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

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

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

“In Q3, Carvana once again drove industry-leading growth and profitability while crossing over $20 billion revenue run rate scale for the first time,” said CEO and founder Ernie Garcia.

From Barron's • Oct. 29, 2025

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

I didn’t think too much of it back then, but now I could see how the wooden crossing over the creek might have led to my great-great-grandfather’s undoing.

From "Gone Crazy in Alabama" by Rita Williams-Garcia