Question

1.2.3 attack of the superbugs - conclusion questions
complete: __ correct: on time: total score: __/4

1. what was the purpose of culturing bacteria on these four plates?
2. how did your predicted results compare to your observed results?
3. why did the e. coli i strain grow on both the lb agar plate and the lb agar plate with streptomycin but not grow on the lb agar plate with ampicillin?
4. why did neither strain grow on the plate containing both streptomycin and ampicillin?

Explanation:

1. Culturing bacteria on plates is often to study growth under different conditions, test antibiotic - resistance, or observe genetic traits.
2. Comparing predicted and observed results helps assess the accuracy of hypotheses and experimental design.
3. The E. coli strain may be resistant to streptomycin but sensitive to ampicillin, which is why it grows on one plate with streptomycin but not on the plate with ampicillin.
4. The lack of growth on the plate with both antibiotics may be due to the combined inhibitory effects of streptomycin and ampicillin, or the strains may not have resistance to either or both of these antibiotics.

Answer:

1. To study bacterial growth under different conditions (such as antibiotic - presence), test antibiotic - resistance, or observe genetic traits related to growth.
2. Compare to assess hypothesis and experimental design accuracy.
3. The strain is resistant to streptomycin but sensitive to ampicillin.
4. Combined inhibitory effects of the two antibiotics or lack of resistance to either/both.