MBIO 0312

Table of Contents: 00:00 - Mutation: Changes in the Genetic Material 03:30 - Base substitution (point mutation) One base is substituted for another Occurs during replication 05:49 - Point Mutations 07:26 - Point Mutations 09:30 - Mutations 16:02 - The Frequency of Mutation 18:36 - Mutagens 20:05 - Chemicals Nitrous acid By-product of fossil fuel burning Oxidizes adenine  binds with cytosine (AT  CG) 22:00 - Chemicals 22:40 - Mutagens 26:52 - Light-repair - Photolyases separate thymine dimers Nucleotide excision repair 29:07 - Identifying Chemical Carcinogens 32:50 - Identifying chemical carcinogens 34:37 - Each sample is poured onto a plate of medium lacking histidine. The plates are then incubated at 37°C for two days. Only his- bacteria that has mutated back (reverted) to his+ will grow into colonies. 35:20 - The numbers of colonies on the experimental and control plates are compared. 40:32 - Identifying Mutants 40:32 - Handle 40:32 - Handle 40:32 - Handle 40:33 - Handle 40:33 - Genetic Transfer and Recombination 42:40 - Mechanisms for genetic transfer in bacteria 42:57 - Figure 8.24 43:46 - Figure 8.24a: Living encapsulated bacteria 44:39 - Figure 8.24b: Living nonencapsulated bacteria 45:38 - Figure 8.24c: Encapsulated bacteria, killed by heat 46:28 - Figure 8.24d: Living nonencapsulated bacteria and heat-killed encapsulated bacteria 48:39 - Figure 8.25: The mechanisms of genetic transformation in bacteria 50:40 - 53:45 - Mechanisms for genetic transfer in bacteria 54:51 - F+ cells - donor cells that carry plasmid (F factor) F- cells – recipient cells 59:25 - Hfr cells – F factor integrated into the chromosome 01:00:59 - Replication and transfer of part of the chromosome 01:02:18 -