Question

How many autosomes do human cells contain?

Answer 1

Autosomes are the chromosomes other than the sex chromosomes that are present inside the nucleus of all cells of a human body.

Complete answer:
Chromosomes are thread-like structures made up of DNA and proteins that are present inside the nucleus of a cell and carry genetic information from one generation to another.

They also play an important role in heredity and variation, mutation, cell division, etc. Humans are diploid organisms that have 46 chromosomes. These chromosomes are paired into 23 pairs of homologous chromosomes that are identical to each other in shape and size and are called homologues of each other. These homologous chromosomes have the same pattern of light and dark bands. The human gametes are haploid and contain only 23 chromosomes. During sexual reproduction, the male and female gametes combine to form the diploid zygote. Thus, in a pair of a homologous chromosome, one copy comes from the paternal side and the other from the maternal side.

Among these 23 pairs of chromosomes, 22 pairs of chromosomes are autosomes and are responsible for the inheritance of all characteristics except the sex-linked. These 22 pairs of chromosomes are identical to their homologous part and are roughly numbered based on their size. The largest pair of the chromosome forms the first pair, while the smallest forms the 22nd pair. These autosomes are responsible for determining all the traits of an organism. They help the DNA fit into a cell. A large number of protein-coding genes are found on the autosomes that help in the functioning of various organs in our body.
Autosomal disorders occur when there is any mutation in any chromosome of the autosomes. These mutations can be deletion, duplication, insertion, addition, etc. Autosomal disorders can be dominant or recessive.

Examples of a few autosomal disorders are - Cystic fibrosis, sickle cell anemia, Huntington disease, etc.
The last pair of these 23 chromosomes is the allosomes or sex chromosomes that provide sex-linked characteristics and are responsible for the biological sex of an individual. X and Y are the two sex chromosomes. XX pair is found in the females, while XY is found in the males.

Note: There are various autosomal disorders where mutations occur in the autosomes that lead to a change in their numbers. Example of such disorders are-
1.Down Syndrome- The patients have an extra copy of the 21st chromosome.
2.Edward’s Syndrome- The patients have an extra copy of the 18th chromosome.
3.Patau’s Syndrome- The patients have an extra copy of the 13th chromosome.