Starter quiz
- What is the scientific term for differences between members of the same species?
- 'variation' ✓
- The genetic material of all organisms is made of a large molecule called ______.
- 'DNA' ✓
- Join each term to its correct meaning.
- genome⇔all the genetic material of an organism ✓
- genotype⇔the combination of alleles an organism has ✓
- phenotype⇔the visible traits of an organism ✓
- Genes are sections of DNA that store the genetic code for making __________ .
- carbohydrates
- lipids
- nucleotides
- proteins ✓
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- Which of these examples of variation is caused by the organism’s genetic material?
- big muscles
- damage
- dyed hair
- earlobe attachment ✓
- Which of these examples of variation could be passed from a parent to their offspring?
- big muscles
- damage
- dyed hair
- earlobe attachment ✓
Exit quiz
- Which of these examples of variation is heritable?
- blood type ✓
- injury
- natural eye colour ✓
- tattoos
- Which of these examples of variation is influenced by the organism’s genetic material and its lifestyle?
- blood type
- body mass ✓
- scarring
- tattoos
- DNA is a polymer made up of ...
- amino acids.
- bases.
- nucleotides. ✓
- proteins.
-
- The original DNA sequence has been changed by a ______, which has created a genetic variant.
- 'mutation' ✓
- Who is correct?
- Alex: “Mutations are only caused by UV radiation.”
- Izzy: “They can be caused by carcinogens and UV radiation.” ✓
- Jun: “Mutations can be caused by errors when copying DNA.” ✓
- Laura: “It’s just carcinogens that cause mutations in DNA.”
- Put the statements in the correct order to explain how a mutation can affect an organism’s phenotype.
- 1⇔The DNA sequence is changed due to a mutation.
- 2⇔This creates a genetic variant.
- 3⇔The changed sequence codes for a different sequence of amino acids.
- 4⇔A different or a non-functional protein is made.
Worksheet
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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.
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.
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.
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