What is a chromosome? مفهوم الكروموسوم
Chromosomes are tightly coiled microscopic rod-like structures of DNA and protein that are found in the nuclei of eukaryotic cells.
Each chromosome contains a single molecule of DNA.
Each chromosome contains a single molecule of DNA.
Each strand of the DNA double helix is a linear arrangement of repeating similar units called nucleotides, which are each composed of one sugar, one phosphate, and a nitrogenous base.
A DNA nucleotide contains one of four different nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G).
The order of bases along a strand of DNA is what determines the genome sequence.
See a DNA Structure diagram.
How many chromosomes are in the human genome?
The nucleus of most human cells contains two sets of chromosomes, one set given by each parent. Each set has 23 single chromosomes--22 autosomes and an X or Y sex chromosome.
A normal female will have a pair of X chromosomes; a male will have an X and Y pair.
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