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

They overwhelmed their visitors in the second half, with Amy Cokayne, Moloney-MacDonald and Jess Breach crossing over before Packer bagged her second of the afternoon.

From BBC • Apr. 25, 2026

Israeli military body Cogat says approximately 1,150 people have left Gaza via the crossing over the past two months and that the same number have entered Gaza.

From BBC • Apr. 7, 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

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

Elisha and his remaining crew had spent eighty-four days crossing over ice, until they found open waters and set sail on the smaller whaling boats.

From "American Spirits" by Barb Rosenstock