Moderate

The following results of a cross between two individuals shown in the picture are: Which statement describes the children of the cross?

Correct answer: B. Two child is homozygous recessive, and the other exhibits a dominant phenotype but has a parent with a recessive phenotype.

  • A. One child is homozygous dominant, while the other exhibits a dominant phenotype but has a parent with a recessive phenotype.
  • B. Two child is homozygous recessive, and the other exhibits a dominant phenotype but has a parent with a recessive phenotype.
  • C. One child is homozygous recessive, and the other exhibits a dominant phenotype but has a sibling with a recessive phenotype.
  • D. One child is homozygous recessive, and another exhibits a recessive phenotype, but has a parent with a dominant phenotype.

Explanation

The correct answer is Option B. In a Mendelian cross involving one parent who is homozygous recessive and another who is heterozygous, one offspring can be homozygous recessive, receiving recessive alleles from both parents, resulting in a recessive phenotype. The other offspring can be heterozygous, inheriting a dominant allele from one parent and a recessive allele from the other, which results in a dominant phenotype. Options A and D are incorrect due to incorrect assumptions about the potential genotypes of the offspring. Option C is misleading as it introduces unnecessary sibling relationships that do not contribute to solving the question.

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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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