Homologous chromosome

A pair of chromosomes in a diploid cell which have the same structure as each other are said to be homologous. They contain the same genes at the same loci (e.g. both have eye colour gene) but may contain different alleles (e.g. one may code for brown eyes, one may code for blue), besides being of the same length. They can only be found in diploid cells, such as humans, or polyploid beings. Each homologous chromosome is inherited from a different parent (i.e., one from the mother and one from the father), for example the 46 human chromosomes are in fact 23 homologous pairs of chromosomes, 23 inherited from the mother and 23 from the father (see karyotype for a picture of the 23 pairs of chromosomes). It contains information about the same gene sequence. Homologous chromosomes are all similar in length, except for sex chromosomes in several taxa, where the X chromosome is longer than the Y chromosome; this is because these chromosomes only share a small region of homology.

Not to be confused with sister chromatids.

Homologe kromosomer כרומוזום הומולוגי