1. Which process is represented by given chart? According to that process write down differences between (44, xx) and (44, xy).

   	(22, x)	22, x
   (22, x)	44, xx	(44, xx)
   (22, y)	44, xy	(44, xy)

2. Sex determination process is represented by given chart.
   (44, xx) = Daughter
   (44, xy) = Son
3. A cell of a girl contains only 45, XO chromosomes, which type of chromosome disorder is present in her body? Write any one symptom of it?
4. A cell of a girl contains only 45, XO chromosomes, it is turner's syndrome. Its symptom is female are sterile, poorly developed ovaries, infertility, etc.
5. Write any two differences between Down's syndrome and Turner's syndrome.
6. Any two differences between Down's syndrome and Turner's syndrome is shown below in table:

   Down's Syndrome	Turner's syndrome
   It is caused due to the pressure of one extra chromosome in 21st set of chromosome cell.	It is caused due to the absence of one X-chromosome in the cell.
   It can occur both in male and female.	It occurs only in female.

7. Write any two effects of Down's Syndrome.
8. Any two effects of Down's Syndrome are listed below:
   1. Decreases a person's physical growth.
   2. Mental and psychological growth slows down.
9. A woman has got only four daughters but no a son. Does it mean that the husband does not produce 'Y' chromosome bearing sperm? Explain it.
10. No, that doesn't mean her husband's sperm doesn't have 'Y' chromosomes. In female, there is both 'X' chromosome but there are 'X' and 'Y' chromosome in a male. During fertilization, the 'X' chromosome of a male is more active than the 'Y' chromosome and got fused with the 'X' chromosome of the female in each conception. As a result, the mother gave birth to four daughters but not a son.
11. Offspring obtained from the same parents show some similarities but they are not exactly similar to each other. Why? Write with reason.
12. Offspring get their characteristics half from their mother and a half from their father so they show some similarities. But there occurs variation in every gene that is inherited by the offspring, so they do not look exactly similar to each other.