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NEETZoologyPrinciples of Inheritance and Variation

What is the XO type of sex determination?

Options

  1. ABoth sexes have an equal number of X-chromosomes
  2. BAll eggs have an additional X-chromosome, and some sperms have X-chromosomes
  3. CMales have two X-chromosomes, and females have one
  4. DFemales have one X-chromosome, and males have none

Correct answer

B. All eggs have an additional X-chromosome, and some sperms have X-chromosomes

Step-by-step solution

It was also observed that in a large number of insects the mechanism of sex determination is of the XO type, i.e., all eggs bear an additional X-chromosome besides the other chromosomes (autosomes). On the other hand, some of the sperms bear the X-chromosome whereas some do not. Eggs fertilized by sperm having an X-chromosome become females and those fertilized by sperm that do not have an X-chromosome become males. Do you think the number of chromosomes in the male and female are equal? Due to the involvement of t

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