Sex Determination
Biology: AQA GCSE Higher, topic 6.1.26
Sex Determination
Healthy human body cells contain 23 pairs of chromosomes, only one of which is responsible for determining biological sex. This pair of chromosomes are called the sex chromosomes and can either be X or Y:
Females
Female biology is XX, so an egg contains one X chromosome.
Males
Males biology is XY, so a sperm contains either one X or one Y chromosome.
Test yourself on Sex Determination
What sex chromosome combination will an offspring have if a sperm carrying a Y chromosome fertilises an egg?
Why does the father's sperm determine the biological sex of the offspring, rather than the mother's egg?
What sex chromosome can a sperm cell carry?
Why will every human offspring inherit at least one X chromosome?