Question

Human baby will be a male if its 23rd chromosome pair is ____.

• A. XX
• B. XY
• C. X
• D. XXX

Answer 1

The correct option is B XY

Humans contain 22 pairs of autosomes and 1 pair of sex chromosomes. The female gamete or the egg consists of an “X” chromosome. If this is fertilised by a sperm containing “X” chromosome, the baby will have “XX” chromosome and will be a female. But if the egg is fertilised by a sperm containing “Y” chromosome, the baby will have “XY” chromosome and will be a male.