NCERT Solutions for Class 8 Science Chapter 10
Important NCERT Questions
8th Chapter 10 Reaching the Age of Adolescence
NCERT Books for Session 2022-2023
CBSE Board and State Board
Questions No: 8 Part: c
Write notes on: Sex determination in the unborn baby.
Share
Sex determination in an unborn baby occurs at conception. Humans possess 23 pairs of chromosomes in most cells, including one pair called sex chromosomes. Females typically have two X chromosomes (XX), while males have one X and one Y chromosome (XY).
At fertilization, if a sperm carrying an X chromosome fertilizes the egg, the combination (XX) results in a female baby. However, if a sperm carrying a Y chromosome fertilizes the egg, the combination (XY) leads to the development of a male baby. The sex of the unborn baby is determined by the combination of chromosomes inherited from the parents during conception, dictating the baby’s development as male or female.
Sex determination in the unborn baby: All human beings have 23 pairs of chromosomes in the nuclei of their cells. Out of these two chromosomes are the sex chromosomes, named X and Y. A female has two X chromosomes, while a male has one X and one Y chromosome. The gametes (egg and sperm) have only one set of chromosomes. The unfertilised egg always has one X chromosome but sperms may have X or Y. When a sperm containing X chromosome fertilises the egg, the zygote would have two X chromosomes and develop into a female child. If the sperm contributes a Y chromosome to the egg (ovum) at fertilisation, the zygote would develop into a male child. This concludes that the sex chromosomes of the father determine the sex of an unborn baby.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-10/