The human genome consists of all our various genes, which are the hereditary units of our chromosomes. Humans have 23 pairs chromosomes divided into 22 pairs of autosomes and 1 pair of sex chromosomes. Human chromosomes are complex, consisting of various levels of organization, and their expression determine our behavior at the molecular level.
Chromosome: Coiled structure made of DNA and proteins containing sister chromatids that is the form in which the genetic material of a cell goes through cell division.
Chromatid: One of two identical copies of a chromosome.
Centromere: Region where two sister chromatids are joined together.
Nucleosomes: Unit of DNA where a segment of DNA is wrapped around a histone.
Histones: Proteins that associate with DNA.
Telomere: Repeating segments of non-coding DNA at the end of each chromosome.
Karyotype: Characterizes a cell by describing the number of chromosomes and their appearances under a microscope.
Autosome: Any chromosome that is not a sex chromosome.
Sex Chromosome: Either an X or Y chromosome.
Barr Body: An inactivated X chromosome.
Allele: Variant of a specific gene.
Linked Genes: Genes on the same chromosome.
Sex-Linked Gene: Gene on the same sex chromosome.
X-Linked Gene: Genes on the same X chromosome.
Linkage Map: Shows the relative position of genes on a chromosome.
DNA molecules possess different levels of organization. In its most compact form, DNA with its association of protein is referred to as a chromosome.
Every species has a characteristic number of chromosomes. Humans have 23 pairs of chromosomes (for a total of 46).
A karyotype shows a picture of a human cell’s chromosomes
Humans have around 20,000 to 22,000 genes