Q158 / 180 · AIIMS 2017 · Zoology

Assertion : XX-XY type of sex determination mechanism is an example of female heterogamety and is found in Drosophila. Reason : Male heterogamety is seen in moths where males produce two different types of gamete.

  • A
    If both assertion and reason are true and reason is the correct explanation of assertion.
  • B
    If both assertion and reason are true but reason is not the correct explanation of assertion.
  • C
    If assertion is true but reason is false.
  • Correct answer
    D
    If both assertion and reason are false.

Solution

Chromosomal determination of sex is based on heterogamety or occurrence of two types of gamete in one of the two sexes. In Drosophila XX-XY type of sex determination is found where males are heterogametic. In moths, ZO-ZZ type of sex determination occur where males are homogametic.

Hence, the correct answer is option: 'D'.

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