Inheritance - Mitosis and Meiosis

Chromosomes are thread-like structures of $DNA$, carrying genetic information in the form of genes. In a typical human somatic cell, there are $46$ chromosomes arranged in $23$ pairs ($2n = 46$).

Mitosis is nuclear division giving rise to genetically identical cells. This process is essential for growth, repair of damaged tissues, replacement of cells, and asexual reproduction.

During mitosis, the exact duplication of chromosomes occurs before division, ensuring that each daughter cell receives a full diploid set ($2n$).

Meiosis is a reduction division in which the chromosome number is halved from diploid to haploid ($2n \rightarrow n$), resulting in genetically different cells.

Meiosis is involved in the production of gametes (sperm and egg cells). It increases genetic variation through independent assortment and crossing over.

A diploid cell ($2n$) has two complete sets of chromosomes, while a haploid cell ($n$) has only one set (found in gametes).

Sexual reproduction involves the fusion of two haploid gametes to form a diploid zygote: $n + n = 2n$.