1. What do you think of when you hear the word “mutation”?
SPONGE 6
What do you think of when you hear the word “mutation”?
Are they always bad?
Give me an example

2. Mutations?

3. Not all mutations are bad
Most do have negative effects

4. KEY CONCEPT Mutations are changes in DNA that may or may not affect phenotype.

5. A mutation is a change in an organism’s DNA.
Many kinds of mutations can occur, especially during replication.

6. A point mutation substitutes one nucleotide for another.
GENE MUTATIONS
A point mutation substitutes one nucleotide for another.
GAT CTC
GAT CAC
mutated
base

7. Example of a point mutation
Sickle cell anemia

8. THE CAT ATE THE RAT THC ATA TET HER AT….
2) A frameshift mutation inserts or deletes a nucleotide in the DNA sequence.
THE CAT ATE THE RAT
THC ATA TET HER AT….

9. Example of a frame shift mutation:
Tay–Sachs disease
around 6 months of age
Nerves start deteriorating
Child becomes blind, deaf, and unable to swallow
Death usually occurs before the 4th year

10. Chromosomal mutations
affect many genes.
may occur during crossing over

11. 1) Gene duplication results from unequal crossing over.

12. 2) Translocation results from the exchange of DNA segments between nonhomologous chromosomes.

13. Mutations may or may not affect phenotype (looks).
Chromosomal mutations tend to have a big effect.
Some gene mutations change phenotype.
may cause a premature stop codon.
may change protein shape or the activation site.
may change gene regulation.
Ex: down syndrome

14. Some gene mutations do not affect phenotype.
A mutation may be silent.
A mutation may occur in a noncoding region.
A mutation may not affect protein folding or the active site.
Ex: Cystic Fibrosis- caused by a deletion
blockage
no blockage

15. Mutations in body cells do not affect offspring.
Mutations in sex cells can be harmful or beneficial to offspring.
Natural selection often removes mutant alleles from a population

16. CCR5 32 is a deletion thought to resist the bubonic and pneumonic plague as well as HIV
Beneficial mutations
Mutations that cause resistance to antibiotics

17. Conjoined Twins
Chang and Eng Bunker
Born in 1811
Married sisters
Had 21 children between them
In modern times, they could have easily been separated
Died on the same day in 1874
Chang contracted Pneumonia and died in his sleep- Eng refused to be separated from his dead twin and died several hours later.

18. Mutations caused by Mutagens
Radiation