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.
- Year 11
- AQA
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.
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.
Equipment
None required.
Content guidance
- Depiction or discussion of sexual content
Supervision
Adult supervision required
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What is the scientific term for differences between members of the same species?
Q2.The genetic material of all organisms is made of a large molecule called .
Q3.Join each term to its correct meaning.
Q4.Genes are sections of DNA that store the genetic code for making __________ .
Q5.Which of these examples of variation is caused by the organism’s genetic material?
Q6.Which of these examples of variation could be passed from a parent to their offspring?
Assessment exit quiz
6 Questions
Q1.Which of these examples of variation is heritable?
Q2.Which of these examples of variation is influenced by the organism’s genetic material and its lifestyle?
Q3.DNA is a polymer made up of ...
Q4.The original DNA sequence has been changed by a , which has created a genetic variant.
