1. Genetic Errors & Mutations

2. DNA Sequence: TAC – AAG – CTG – CAT – ATT RNA Sequence: AUG – UUC – GAC – GUA – UAA Amino Acid Sequence: Met – Phenylalanine – Aspartic acid – Valine - STOP

3. Point mutation: single base (letter) is changed BAT becomes CATATC becomes GTC Errors Transcription is like reading a book. If you change a letter, it will change the word.

4. Frameshift mutation: insertion/ deletion of a base  changes reading frame Errors Example: “THE CAT SAT” If extra letter “A” is added after “THE” then the sentence will read as “THE ACA TSA T”

5. Errors Silent mutation: results in a codon that codes for same amino acid Example: mRNA codon UCU and UCC BOTH codons code for Serine

6. Errors Nonsense mutation: stop codon is transcribed in place of codon that codes for an amino acid Example: mRNA codon UAC is changed to UAA UAC  Tyrosine UAA  STOP  shortened protein chain

7. Translocation Pieces of chromosome jump to diff. chromosomes

8. Meiosis Review Cell division occurs TWICE - at the end of Meiosis I & Meiosis II

9. Nondisjunction Having an extra chromosome due to mutation in Meiosis

10. Trinucleotide (Triplet) Repeat Expansion A triplet (3) of nucleotides, like CAG, repeat over and over. Protein will be either too long, or not made at all