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In Drosophila the XXY condition leads to femaleness whereas in human beings the same condition leads to Klinefelter's syndrome in males. It proves:

Correct answer: A. In human beings Y chromosme is active in sex determination.

  • A. In human beings Y chromosme is active in sex determination.
  • B. Y chromosome is active in sex determination in both human beings and Drosophila.
  • C. In Drosophila Y chromosome decides femaleness.
  • D. Y chromosome of man have genes for syndrome.

Explanation

The different outcomes of the XXY condition in Drosophila and human beings demonstrate that the mechanisms of sex determination are species-specific. In humans, the Y chromosome is active in sex determination and leads to maleness. In Drosophila, the number of X chromosomes primarily determines sex, with two X chromosomes resulting in femaleness and one X chromosome leading to maleness. Therefore, the correct answer is option (a).

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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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