BIOL 241 2/12 Discussion Section Sid & Dan

What is a compensatory mutation?

• A mutation that allows an organism to adapt to new surroundings.

• Another term for a beneficial mutation.

• A mutation that receives money from an employer as a salary.

• A mutation that corrects a loss of fitness present in earlier mutations.

What is the name of the plate that is used for measuring evolutionary changes in e.coli in this paper?

• MINI

• MEGA

• GIGA

• MEESA

What were the names of the antibiotics used in the experiment?

• Trimethoprim

• Cephalexin

• Azithromycin

• Ciprofloxacin

What was the model organism used in the study?

• H. pylori

• 
• E. coli

• S. cerevisiae

True or false: compensatory mutations were mostly able to outcompete their parent during the course of the experiment.

• True

• False

What was the name of the gene that all hypermutator populations had mutations in?

• dnaQ

• mutD

• folA

• pitA

What would happen if the MEGA plate used in the experiment was wider (leading to more bacteria progressing along the front)

• Bacteria would mutate at a higher rate.

• There would be a larger population of bacteria

• No change in the results

• There would be more total mutations in the population

Name one cost of mutations that initially enabled increased resistance to antibiotics mentioned in the paper.

• excessive mutation rates

• reduced growth

• decreased size

• there are no costs to evolving increased resistance

Which concentration of antibiotic for the intermediate step in figure 2 best equips the bacteria to reproduce in high concentrations of antibiotics?

• 0 MIC units

• 3 MIC units

• 30 MIC units

• 3000 MIC units

What would happen if each step in the MEGA plate (each with varying concentrations of antibiotic) were longer in length?

• More overlap in lineages between bacteria

• No change in the results

• Reduced ability for bacteria to adapt to successively higher concentrations

• Reduced genetic diversity in the bacterial population