In humans, the sex of a child is determined by the type of sex chromosome carried by which gamete?

1. All eggs carry an X chromosome, so the mother always contributes X. 2. Sperms are of two kinds, X-bearing and Y-bearing, produced in equal numbers. 3. An X-sperm gives XX (female) and a Y-sperm gives XY (male). 4. Since the variable chromosome comes from the sperm, the father determines the sex, option B. 5. The mother contributes only X, so she cannot decide sex, which rules out option A. _Source: Samacheer Kalvi (TN SCERT) Class 10 Science, Unit 18 Genetics "Sex Determination in Human", p.276_