Assignment: Disinfectants, Antiseptics, & Antibiotics

1. True or false: Microorganisms are living organisms that are too small to be seen with the naked eye but are visible under a microscope.

2. Matching: Write the letter of the corresponding definition next to its term.

____ Non-pathogenic A. Medicinal product ingested to kill bacterial infections

____ Pathogenic B. Do not cause harm or disease to their host

____ Opportunistic C. Used on inanimate objects to prevent spread of bacteria

____ Disinfectants D. Will induce infection or disease into their host

____ Antiseptics E. Take advantage of host with weakened immune system

____ Antibiotics F. Disinfectants that are safe for humans to use on skin

3. All of the following are downsides to disinfecting EXCEPT:

a. Antibiotics given at an early age may lead to autism.
b. Overuse can lead to the creation of stronger, resistant bacteria.
c. Could be killing non-pathogenic bacteria, leaving room for opportunistic bacteria to attack.
d. Many disinfectants are eye, skin, and respiratory irritants.

4. Calculate the zone of inhibition using the following data:

Total diameter (no bacterial growth) = 3 mm
Disc diameter = 2 mm

5. Based on your calculation, is the bacteria susceptible to the disinfectant or resistant? Justify your answer.

6. To determine which disinfectant was most effective in preventing the spread of E.coli, the zone of inhibition was calculated after inoculating the bacteria with (1) just water, (2) Clorox, (3) Lysol, and (4) Pine Sol. Identify the: (4 points)

Independent Variable (Hint: what are we changing?) ___________________________

Dependent Variable (Hint: what will we measure?) _____________________________

Control Group (Hint: this is the baseline test) _________________________________

Experimental Group(s) ___________________________________________________