13.1 The Structure of DNA I. _____: The Genetic Material A. _________are the instructions for inherited _________. B. Before the _______ we didn’t know what _________ were made of. C. __________ 1. Deoxyribonucleic _______ a. the primary material in _______ that causes recognizable, inheritable ______________

b. made up of _____ different subunits c. early scientists thought it too ______ to be _________ material II. Searching for the Genetic Material A. ______ Frederick __________, an English public health ______________ 1. Working with __________ – a substance of killed or weakened microorganisms used in the body to produce __________ 2. Chose ______ strains of _________

a. the S-type had a ________ that. made it ________ – able to cause a. the S-type had a ________ that made it ________ – able to cause disease & the R-type had no __________ 3. The Experiment a. S-type ________ mice but did not when it was __________ killed b. R-type did not _____ mice, when _______ with heat killed S-type it became ___________ 1. This proved that R-type underwent a ______________ 4. _____ it was announced that _____ was genetic material

B. 1940’s, Oswald ________ 1. Wanted to determine whether the transforming agent was ______, ______, or ______. 2. Concluded that _____ is responsible for transformation. C. _________ and ________ 1. 1952 conducted an experiment with bacteriophage – _____ that infects _________ a. T2 bacteriophage attaches to bacteria and injects ________ info.

b. Once inside bacteria, virus. _________ hundreds of itself & b. Once inside bacteria, virus _________ hundreds of itself & eventually cause the bacteria to ________ c. DNA contains ___________ – given __________ treatment to track d. Protein has ______ – given ___________ treatment to track 2. Radioactive ___________ found inside bacteria after experiment 3. Proved that _____ was genetic info carrier and not _________

III. The Shape of DNA A. ______________ 1. long thin molecule that makes up ______ 2. ____ parts a. ___________ group b. ___ carbon sugar – called deoxyribose c. _________ base – could be one of four 1. Purines – has double carbon ring a. _________ b. _________ 2. Pyrimidines – has single carbon ring

B. Erwin Cargaff created base paring rules 1. adenine --- ___________ 2. guanine ---- __________ IV. Discovering DNA’s Structure A. 1952 Maurice _________ and Rosalind __________ use x-ray _____________ 1. determine that DNA is a __________ _________ of 2 or 3 coiled chains B. 1953 ____________ and __________ 1. discovered 3 dimensional double helix or “__________ ____________” 2. DNA looks like twisted __________ 3. Each side of the ladder is ______________ ex.- T C G A A C T __ __ __ __ __ ___ ___