Albinism is known to be due to an autosomal recessive mutation. The first child of a couple with normal skin pigmentation was an albino. What is the probability that their second child will also be an albino?
Correct answer: D. 25%
- A. 50%
- B. 75%
- C. 100%
- D. 25%
Explanation
The probability that the second child of a couple with normal skin pigmentation will also be an albino (aa) is 25%. This probability is derived from the fact that both parents are carriers of the autosomal recessive allele (Aa), and there is a 25% chance that they will pass on the albino allele to their second child, following Mendelian principles of inheritance.
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About Inheritance
Mendel's laws explain segregation, independent assortment and the prediction of genetic ratios using alleles, genotypes and phenotypes. The chapter also covers linked genes, recombination and crossing over during meiosis, then applies pedigree reasoning to X-linked recessive traits, which show different inheritance patterns in males and females.
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