Asked in Premeth Test 27 — InheritanceModerate

Lack of independent assortment of two genes A and B in fruit fly Drosophila is due to:

Correct answer: C. Linkage

  • A. Repulsion
  • B. Recombination
  • C. Linkage
  • D. Crossing over

Explanation

The correct answer is linkage. Genetic linkage occurs when genes are located close together on the same chromosome, leading to their co-inheritance more frequently than expected under independent assortment. This proximity reduces the chance of recombination occurring between them during meiosis. While recombination and crossing over can alter allele combinations, they do not cause the lack of independent assortment. Repulsion refers to the arrangement of alleles on homologous chromosomes and is not related to linkage.

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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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