Question

Explain with the help of a flow chart that in human beings father is responsible for the sex (male or female) of the child.

Answer 1

Flow Chart Explaining Father’s Role in Sex Determination:


 

Sex Determination in Humans

Human females have two X chromosomes (XX) and produce eggs that all carry an X chromosome. Human males have one X and one Y chromosome (XY) and produce two types of sperm:

• 50% of sperm carry an X chromosome
• 50% of sperm carry a Y chromosome

During fertilization:

• If an X egg is fertilized by a sperm carrying X, the resulting zygote has the genotype XX and develops into a female child.
• If an X egg is fertilized by a sperm carrying Y, the resulting zygote has the genotype XY and develops into a male child.

Since the mother can only contribute an X chromosome, the type of chromosome (X or Y) carried by the sperm from the father determines the sex of the child. 

Therefore, the father is responsible for determining the sex of the child.

Summary:

• Parental Contribution:
  • Mother (XX) → only X-type eggs
  • Father (XY) → 50% X sperm, 50% Y sperm
• Offspring Sex Determination:
  • X (egg) + X (sperm) → XX → Female
  • X (egg) + Y (sperm) → XY → Male
• Critical Factor: Chromosome carried by the father's sperm