1. MUTATIONS 12.4

2. I. VOCABULARY A. Mutation- Any change in the __________ sequence. 1. Mutations in body cells may cause _______ to be made wrong or not at all.

3. I. VOCABULARY A. Mutation (cont.) 2. When the body cell divides, new cells will have the same mutation. a. May cause cells to grow & divide rapidly (_______)

4. I. VOCABULARY A. Mutation (cont.) b. Body cell mutations are NOT passed to the _____________. c. A build up of mutated cells may cause ________

5. I. VOCABULARY A. Mutation (cont.) 3. Mutations in sex cells ARE passed to the offspring a. Embryo may ___________ b. May have _____________ c. Could be beneficial!

6. I. VOCABULARY B. Point Mutation- A change or SUBSTITUTION of a single base pair of DNA. 1. AKA “_____” Mutations 2. May or may not change the amino acid/_________

7. I. VOCABULARY B. Point Mutation (cont.) 3. Example: THE DOG BIT THE CAR THE DOG BIT THE CAT

8. I. VOCABULARY C. Frameshift Mutation- Mutation in which a single base is __________ or __________. 1. Causes the entire DNA sequence to shift 2. Generally more __________!

9. I. VOCABULARY 3. Example: THE DOG BIT THE CAT (mutation: Delete 1 st G) THE DOB ITT HECAT

10. I. VOCABULARY D. Chromosomal Mutation- Mutation that occurs at the _____________ level. 1. Changes gene distribution in _____________ 2. Chromosomes break off or rejoin incorrectly.

11. I. VOCABULARY a) Deletion (one base taken away) b) __________ (one base added) c) ___________ (bases are flipped around) d) Translocation (a piece breaks off and joins another __________)

12. II. CAUSES OF MUTATIONS A. Mutagen- Any agent that can cause a change in _________.

13. II. CAUSES OF MUTATIONS A. Mutagen-(cont.) 1. Radiation (X rays, UV light, cosmic rays, nuclear radiation). a. Radiation badges & __________ monitor exposure in nuclear power plants

14. II. CAUSES OF MUTATIONS A. Mutagen-(cont.) 2. Chemical (dioxins, asbestos, benzene & formaldehyde) a. Often found _________

15. III. REPAIRING DNA A. DNA is often repaired ____________! B. Enzymes “proofread” DNA and replace incorrect ______________

16. III. REPAIRING DNA 1. Greater exposure to mutagens such as UV light makes it hard for ________ to keep up. a. Humans should avoid mutagens if possible!!!

17. IV. REVIEW Define mutationDefine mutation Which is more dangerous, point mutations or frameshift mutations?Which is more dangerous, point mutations or frameshift mutations? Why are point mutations often called “silent”?Why are point mutations often called “silent”?

18. IV. REVIEW What is a chromosomal mutation?What is a chromosomal mutation? Give an example of a mutagen.Give an example of a mutagen. What “proofreads” DNA for mistakes?What “proofreads” DNA for mistakes?