inheritance of sex

• How many pairs of chromosomes do humans contain?

  23 pairs
• What do 22 of the chromosome pairs determine?

  Inherited characteristics
• What are the sex chromosomes in males?

  X Y
• What are the sex chromosomes in females?

  X X
• What is the significance of the sex chromosomes being different in males?

  It indicates male genetic contribution
• What do all of the woman's gametes contain?

  X chromosome
• What do half of the man's gametes contain?

  X and Y chromosomes
• If a couple has offspring, what are the possible combinations of sex chromosomes?

  XX or XY
• What is the expected ratio of female to male offspring?

  1 to 1
• Why might a couple have several offspring of the same sex?

  Due to probabilities in sex inheritance