2. GENE REGULATION Gene regulation: The ability of an organism to control which genes are transcribed in response to the environment.

3. MUTATION Mutation: a permanent change that occurs in a cell’s DNA. Can range from changes in a single base pair (Ex: An A instead of a C) in the coding sequence of DNA to the deletion of large pieces of chromosomes. http://www.youtube.com/watch?v=efstlgoynlk

4. POINT MUTATION Involve a chemical change in just one base pair. A point mutation is exchanged for another is called a substitution.

5. POINT MUTATION Missense mutation: codes for the wrong amino acid. Nonsense mutation: change the codon for an amino acid to a stop codon. Silent mutation: a substitution that does not change the amino acid. Normal Sentence: THE BIG FAT CAT ATE THE WET RAT Missense Mutation: THE BIZ FAT CAT ATE THE WET RAT Nonsense Mutation: THE BIG RAT.

6. INSERTION MUTATIONS Insertions are additions of a nucleotide to the DNA sequence. This changes the multiples of three in the DNA sequence from the point of the insertion.

7. DELETION MUTATIONS Deletion mutations remove a nucleotide from the DNA sequence. This changes the multiples of three in the DNA sequence from the point of the insertion.

8. INSERTION & DELETION MUTATIONS Normal Sentence: THE BIG FAT CAT ATE THE WET RAT INSERTION: THE BIG ZFA TCA TAT ETH EWE TRA DELETION: THB IGF ATC ATA TET HEW ETR AT These mutations are called frameshift mutations because they change the “frame” of the amino acid sequence.

9. DUPLICATION MUTATION A duplication mutation is the repeat of one or more codons.

10. DUPLICATION MUTATION Normal Sentence: THE BIG FAT CAT ATE THE WET RAT Duplication: THE BIG FAT FAT CAT ATE THE WET RAT

11. Original DNA Sequence : T A C A C C T T G G C G A C G A C T … mRNA Sequence: A U G, U G G, A A C, C G C, U G C, U G A Amino Acid Sequence: Met Try Asp Arg Cys Stop

12. Mutated DNA Sequence #1 T A C A T C T T G G C G A C G A C T … What’s the mRNA sequence? A U G, U A G, A A C, C G C, U G C, U G A (Circle the change) What will be the amino acid sequence? Met STOP Asp Arg Cys Stop.... Will there likely be effects? YES What type of mutation is this? Base substitution of T for C causing a NONSENSE mutation.