Question

5. Which of the following objects, if touched to the surface of trypticase soy agar (TSA) within a Petri plate, would likely exhibit bacterial growth?

A. Your best friends nose

B. A strangers cell phone

C. A sterile swab

D. All of the above

E. A and B

  6. Which of the following is/are true of aseptic technique during streak plating?

A. It prevents airborne contaminants from entering the test tube culture you are working with.

B. It prevents airborne contaminants from entering the Petri plate.

C. It prevents cells from your culture from being left on the loop (to be touched by you or someone else the next time the loop is used).

D. All of the above

E. B and C

11. The primary function of the simple stain using methylene blue is to…

1. Distinguish between Gram-positive and Gram-negative wall and membrane(s) composition and organization.
2. Elucidate the shape of a bacterial capsule.
3. Elucidate the shape of the cell itself.
4. A and B
5. B and C

13. If safranin was replaced with methylene blue in the Gram stain, then Gram-negative E. coli would appear?

A. Bluish-Purple

B. Green

C. Pink

D. Red

E. Yellow

  

Answer 1

1. A petri plate containing TSA will allow the growth of bacterial strain if samples were introduced to it. considering the given options, all of the given objects contains different types of bacteria on them. a persons nose contain bacteria. a cellphone contains bacteria on it. but if they touched or introduced to agar in the petriplate they may contaminate the agar medium and resists the growth of the bacteria.
hence the answer will be a sterile cotton swab which will be used to obtain the sample and touches on the agar medium which allows the groth of bacteria in the petri plate or slants.

5. aseptic technique during the streak plate method involves all the given options and the answer will be all the above.

11.methylene blue is a bacterial stain used to determine the morphology of the bacteria that is to determine the shape and to observe the internal structues of the bacteria. by the given options the answer would be elucidating the shape of cell and as well as bacterial capsule.