Write notes on :
Sex determination in the unborn baby.
The sex of the unborn baby is determined by the sex chromosomes of the father. An egg has two X chromosome while a sperm has a X and a Y chromosome. An egg will always have an X chromosome. Therefore, if the sperm contributes X chromosome then the baby will be a female (XX) and if the sperm contributes the Y chromosome, the baby will be a male (XY). So it is the father, who is responsible for the sex of the baby.
Word game : Use the clues to work out the words.
Across
3. Protruding voice box in boys
4. Glands without ducts
7. Endocrine gland attached to brain
8. Secretion of endocrine glands
9. Pancreatic hormone
10. Female hormone
Down
1. Male hormone
2. Secretes thyroxine
3. Another term for Teenage
5. Hormone reaches here through blood stream
6. Voice box
7. Term for changes at adolescence.
The table below shows the data on likely heights of boys and girls as they grow in age. Draw graphs height and age for both boys and girls on the same graph paper. What conclusions can be drawn from these graphs?
|
Age Year |
Height (cm) |
|
|
Boys |
Girls |
|
|
0 4 8 12 16 20 |
53 96 114 129 150 173 |
53 92 110 133 150 165 |
Write notes on :
Secondary sexual characters.
