Home › UP Board Class 12 › biology › Principles of Inheritance and Variation › The sex of a human baby is determined by:
The sex of a human baby is determined by:
AThe mother's egg cell which has different types
BHormones during prenatal development phase
CThe X or Y chromosome contributed by the father
DRandom environmental factors during gestation
Answer & Solution
Correct answer: C. The X or Y chromosome contributed by the father
Father is XY: he contributes either X (→ XX daughter) or Y (→ XY son). Mother always contributes X. So father determines the baby's sex.
Related questions
Haemophilia and colour blindness are MORE COMMON in MALES than females because they are:Down syndrome is most commonly caused by:Sickle cell anaemia is caused by:In the human ABO blood group system, a person with blood group AB has the genotype:In snapdragon (Antirrhinum), RR (red) × rr (white) gives F1 plants that are PINK. This patIn a DIHYBRID cross of YyRr × YyRr, the F2 phenotypic ratio is:In a monohybrid cross of Tt × Tt, the F2 PHENOTYPIC ratio is:Mendel conducted his classic genetics experiments using: