Using Genetics to Dissect Gene Structure Flashcards
Describe what complementation is
Where two mutations complement each other. When two bacteria are in medium, each containing different mutations for different things. If these mutations are on different genes then they can possibly compliment each other. They can make the required proteins that the other cannot, make up for each others deficiencies.
Describe recombination, and its use in analysing mutations
Recombination takes place during meitotic DNA replication, during the crossing over of chromosomes, as a way to increase genetic variation. The frequency of recombination between two genes is reliance on the distance between the two. The closer together two genes are, the less likely recombination will take place. Can apply the same rationale to mutations within genes, and can then infer the locations of mutations in relation to one another in chromosomes.
Why was it so important to use two E.coli strains in Benzer’s experiments?
To be able to differentiate between the wild-type and the mutants.
What are plaques?
Plaques are holes in colonies of bacteria caused by bacteriophage. Is used as a way to detect the presence of phages.
What was the purpose and the outcome of Benzers experiments
Benzer was analysing mutations in strains of E. coli that made them unable to be killed by phage. He found using complementation analysis that certain mutations were located on the same gene, whilst others were not. Using recombination analysis he was able to map the location of these mutations in relation to one another.
