# Independent assortment

> Independent assortment is Mendel's rule that alleles of genes on different chromosomes are passed to gametes independently of each other, creating new trait combinations.

- Canonical: https://genetixbay.com/knowledge/glossary/independent-assortment.html
- Also written: law of independent assortment, Mendel's second law, free assortment
- Glossary category: Genetics and breeding · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

Independent assortment is Mendel's second law: [genes](https://genetixbay.com/knowledge/glossary/gene.md) on different [chromosomes](https://genetixbay.com/knowledge/glossary/chromosome.md) (or far apart on one) are inherited independently. Which [allele](https://genetixbay.com/knowledge/glossary/allele.md) a gamete gets at one gene tells you nothing about which allele it gets at another. That is how a cross produces combinations neither parent had.

## In practice

It is the reason breeders can combine traits. Cross a plant with dense resin but late flowering to an early plant with thin resin; if the genes involved are on different chromosomes, some [F2](https://genetixbay.com/knowledge/glossary/f2.md) plants will be early and resinous. The expected two-gene F2 ratio is 9:3:3:1, so the wanted double combination may be only 1 in 16, or rarer if both traits are [recessive](https://genetixbay.com/knowledge/glossary/recessive.md).

Cannabis has 10 chromosome pairs, so many genes do assort independently. Genes close together on one chromosome do not: they tend to travel together, which is [linkage](https://genetixbay.com/knowledge/glossary/linkage.md).

## Don't confuse with

- **Segregation**: separation of two alleles of one gene; assortment is about how different genes combine.
- **Linkage**: the exception, when genes sit near each other and are inherited as a block.
- **Recombination**: crossing over within a chromosome, which is what eventually breaks linkage.

## Related terms

[Segregation](https://genetixbay.com/knowledge/glossary/segregation.md), [Linkage](https://genetixbay.com/knowledge/glossary/linkage.md), [Mendelian inheritance](https://genetixbay.com/knowledge/glossary/mendelian-inheritance.md), [Punnett square](https://genetixbay.com/knowledge/glossary/punnett-square.md), [Chromosome](https://genetixbay.com/knowledge/glossary/chromosome.md)

## Read more

- [Mendelian genetics for growers, with Punnett squares](https://genetixbay.com/knowledge/breeding/mendelian-genetics-for-growers.md)

## Sources

1. Miko I. 2008. Gregor Mendel and the principles of inheritance. Nature Education 1(1):134. https://www.nature.com/scitable/topicpage/gregor-mendel-and-the-principles-of-inheritance-593/