rakukromosoomide

Rakukromosoomid, also known as chromosomes, are thread-like structures found within the nucleus of eukaryotic cells. They are composed of DNA tightly coiled around proteins called histones. This coiling allows the vast amount of genetic material in a cell to fit into a small space. Chromosomes carry the genetic information that determines an organism's traits.

In humans, somatic cells contain 23 pairs of chromosomes, for a total of 46. These include 22 pairs of autosomes and one pair of sex chromosomes (XX for females and XY for males). Gametes, such as sperm and egg cells, are haploid and contain only one set of 23 chromosomes. The number and structure of chromosomes are critical for normal cell function and inheritance.

The structure of a chromosome can be visualized during cell division. Before a cell divides, its DNA replicates, resulting in each chromosome consisting of two identical sister chromatids joined at a centromere. This characteristic X-shape is often depicted when discussing chromosomes. Abnormalities in chromosome number or structure, known as chromosomal aberrations, can lead to various genetic disorders and developmental issues. The study of chromosomes and their behavior is called cytogenetics.