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

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

The band was a key part of a phenomenon known as Hallyu, which describes South Korean pop culture crossing over to the west.

From BBC • Jan. 13, 2026

Illia Issaiev hated it when his family fled the fighting by crossing over into Russia.

From Barron's • Dec. 17, 2025

We finally parked underneath the Little Village Arch, a colonial-style gateway crossing over the part of 26th Street where Uber dropped me off earlier.

From Los Angeles Times • Nov. 9, 2025

She and a group of friends had gone backcountry mountain climbing and skiing, crossing over glaciers and racing down snowy peaks hundreds of miles away from Mount St. Helens.

From "Mountain of Fire" by Rebecca E. F. Barone