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

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

Twenty captives were crossing over Israel’s border to jubilant homecomings, but Bipin wasn’t among them.

From The Wall Street Journal • Oct. 15, 2025

The leaves seem to grow out of the dark gold, to be living things, their stems crossing over one another in a delicate knotwork.

From "The Cruel Prince" by Holly Black