Question

Explain the sex determination in baby.

Answer 1

Hint: A chromosome is a structured package of DNA found in the nucleus of the cell. Diverse organisms have different numbers of chromosomes. Human beings have 23 pairs of chromosomes, 22 pairs of numbered chromosomes which are called autosomes, and one pair of sex chromosomes that are X and Y. Each parent contributes one chromosome to each pair.

Complete Answer:
- The term chromosome is derived from the Greek word ‘color’ that is chroma and body soma. Scientists gave this name to chromosomes because they are cell structures or bodies that are strongly stained by some colorful dyes used in research. Chromosomes are thread-like structures that are found inside the nucleus of animal and plant cells.
- Every chromosome is made up of protein and a single molecule of deoxyribonucleic acid (DNA). DNA contains the specific instructions that make each type of living creature unique which passes from the parents to the offspring.
- Human beings have 46 chromosomes with 23 pairs. Out of these, two chromosomes that are the chromosomes X and Y are the sex chromosomes. A female has two X chromosomes. And a male has one X and one Y chromosome. The female gamete is the ovum and the male gamete is sperm, it holds only one set of chromosomes.
- The unfertilized egg, all the time, has one X chromosome. However, sperms can have two different types of chromosomes. They may have either an X chromosome or a Y chromosome. When a sperm of the X chromosome from the male fertilizes the egg, the zygote would have two X chromosomes and it may result in the formation of a female child.
- In the case of sperm that contains a Y chromosome and fertilizes with the egg, the zygote would develop into a male child. Hence it is apparent that the sex of an unborn baby is determined by the father's sex chromosomes.

Note: The exceptional structure of chromosomes keeps DNA tightly wrapped around histones. Without such a type of packaging, DNA molecules would be too long to fit inside cells.