Question

When a human egg is fertilized by a sperm having ‘Y’ chromosome, the zygote has the following combination of chromosomes:

• A. 44 + XX
• B. 22 + XX
• C. 44 + XY
• D. 22 + XY

Hint:

Egg always gives X. X sperm → XX (Female), Y sperm → XY (Male).

Answer 1

The Correct Option is C

Concept: Human body cells contain 46 chromosomes:

• 44 autosomes
• 2 sex chromosomes (XX or XY)

Explanation:

• The egg always carries 22 autosomes + X chromosome.
• A sperm can carry either:
  • 22 + X → Female child (XX)
  • 22 + Y → Male child (XY)
• If fertilization occurs with a Y-bearing sperm: \[ (22 + X) + (22 + Y) = 44 + XY \]

Conclusion: If a sperm carrying a Y chromosome fertilizes the egg, the zygote will have 44 autosomes and XY sex chromosomes, resulting in a male child.