Chapter 9: DNA structure and analysis (genetics)-Questions and Answers

Chapter 9: DNA structure and analysis (genetics)-Questions and Answers What are the four major characteristics that genetic material must have? - ANSWER-replication storage of info expression of info variation by mutation what is the central dogma of molecular genetics? - ANSWER-DNA--RNA--protein the process of DNA turning into RNA is transcription the process of RNA to protein is translation what did Phoebus A Levene propose about the makeup of DNA in 1910? - ANSWER-postulated DNA had approx equal amounts of 4 similar molecules; also proposed that identical groups of nucleotides are repeated over and over What is transformation? - ANSWER-the heritable change of a cell of an organism brought about by exogenous DNA. known to occur naturally and also used in recombinant DNA What is the basic outline of Dr. Frederick Griffith's experiment and what were the implications - ANSWER-experimented with different strains of diploccocus pneumoniae, one virulent (with glycocalyx) and one non virulent(no glycocalyx). he proceeded to inject mice with the different strains. obviously, the ones injected with the live virulent strains would die, but when they were heat killed, the mice lived. when injected with nonvirulent bacteria, the mice would live. but when the mice were injected with heat killed virulent bacteria and then live nonvirulent bacteria. the mice would die. upon inspection. the live bacteria that were initially nonvirulent, had become virulent. there was some transforming principle in the virulent strain. What experiment did Oswa;d Avery, Colin Macleod, and Maclyn McCarty conduct and what were the implications - ANSWER-they proved that the transforming principle that had been observed in Griffith's experiment was DNA. they concluded this by taking smooth, virulent bacteria (glycocalyx), extracting the carbohydrates, lipids and proteins. they then mixed ot with non-virulent bacteria and saw that the nonvirulent bacteria were still transformed. they then treated the virulent bacteria with a protease to get rid of protein. the then mixed that bacteria with nonvirulent bacteria and again saw that the nonvirulent bacteria were still being transformed. they then treated the virulent bacteria with a ribonuclease, to get rid of the RNA. again they saw that the virulent bacteria were still transforming the nonvirulent bacteria. they finally treated the virulent bacteria with a deoxyribonuclease to get rid of