Inheritance of sex

Cards (11)

  • How many pairs of chromosomes do humans have?
    23 pairs
  • What do the 22 pairs of chromosomes determine?
    Inherited characteristics
  • What are the sex chromosomes in males?
    X and Y
  • What are the sex chromosomes in females?
    X and X
  • How do the gametes of a female differ from those of a male regarding sex chromosomes?
    Females have only X chromosomes
  • What is the composition of male gametes regarding sex chromosomes?
    Half X and half Y chromosomes
  • If a couple has offspring, what are the possible combinations of sex chromosomes?
    XX for female, XY for male
  • What is the average ratio of female to male offspring?
    1 to 1
  • Why might a couple have several offspring of the same sex?
    Because of probabilities in inheritance
  • Where can students find questions on the inheritance of sex?
    In the revision workbook
  • What are the key points about sex chromosome inheritance?
    • Males have XY chromosomes
    • Females have XX chromosomes
    • Female gametes contain only X chromosomes
    • Male gametes contain X and Y chromosomes
    • Offspring can be XX (female) or XY (male)
    • Average ratio of female to male is 1:1