1. Mutations: Causes and Effects

2. What Are Mutations?
Sometimes cells make mistakes when copying their own DNA
Def: Mutations are changes in the genetic material
The chances of a mutation occurring can be increased by chemical or physical factors

3. What Are Mutations? Gene mutations
These mutations involve a change in one or a few nucleotides and affect a single gene

4. WHAT ARE MUTATIONS
Point Mutations happen at a single point in the DNA. They include
Substitutions – one nitrogen base is changed to another
Insertions – an additional base is inserted into the DNA sequence
Deletions – a base is removed from the DNA sequence

5. What Can We Observe About Mutations?
At the end of your bench is a pot of numbered papers
At random select 4 (one for each person in your group) from the pot
Record the outcome of your mutation in a small table

6. What Can We Observe About Mutations?
Round:1 Flu Epidemic
Colour
Mutation 1
Able to fight off infection better 2
No mutation 3 4
Less able to fight off infection 5
No effect

7. What Can We Observe About Mutations?
Round:1 Intense sunshine and water shortage
Number
Mutation 1
No effect 2
Prone to dehydration and sunstroke 3 4
No mutation 5
Better able to store water and keep cool

8. What Can We Observe About Mutations?
Round 3: Heavy metal pollution
Number
Mutation 1
Able to fight off infection better 2
No effect 3
No mutation 4
Less able to fight off infection 5

9. What Can We Observe About Mutations?
Round 4: Malaria outbreak
Number
Mutation 1
Prevents infection from “taking hold” 2
No mutation 3 4
Less able to fight off infection 5

10. What Can We Observe About Mutations?
Round 3: Hi
Number
Mutation 1
Immune to infection 2
No mutation 3
Immune system severely compromised 4
Less able to fight off infection 5

11. What Can We Observe About Mutations?
Do mutations target specific individuals or genes?
In what ways do mutations effect living organisms?

12. What Are Mutations? The effects of a mutation on an organism can be:
Positive – results in genetic diversity and may have huge benefits for an organism
Neutral – results in little or no change in gene expression
Negative – affects gene expression and protein production. May be very harmful to an organism
The effect a mutation has will depend on the environment

13. Gene Mutations: Substitution
Only affects one amino acid

14. Gene Mutations: Insertion

15. GENE MUTATIONS: Deletion

17. Check for Understanding:
List the three types of gene mutations
Substitution
Insertion
Deletion
Based on what you know of mutations which of the three gene mutations do you think is the most likely to cause harm to an organism and why?
Deletion and/or insertion – these mutations can cause changes to multiple amino acids and can affect protein shape and function

18. GENE MUTATIONS: Frameshift
Deletion and insertion mutations are known as FRAMESHIFT mutations
Can affect the way the triplet code is read
This can affect the amino acid sequence and may alter the protein
Proteins may become unable to perform their function

19. WHAT ARE MUTATIONS THE FAT CAT ATE THE RAT THE FAT HCA TAT ETH ERA T
Examples of Frameshift Mutations:
Insertion: In these examples the words represent amino acids and the sentence represents the protein
THE FAT CAT ATE THE RAT
THE FAT HCA TAT ETH ERA T
Remember we must still follow the triplet code even after mutation – all the triplets that follow the insertion have been frameshifted

20. WHAT ARE MUTATIONS THE FAT CAT ATE THE RAT TEF ATC ATA TET GER AT
Examples of Frameshift Mutations:
Deletion: In these examples the words represent amino acids and the sentence represents the protein
THE FAT CAT ATE THE RAT
TEF ATC ATA TET GER AT
Remember we must still follow the triplet code even after mutation – all the triplets that follow the insertion have been frameshifted

21. Mutagens and Carcinogens
Def: A mutagen is any physical or chemical factor that causes changes (mutations) to an organisms DNA
Chemical Mutagens:
Air fresheners
Alcohol
Cosmetics
Pesticides
Physical Mutagens:
X-rays
UV rays

22. EXAMPLES OF MUTATIONS
Color blindness – mutation on the X chromosome. Very common in males, not common in females
Sickle Cell Anemia – reduces bloods ability to carry oxygen
Blue eyes – A mutation that occurred ,000 years ago. All blue eyed people share a common ancestor!
Down Syndrome – Mutation resulting in extra chromosomes