Section 8 1 Review Chromosomes

What is a chromosome?

Chromosomes are bundles of tightly coiled DNA located within the nucleus of almost every cell in our body. Humans take 23 pairs of chromosomes.

Illustration showing how DNA is packaged into a chromosome.

Analogy showing how DNA is packaged into a chromosome.
Paradigm credit: Genome Inquiry Express

In plant and animate being cells, DNA is tightly packaged into thread-like structures called chromosomes. This is in contrast to bacteria where Dna floats freely effectually the prison cell.
A single length of Deoxyribonucleic acid is wrapped many times around lots of proteins called histones, to form structures called nucleosomes.
These nucleosomes and so gyre up tightly to create chromatin loops.
The chromatin loops are then wrapped around each other to brand a full chromosome.
Each chromosome has two short arms (p arms), two longer artillery (q arms), and a centromere holding it all together at the centre.
Humans have 23 pairs of chromosomes (46 in total): i set comes from your mother and i set comes from your father.
Of these 23 pairs, one pair are sex chromosomes and then differ depending on whether you are male or female (Xx for female or XY for male person).
The other 22 pairs are autosomes (non-sex chromosomes) and await the same for both males and females.
The DNA making upward each of our chromosomes contains thousands of genes.
At the ends of each of our chromosomes are sections of DNA called telomeres. Telomeres protect the ends of the chromosomes during Dna replication by forming a cap, much like the plastic tip on a shoelace.

This page was last updated on 2016-01-25

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Source: https://www.yourgenome.org/facts/what-is-a-chromosome/