crossing over

American  

noun

Genetics.

1. the interchange of corresponding chromatid segments of homologous chromosomes with their linked genes.

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crossing over British  

noun

1. biology the interchange of sections between pairing homologous chromosomes during the diplotene stage of meiosis. It results in the rearrangement of genes and produces variation in the inherited characteristics of the offspring See also linkage

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crossing over Scientific  

/ krô′sĭng-ō′vər /

1. The exchange of genetic material between homologous chromosomes that occurs during meiosis and contributes to genetic variability.

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Etymology

Origin of crossing over

First recorded in 1910–15

Example Sentences

He said the flight took a route down along Saudi Arabia, before "crossing over Israel".

From BBC • Mar. 6, 2026

Once hunted to extinction in France, wolves began crossing over from Italy after gaining protected status under the 1979 Bern Convention.

From Barron's • Feb. 16, 2026

Gold traded up 0.8% Friday, and is less than $50 away from crossing over the $5,000-per-ounce threshold for the first time.

From The Wall Street Journal • Jan. 23, 2026

Next came an overnight bus ride to their final destination: tiny Swink, Colo., where Japanese American farmers had previously employed Alvarado’s wealthier uncles, writing a letter of recommendation this time to make crossing over easier.

From Los Angeles Times • Oct. 10, 2025

She clicked her tongue and he sped into a trot, crossing over the little bridge near the house, heading south to the archery grounds.

From Anya and the Nightingale by Sofiya Pasternack