Question

Key factor of sex determination in humans is:

• A. Y chromosome
• B. X chromosome
  
• C. Autosomes
• D. Both A and B

Answer 1

The correct option is A Y chromosome

• The female gamete or egg has only X chromosome as the sex chromosome.
• The male gametes or sperms can have either X or Y chromosome as the sex chromosome.
• Sex in humans is determined by the type of sperm that fuses with the female egg.
• When the sperm with the X chromosome fuses with the egg, then the child will be female (XX).
  
• When the sperm with the Y chromosome fuses with the egg, then the child will be male (XY).
  
• Hence, we can say that the key factor for sex determination in humans is the Y chromosome.

So, the correct answer is option A.