Variation and genetic mutations
I can describe how mutations change the DNA sequence in the genome causing genetic variation, which can cause heritable variation in phenotype.
Variation and genetic mutations
I can describe how mutations change the DNA sequence in the genome causing genetic variation, which can cause heritable variation in phenotype.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- Some variation in phenotype is caused only by the environment and is not heritable.
- Some variation is caused by genetic material; this can be passed on to offspring via gametes or asexual reproduction.
- A change in the sequence of bases in an organism's DNA is called a mutation and creates a genetic variant.
- Mutations happen at random (caused by carcinogens, or by ionising radiation, or by errors when DNA is copied).
- Most mutations have no effect on phenotype, some influence phenotype, and a few determine phenotype.
Keywords
Phenotype - The observable traits of an organism.
Variation - Differences between members of the same species.
DNA - A large chemical molecule made of nucleotides. It carries the genetic code of all living organisms.
Mutation - A change in the nucleotide base sequence in the DNA of the genome.
Genetic variant - A region of DNA in which the sequence of nucleotide bases has been changed.
Common misconception
Students have many misconceptions about DNA including, for example, that DNA is alive.
This lesson includes dual coded diagrams of DNA to help avoid embedding misconceptions.
To help you plan your year 11 biology lesson on: Variation and genetic mutations, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 11 biology lesson on: Variation and genetic mutations, 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 biology lessons from the Variation and natural selection at the genetic level unit, dive into the full secondary biology curriculum, or learn more about lesson planning.
Equipment
None required.
Content guidance
- Depiction or discussion of sexual content
Supervision
Adult supervision required
Licence
Starter quiz
6 Questions

all the genetic material of an organism
the combination of alleles an organism has
the visible traits of an organism








Exit quiz
6 Questions













