Alleles, genotype, and phenotype
I can explain how the genotype affects the phenotype of an organism.
Alleles, genotype, and phenotype
I can explain how the genotype affects the phenotype of an organism.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- An individual inherits two copies of each gene in a pair of chromosomes.
- Versions of genes are called alleles, they can be recessive or dominant, indicated with a capital or lowercase letter.
- The combination of alleles that an organism has is called its genotype.
- Different alleles of a gene are associated with different versions of the same characteristic called the phenotype.
- Some phenotypes are determined only by genotype, others are also affected by the environment.
Keywords
Allele - A genetic variant in a gene creates an allele (a different version of the gene), which produces a different phenotype.
Dominant - One or both dominant alleles in the genotype for the characteristic to be expressed in the phenotype.
Recessive - Two recessive alleles in the genotype for the characteristic to be expressed in the phenotype.
Genotype - The combination of alleles an organism has for a characteristic (i.e. phenotype).
Phenotype - Features that result, at least partly, from the genetic code of an organism’s genes.
Common misconception
A dominant condition is 'stronger' and that only the strongest characteristic is inherited from one parent.
Two genes are inherited, so both alleles contribute to the genotype. In some cases one is dominant and therefore will always be expressed (through protein structure) in the phenotype, the recessive allele is still present.
To help you plan your year 10 combined science lesson on: Alleles, genotype, and phenotype, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 10 combined science lesson on: Alleles, genotype, and phenotype, 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
A genetic variant of a gene coding for a different phenotype.
Only one copy of this type of allele will cause a phenotypic feature.
The combination of alleles an organism has for a feature.
Observable features that are at least partly caused by genes.
Two copies of this allele are needed to cause a phenotypic feature.