2. Mutations

3. A mutation is a mistake in the cell’s DNA. GTTACG  GGTACG

4. DNA contains the information on how to make proteins. Codons of the mRNA will code for a specific amino acid.

5. The order and length of the amino acid chain determine how it is folded and shaped. If any of the amino acids are changed or the length is changed, the shape is different. The protein’s function may change or not work at all.

6. Mutations are only passed on to your offspring if they occur in your gametes (egg or sperm) Mutations that occur in your body cells may cause cancer.

7. Types of Mutations: Substitution (point mutation: change in one nucleotide)

8. Examples Cystic fibrosis Sickle Cell Disease GAG = glu GTG = val One amino acid in the protein hemoglobin changes the shape of the cell

9. Silent Mutation:

10. Insertion This causes a frameshift mutation. All the previous codons are now changed into different codons and therefore, different amino acids. (also known as missense mutation)

11. Multiple insertions. A gene may be duplicated.

12. Deletion: A nitrogen base is deleted and a frameshift mutation occurs.

13. A gene may be deleted.

16. Inversion The order of nitrogen bases can be switched around. A few amino acids may change. Genes may switch places. May not be expressed properly.

17. What causes mutations? Induced mutations: Toxic chemicals and radiation

18. Examples of plants that were produced via mutation breeding are given in the table below. CropCultivar NameMethod Used to Induce Mutation riceCalrose 76gamma rays wheat Abovesodium azide Lewisthermal neutrons oatsAlamo-XX-rays grapefruit Rio Redthermal neutrons Star Rubythermal neutrons burmuda grass Tifeaglegamma rays Tifgreen IIgamma rays Tift 94gamma rays Tifway IIgamma rays lettuce Ice Cubeethyl methanesulphonate Mini-Greenethyl methanesulphonate common bean SeafarerX-rays SeawayX-rays lilacPrairie Petitethermal neutrons St. Augustine grass TXSA 8202gamma rays TXSA 8212gamma rays

19. Spontaneous mutations Mistakes in DNA replication. Your DNA contains 3 billion base pairs. These are copied every time you make a new skin cell, liver cell, stomach cell…. Enzymes check the DNA to make sure there are no mistakes in the copying process.

20. But…. No process is 100% accurate. About one in every 50 million nucleotides has a mutation occur. This means every new cell contains about 120 new mutations!

21. Worried? Don’t be… As much as 97% of your DNA doesn’t code for proteins. We don’t know what this DNA is for. Also, Silent Mutations occur which don’t change the protein.

22. Are all mutations bad? No, some are good. Antibiotic resistance in bacteria Sickle cell resistance to Malaria

23. Resistance to artherosclerosis Immunity to HIV Lactose tolerance

24. Blue Skin… (diaphorase deficiency)

25. Werewolf syndrome (congenital generalized hypertrichosis)