Question

question 5 (10 points)
filter paper disks soaked in household bleach, rubbing alcohol, vinegar and water were all placed on a petri dish inoculated with bacteria and incubated. after two days the petri dishes were removed and studied for changes. what is the control group in this experiment?
a rubbing alcohol
b water
c vinegar
d bleach

Explanation:

In an experiment, the control group is the one that does not receive the treatment being tested (here, substances with antibacterial properties like Bleach, Rubbing Alcohol, Vinegar) and is used for comparison. Water is a neutral substance without antibacterial properties (unlike the others) and serves as the control to see the effect of the other substances on bacteria.

Answer:

b. Water