What is a homolog?

is a chromosome that shares properties with another chromosome inherited from another parent. During meiosis, when chromosomes pair to duplicate, homologists combine. People have 23 pairs of homologous chromosomes in the body, consisting of 23 chromosomes inherited from each parent.

Chromosomes in the pair are the same lengths and have the same alleles that have a code for different features located in the same positions along their length. However, alleles may vary. For example, one can have one allele for blond hair and one for brown hair. Depending on which is dominant, only one feature will be expressed. Some people inherit two identical alleles, one of each parent, in which case a few homologists will have identical copies. Genetic information about both chromosomes is copied to produce new cells. People who study the number for comfort and when chromosomes are analyzed, one of the first steps is to pair all homologists to confirm that someone has the expected number of chromozOm and looking for any apparent signs of the problem.

Sexual chromosomes are a special exception to the rule that homologists are usually the same length. While X chromosomes found in genetic women are the same size, the Y chromosome is actually shorter than the X chromosome. These two chromosomes create a few homologists where half of the pair of different sizes are. Variations in the structure of X and Y chromosomes are a reflection of human development.

In people with certain genetic disorders, chromosome couples may be disturbed in some way. Chromosomes sometimes have missing information, causing chromosomes outside sex different sizes, some people lack Certain chromosomes completely and other people have too many chromosomes. This can be identified in the karyotype, the image of chromosomes created by dyeing and microscopy.

The term "homolog" is also used in another sense in biology to describe properties transmitsSewn organisms by ordinary ancestors. Many organisms have shared physical properties that reflect their mutual genetic heritage, such as the forelegs seen in mammals from horses to domestic cats. When evolutionary divergence and physical properties develop for new purposes, and in different ways they are said to be analgative.