Science

Reaching the Age of Adolescence

Question:

Write notes on Sex determination in the unborn baby.

Answer:

The sex of a baby is determined by the type of male gamete that fuses with the female gamete. All human beings have 23 pairs of chromosomes in their nuclei. Out of these 23 pairs, the last pair is known as the sex chromosome.The human males have 23 pairs of chromosomes including XY sex chromosomes. Therefore, the male gamete has 22 chromosomes and either an X or Y sex chromosome.Male gametes can be of two types: 22+X or 22+Y Females have 23 pairs of chromosomes including XX sex chromosomes. Therefore, their gametes can only have 22 chromosomes and one X sex chromosome. Type of female gametes: 22+X Thus, as the mother provides only X chromosome, the sex of the baby is determined by the type of male gamete (X or Y)that fuses with the X chromosome of the female.
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Reaching the Age of Adolescence

Q 1.

Define adolescence.

Q 2.

What is menstruation? Explain.

Q 3.

What is the term used for secretions of endocrine glands responsible for changes taking place in the body?

Q 4.

List changes in the body that take place at puberty.

Q 5.

Write notes on Secondary sexual characters.

Q 6.

Write notes on Adam's apple.

Q 7.

What are sex hormones? Why are they named so? State their function.

Q 8.

Write notes on Sex determination in the unborn baby.