1. Midterm structure One Diagram (Bubble sheet) 10-15 Multiple choice (Bubble sheet) 10-12 Short answer questions (Bubble sheet) Two essay question (choice 2 of 3)

2. Content covered My lectures I stress understanding rather than memorizing detail.

3. The Process of Science Observation – Question – Logic – if... then... Hypothesis – H 0 (no difference between observed and expected) and H 1 (observed and expected are different) Experiment – Result – disconfirmation or confirmation of hypothesis alternative hypotheses Remember proof in science is impossible

4. Sequence of events. 1857 - Darwin - Characteristics of parents passed on to young. 1869 – Friedrich Miescher – discovered ‘nuclein’ (DNA)‏ 1882 – Walther Flemming – Chromosomes 1920’s - Levene – DNA is a polymer (scaffolding) (tetranucleotide theory)‏ 1928 – Griffith – transforming principle 1930’s – Hammerling – Acetabularia transplant 1941 – Beadle and Tatum – one gene one enzyme hypothesis 1944 – Avery – DNA, not protein, responsible for transforming principle

5. Sequence of events. Cont’d. 1952 – Hershey and Chase – confirmed Avery’s results using bacteriophages. 1952 – Briggs and King – nuclear transplant exp. in frogs 1953 – Rosalind Frankling – x-ray diffraction of DNA 1953 – Watson and Crick – DNA model 1953 – Sanger – amino acid sequence for Insulin 1955 – Chargaff – A=T and G=C

6. Rosalind Franklin – X-ray diffraction Watson and Crick – double helix Meselson-Stahl – DNA replication is semiconservative Ingram – single amino acid substitution can change the action of the protein. DNA replication –leading and lagging strands, origin of replication proteins are linear sequences of amino acids Genetic code – 3 base -> codons Transcription, translation differences between prokaryotes and eukaryotes

7. mRNA, tRNA and rRNA Introns and exons - Genetic Engineering Phages and plasmids Restriction endonucleases – sticky ends Gel electrophoresis DNA libraries Polymerase Chain Reaction (PCR)‏ pros and cons of genetic Engineering