Sex Determination Flashcards
All 5 cards in this deck
How many pairs of chromosomes are in an ordinary human body cell, and what do they control?
23 pairs — 22 pairs control characteristics only, and one pair carries the genes that determine sex.
What are the sex chromosomes of a human female and of a human male?
Female = XX, male = XY.
Which parent's gamete determines the sex of a child, and why?
The father's — sperm carry either an X or a Y chromosome, while all egg cells carry an X.
What probability of a male child does a cross between XX and XY predict?
(50%), a 1 : 1 ratio of male to female offspring.
True or false? An ordinary human body cell contains 23 chromosomes.
False. It contains 23 pairs, which is 46 chromosomes; a gamete contains 23.