 : 1.
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