Models of single-gene inheritance: Punnett squares
I can interpret and construct Punnet squares to show the inheritance of alleles of a single gene.
Models of single-gene inheritance: Punnett squares
I can interpret and construct Punnet squares to show the inheritance of alleles of a single gene.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- Most characteristics are influenced by multiple genes, but some are determined by just one.
- An individual will inherit two alleles for each gene, the alleles for a gene may be dominant or recessive.
- A Punnett square models inheritance of alleles showing possible genotypes of offspring as homozygous or heterozygous.
- Punnett squares are used to predict proportion of genotypes/phenotypes, or probability of occurrence in the offspring.
- Each instance of sexual reproduction is independent, so does not affect the probability for subsequent offspring.
Keywords
Punnett square - A model used to show the inheritance of alleles from parents to offspring.
Gamete - A sex cell (i.e. sperm and egg) that carries half the genetic information required for an individual organism.
Genotype - The combination of alleles that an individual has for each gene.
Ratio - Shows hows how much of one value there is compared to another.
Probability - A measure of the chance or likelihood of an event occurring.
Common misconception
A gamete has two alleles, Punnett square has too many alleles for gametes. Also that only four offspring are produced and therefore each will definitely have the genotype and phenotype shown.
Model the alleles within gametes so it is clear. Refer to half the gametes having each version, moving away from the idea of divisions of 4.
To help you plan your year 10 combined science lesson on: Models of single-gene inheritance: Punnett squares, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 10 combined science lesson on: Models of single-gene inheritance: Punnett squares, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
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The assessment exit quiz will test your pupils' understanding of the key learning points.
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Explore more key stage 4 combined science lessons from the Inheritance, genotype and phenotype unit, dive into the full secondary combined science curriculum, or learn more about lesson planning.
Licence
Lesson video
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Starter quiz
6 Questions
Exit quiz
6 Questions
has two different alleles for a gene
has two identical alleles for a gene
a measure of the chance of an event happening
shows how much of one value there is compared to another
