Question

How is the sex of a newborn determined in humans?

• A. The sex of the individual is genetically determined.
• B. The sex of the individual is phenotypically determined.
• C. The sex of the individual is physiologically determined.
• D. None of the above.

Answer 1

The correct option is A The sex of the individual is genetically determined.

Sex is determined at the time of fertilisation. A human male has XY sex chromosome and produces two types of sperms, either with X chromosome or with a Y chromosome.

A human female has XX chromosome and produces ova of one type. If the sperm containing X chromosome fuses with ovum, the individual will be a girl and the sperm containing Y chromosome fuses with ovum, the individual will be a boy.

Thus, the sex of the individual is genetically determined.