18 Questions
What is the main purpose of this experiment?
To detect resistance resulting from a mutation in a bacterial gene
Why are bacterial mutations more easily detectable compared to mutations in diploid organisms?
Bacteria have only one unpaired chromosome
What is the typical range of mutation rates in bacterial cells?
1 in 10^4 to 1 in 10^12 divisions
How do bacterial mutations provide a selective advantage?
By allowing the bacteria to survive in the presence of antimicrobial agents
What is the role of streptomycin in this experiment?
It is used to inhibit protein synthesis in the bacterial cell
Why is the combination of E. coli and streptomycin convenient for illustrating chromosomal resistance?
E. coli becomes resistant to streptomycin with just one mutation
What is the purpose of adding histidine to the top agar in the Ames test?
To promote mutagenesis by allowing bacteria to undergo multiple cell divisions
What might happen if the top agar is not vortexed properly before pouring over the glucose minimal salts agar?
Stippling of the top agar will occur
What is the significance of a halo of densely packed revertant colonies around the disk in the Ames test?
It suggests the presence of mutagenic agent
What could be the consequence of not moving quickly enough when adding bacteria to the top agar in the Ames test?
Stippling of the top agar
Why is it necessary to incubate the plate at 37°C for 48 hours after adding the test reagent in the Ames test?
To allow time for mutation and colony formation
Why are additional tester strains used in routine testing of the Ames test?
To accommodate different types of chemical compounds
According to the passage, why are bacteria used for screening chemical compounds for potential carcinogenesis?
The fact that carcinogenic compounds induce increased rates of mutation in bacteria.
What is the conventional method for determining if a chemical substance is carcinogenic?
Injecting the material into animals and looking for tumor development.
What is the advantage of using the Ames test over the conventional animal testing method?
The Ames test is cheaper and easier to perform than animal testing.
What is the role of the Ames test in determining carcinogenicity?
It serves as a screening test for detecting potentially carcinogenic compounds.
What is the correlation between mutagenicity and carcinogenesis mentioned in the passage?
The correlation between mutagenicity and carcinogenesis is around 83%.
What bacterial strain is used in the Ames test, and what is its characteristic?
A strain of Salmonella typhimurium that is auxotrophic for histidine.
Explore the detection of resistance resulting from a mutation in a gene on the bacterial chromosome. Learn about the varying rates of mutations in bacterial cells and the impact of their haploid nature on mutation occurrence.
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