Homologous Chromosomes

Cell Biology, Genetics, Human Biology

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:

Example #1: 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.

Example #2: 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.

Homologous chromosomes

Homologous chromosomes

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.

Quiz

1. This process allows for homologous chromosomes to come into contact without sexual intercourse.
A. Meandering
B. Cell division
C. Cell divisiveness
D. Cell direction

Answer to Question #1

2. When a female becomes pregnant, the homologous chromosomes necessary for fetal formation are located in these.
A. Grametes
B. Gromits
C. Gametes
D. Gamers

Answer to Question #2

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

Answer to Question #3
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