BRAINCAKESampling Errors
Genetic crosses predict expected ratios, such as 3 : 1 or 1 : 1. In real breeding experiments, the observed numbers almost never match these exactly. The main reason is chance.
Each fertilisation is a random, independent event. Which gamete fuses with which is down to chance, so a 3 : 1 ratio is really a probability of 0.75 and 0.25 for each individual offspring, not a guarantee. This difference between the observed and expected results caused by chance is called sampling error.
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More in Genetic Information
- Alleles
- Polygenic Traits
- Monohybrid Crosses
- Test Cross
- Mendel
- Law of Segregation
- Law of Independent Assortment
- Multiple Alleles
All 30 lessons in Genetic Information · All Edexcel A-level Biology topics