Grade 12 Biology: Sex-Linked Pedigrees
This worksheet focuses on understanding and analyzing sex-linked inheritance patterns through pedigree charts.
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Grade 12 Biology: Sex-Linked Pedigrees
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Carefully read each question and analyze the provided pedigree charts to answer accurately. Remember to consider the principles of sex-linked inheritance.
1. Briefly explain why sex-linked recessive traits are observed more frequently in males than in females.
2. Examine the pedigree chart below, which represents the inheritance of hemophilia, a sex-linked recessive disorder. Affected individuals are shaded.

a) What is the genotype of individual II-2 (the mother in the second generation)?
b) What is the probability that individual III-1 (the son in the third generation) is affected with hemophilia?
3. In X-linked dominant inheritance, an affected father will pass the trait to all of his daughters.
True
False
4. Y-linked traits are passed from father to all sons.
True
False
5. In X-linked recessive inheritance, a carrier female has a % chance of passing the allele to each of her sons.
6. For a male to express an X-linked recessive trait, he needs only copy of the recessive allele.
7. Which of the following is a characteristic of X-linked recessive inheritance?
Affected fathers pass the trait to all their daughters.
Affected mothers pass the trait to all their sons.
Affected mothers pass the trait to all their daughters.
Affected sons inherit the trait from their mothers.