1. Unit 6 Notes: Mutations

2. DNA Mutations Mutations: Any change in the sequence of nitrogenous bases of DNA. Causes: – Mutagens = factors that change chemical nature of DNA Cell errors Chemical / UV light exposure Radioactive substances X-rays

5. Types of Mutations Point mutation: Change 1 base along DNA sequence. – Substitution  Replace 1 base with a different one.

6. Results of Point Mutations Missense: Mutation changes the type of protein made. Nonsense: Mutation causes premature stop in translation. Silent: Changes bases, but has no effect on protein made.

7. Types of Mutations Frameshift mutation: Any Insertion or Deletion mutations which shift the bases, changing the amino acid sequence. – Insertion  Add 1 extra base – Deletion  Remove 1 base

9. Example Diseases Cause by Mutations Color blindness  Point mutation Hemophilia  Point mutation – Blood doesn’t clot, lacks clotting proteins Sickle-cell disease  Point mutation

10. Mutations – Visual Learning https://www.youtube.com/watch?v=GieZ3pk9 YVo https://www.youtube.com/watch?v=GieZ3pk9 YVo Http://education- portal.com/academy/lesson/how-point- mutations-insertions-and-deletions-affect- dna.html Http://education- portal.com/academy/lesson/how-point- mutations-insertions-and-deletions-affect- dna.html https://www.youtube.com/watch?v=0wrNxCG KCws https://www.youtube.com/watch?v=0wrNxCG KCws