Homologous chromosomes

Definition

Homologous chromosomes are pairs of chromosomes in a diploid organism that have the same length, gene position, and centromere location. Each pair consists of one chromosome from the mother and one from the father, containing genes for the same traits at corresponding loci.

5 Must Know Facts For Your Next Test

1. Homologous chromosomes undergo synapsis and crossing over during meiosis I.
2. They are crucial for genetic variation because they exchange genetic material during meiosis.
3. Each homologous chromosome pair is similar but not identical due to different alleles.
4. In humans, there are 23 pairs of homologous chromosomes totaling 46 chromosomes.
5. Errors in the separation of homologous chromosomes can lead to genetic disorders such as Down syndrome.

Review Questions

• What is the role of homologous chromosomes in meiosis?
• How do homologous chromosomes contribute to genetic diversity?
• What can result from errors in the separation of homologous chromosomes during cell division?

Related terms

Meiosis: A type of cell division that reduces the chromosome number by half, creating four haploid cells.

Allele: Different forms or variants of a gene found at the same place on a chromosome.

Crossing Over: The exchange of genetic material between homologous chromosomes during meiosis I, leading to new combinations of alleles.