FREE SCIENCE AND STUDY GAMES ABOUT MICRO-LAB

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FREE SCIENCE AND STUDY GAMES ABOUT MICRO-LAB

EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -13 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation

Question 1: What is the use of Petri plates in microbiology?

Answer:

They provide a large surface area for solid culture media in an easily stored container Question 2: Why is the swab first moistened in sterile water before sampling a dry surface?

Answer:

the swab must be moist to adequately pick up microbes.Question 3: Did all the organisms living in or on the environments sampled grow on your nutrient agar? Why or why not?

Answer:

No because we didnt satisfy all the nutritional and environmental requirements

Question 4: What is human body temperature in degrees celcius?

Answer:

37 degrees celcius

Question 5: Why is condensation on the agar undesirable?

Answer:

Bacteria will be in a liquid suspension instead of forming discrete colonies and it will spread the microbes on the surface Question 6: Why is agar preferable to gelatin as a solidifying agent in culture media?

Answer:

• It liquefies at 100 degrees Celsius and stays in a liquid state until cooled to 40 degrees Celsius.

• Once hardened, it stays solid up to 100 degrees Celsius.

• Few microbes can metabolize the agar, so it remains solid.

Question 7: How could you tell whether the turbidity in your nutrient broth was from a mixture of different microbes or from the growth of only one kind of microbe?

Answer:

By sub-culturing the nutrient broth onto the surface of a nutrient agar plate. The plate will create discrete colonies & if they differ u can tell.Question 8: Why is it necessary to keep the flask at an angle through this procedure?

Answer:

To minimize contamination from the air

Question 9: What quantity of agar will you need to add?

Answer:

1.28 g

Question 10: To what temperature will it have to be heated?

Answer:

100 degrees celcius

Question 11: What are bacteria using for nutrients in nutrient agar?

Answer:

Peptone and beef extract

Question 12: What is the purpose of the agar?

Answer:

The agar is the solidifying agent.

Question 13: What effect does the agar have on the culture medium?

Answer:

It solidifies the medium