Homologous Chromosomes Definition
Chromosomes are the genetic information coded into human DNA. Each person has 23 pairs of chromosomes, or 46 chromosomes in total. Homologous chromosomes are essentially similar in size, and carry the same genetic information.
Examples of Homologous Chromosomes
Homologous chromosomes primarily occur in two scenarios:
- Cell division
A Divisive Matter
Homologous chromosomes exist in one person during mitosis, or cell division. When in mitosis, cells replicate themselves – DNA included – to regenerate human tissue. Although these copies of DNA are identical, the chromosomes they carry are about the same size and have the same genetic information as their predecessors. Therefore, technically speaking, the chromosomes produced during mitosis are homologous to an extreme level.
Females and Males
Single-chromosome gametes, or sex cells, are more common examples of homologous chromosomes in action. When the body undergoes meiosis, or the creation of sex cells, chromosomes do not divide from replicated pairs. Instead, the original chromosome pair and its copy split in two. What results are four, single-chromosome gametes. They are stored in male sperm and the female egg, respectively.
When a female becomes pregnant, she combines one of her eggs with a male sperm. On a genetic level, her 22-chromosome set combines with her male partner’s 22-chromosome set. Since each chromosome from the female’s 22-chromosome set is similar in size to, and carries similar genetic information as, the male’s 22-chromosome set, they are homologous.
Related Biology Terms
- Mitosis – Cell division where DNA is replicated, and one new cell divides from the original.
- Meiosis – Cell division where DNA is replicated, and individual chromosomes do not form pairs. Four new cells divide from the original, each containing only one set of genetic information.
- Gamete – A male or female reproductive cell that contains only one set of human genetic information.
2. When a female becomes pregnant, the homologous chromosomes necessary for fetal formation are located in these.
3. Homologous chromosomes are about the same ______ and carry similar ________.
A. age, credit scores
B. width, DNA
C. beast, fake IDs
D. size, genetic information