Question

If an individual was XXYY, what would be their apparent sex?

Select one: a. Female b. Intersex c. Male

If an individual was XXYY, how many active sex chromosomes would they have?

Select one: a. four b. three c. one d. two

Answer 1

We Know Females have two X chromosomes (XX) and Males have one X and one Y Chromosome (XY). The Appearanceof at least one Y chromosome with properly functioning SRY gene makes a male. Therefore, Humans with XXYY are genotypically Male.

so option 'c' is correct.

The condition 48,XXYY is not inherited; it usually occurs as a random event during the formation of reproductive cells (eggs and sperm). An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. In 48,XXYY syndrome, the extra sex chromosomes almost always come from a sperm cell. Nondisjunction may cause a sperm cell to gain two extra sex chromosomes, resulting in a sperm cell with three sex chromosomes (one X and two Y chromosomes). If that sperm cell fertilizes a normal egg cell with one X chromosome, the resulting child will have two X chromosomes and two Y chromosomes in each of his body's cells.

Thus here all 4 sex chromosomes are active chromosomes but as X is dominant over Y so the Male will have reduced Testosterone and undeveloped Testes.

so option 'a' is correct.