Question

How many pairs of chromosomes are found in human beings?

Hint:

Humans have 46 chromosomes arranged into 23 pairs: 22 pairs of autosomes and 1 pair of sex chromosomes (XX or XY).

Answer 1

Human beings have a total of 46 chromosomes, which are divided into 23 pairs. These chromosomes contain the genetic material that determines the characteristics of an individual. The pairs are divided into two categories: autosomes and sex chromosomes.
1. Autosomes:
Out of the 23 pairs, 22 are autosomes. These are the non-sex chromosomes and are numbered from 1 to 22. They carry genes that are responsible for the majority of an individual's traits, such as eye color, height, and blood type. The autosomes are the same in both males and females.
2. Sex Chromosomes:
The remaining pair consists of sex chromosomes, which determine the biological sex of the individual. There are two types of sex chromosomes: X and Y.
- In females, the sex chromosomes are XX.
- In males, the sex chromosomes are XY.
The presence of two X chromosomes (XX) typically results in a female, while one X and one Y chromosome (XY) results in a male. The sex chromosomes not only determine sex but also carry genes that influence sexual development and fertility.
3. Chromosomal Disorders:
The number of chromosomes is usually fixed at 46 (23 pairs). However, in some cases, there can be chromosomal abnormalities, such as Down syndrome, where an individual has 47 chromosomes (an extra copy of chromosome 21). Other disorders like Turner syndrome (45 chromosomes, missing one X in females) and Klinefelter syndrome (47 chromosomes, with an extra X in males) can also occur due to chromosomal abnormalities.
Thus, the total number of pairs of chromosomes in humans is 23.