Crossover

Definition

Crossover is the process where homologous chromosomes exchange genetic material during prophase I of meiosis. This results in new combinations of alleles and increases genetic diversity in gametes.

5 Must Know Facts For Your Next Test

1. Crossover occurs during prophase I of meiosis.
2. It involves the exchange of genetic material between non-sister chromatids of homologous chromosomes.
3. The points where crossover occurs are called chiasmata.
4. Crossover contributes to genetic variation in sexually reproducing organisms.
5. Errors in crossover can lead to chromosomal abnormalities such as deletions or duplications.

Review Questions

• During which phase of meiosis does crossover occur?
• What are the structures involved in the process of crossing over?
• How does crossover contribute to genetic diversity?

Related terms

Homologous Chromosomes: Chromosome pairs, one from each parent, that are similar in shape, size, and genetic content.

Chiasmata: The points where two homologous non-sister chromatids exchange genetic material during crossover.

Genetic Variation: Differences in DNA sequences among individuals within a population, often resulting from processes like mutation, recombination (including crossover), and independent assortment.