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What are diploid and haploid cells?

Meaning of Diploid and Haploid Cells

All basic cells, of all living beings, originally have a genome, made up of single or fragmented DNA, responsible for controlling the production of proteins, which act in all cellular processes, directly or indirectly, producing functioning, replication and death. programmed cell phone

In multicellular organisms, which have sexual reproduction, there are cells with a complete set of genes and others with half, they are diploid (2n) and haploid (n) cells, respectively.

Thus, the main distinction between haploid cells and diploid cells is related to the number of chromosomes each cell contains: while diploid cells contain two paired sets of chromosomes (represented by 2n), haploid cells contain one set of chromosomes. (represented by n).

Why do diploid and haploid cells have different numbers of chromosomes?

The difference between the number of sets of chromosomes between these two cells derives from the mechanism of division that originates them and the role they play reproductively and evolutionarily.

Let us see that the haploid cell contains half of the gene set of the species, which allows sexual reproduction, because when one gamete meets the other at fertilization, the originating cell will retrieve the full set of genes.

Consequently, the diploid cell contains one set of chromosomes from the father and one from the mother.

This favors the maintenance of the constant number of chromosomes throughout the generations, even with the exchange of genetic material, and allows to increase the genetic variability of the living beings of the species.

How do haploid and diploid cells form?

Just as there are two types of cells, there are two types of cell division that originate them: mitosis and meiosis.
Mitosis is cell division that gives rise to diploid cells.

It goes through phases in which the DNA is replicated, that is, the genome is duplicated and, when the division occurs, each copy passes to the two newly formed cells, so that nothing varies genetically.

But it is worth remembering that the double set of chromosomes in the genome of cells that divided by mitosis came from fertilization.

In turn, meiosis generates haploid cells. Basically it is a division process that consists of two successive divisions in which the genetic material is duplicated, the pairs of chromosomes are separated and, in the last division, the sister chromatids are separated.

Therefore, four daughter cells originate with half the number of initial chromosomes. It occurs within the male and female gonads, where diploid (2n) germ cells give rise to haploid (n) cells.

Furthermore, meiosis further increases genetic variability because chromosomes that are paired in a cell entering meiosis exchange DNA by recombination, forming new arrangements before splitting into unique sets.

Thus, the haploid gametes formed bring new varieties of genes, and the individual resulting from the fusion of a male and female gamete (zygote) will result in a new unique combination, with unique characteristics, which cannot be repeated.

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