Post-Lab F Quiz - MIC 206 Post LAb quiz PDF

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MIC 206 Post LAb quiz ...

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11/15/2020

Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

Post-Lab F Quiz Due Nov 15 at 11:59pm

Points 50

Questions 25

Available Nov 12 at 3pm - Nov 15 at 11:59pm 3 days Time Limit 60 Minutes

Instructions IMPORTANT NOTE: If you are color-blind, you should find someone that will be able to describe the colors in some of the images to you while you are taking this quiz. However, their contribution should only be limited to describing the colors and nothing more. This post-lab quizcontains questions regarding the exercises on microscope use and the various staining techniques we studied. Please review these topics and answer the self-assessment questions before starting this post-lab quiz. There are 25 questions worth 50pts. You have 60minutes to complete the test, after which time it will automatically save and submit, regardless of whether you were working on it or not during the 55-minute period. Onlyone attempt is allowedso select your answers carefully and use a computer with a reliable Internetconnection.You can view the correct answers the day following the deadline.

Attempt History LATEST

Attempt

Time

Score

Attempt 1

24 minutes

46.67 out of 50

 Correct answers will be available Nov 17 at 12am - Nov 24 at 12am. Score for this quiz: 46.67 out of 50 Submitted Nov 15 at 6:41pm This attempt took 24 minutes.

Question 1

https://canvas.asu.edu/courses/60378/quizzes/396736

2 / 2 pts

1/16

11/15/2020

Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

Which of the below best describes the cellular morphology of the bacteria seen in this image?

streptobacilli

Question 2

2 / 2 pts

What is the purpose of iris diaphragm in a Compound light microscope?

To regulate intensity of light entering the lenses.

https://canvas.asu.edu/courses/60378/quizzes/396736

2/16

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

4 / 4 pts

Question 3

Match the following terms with their correct descriptions.

Parfocal

when switching objective

Magnification

the extent an object is in

Resolution

the ability to distinguish

Refractive index

the degree at which an o

Question 4

2 / 2 pts

What is the purpose of adding a drop of immersion oil on the smear while viewing it on the oil immersion objective lens?

The refractive index of oil is same as that of the glass, so it prevents light refraction.

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3/16

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

When light passes from one medium to another , such as from glass to air, it is bent away from its path that means it is refracted. This can be prevented by providing the same medium to light as glass before it enters into the objective lens by adding a drop of immersion oil. immersion oil has the same refractive index as the glass ( what is around 1.5-1.6) ,so the gap between the slide and the lens that contains air ( with Refractive index of 1) is filled with immersion oil with oil immersion objective lens.

Question 5

2 / 2 pts

Acid-fast organisms do not take up stains easily because:

they have large amounts of mycolic acid in their cell walls

Question 6

https://canvas.asu.edu/courses/60378/quizzes/396736

2 / 2 pts

4/16

11/15/2020

Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

Bacterial endospores have a very thick protective covering called a spore coat that makes them impermeable to many molecules. How can the endospores be stained if they are impermeable to many compounds?

The primary dye is driven into the spore by the application of heat

Partial

Question 7

1.33 / 2 pts

Which of the following is correct about acid fast staining? Select all the answers that are correct.

It is a very useful method to identify bacteria that belong to genus Mycobacterium and Nocardia.

https://canvas.asu.edu/courses/60378/quizzes/396736

5/16

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

Acid alcohol is used as a decolorizer .

Question 8

1 / 1 pts

Endospore production is a method of reproduction for bacteria.

False

Question 9

2 / 2 pts

In an aqueous environment with a nearly neutral pH, the bacterial cells will carry an overall __________ charge.

negative

Question 10

2 / 2 pts

You are preparing a smear for a Gram stain. After spreading the bacterial cells on a microscope slide, your immediate next step is to:

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6/16

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

dry the smear

Question 11

2 / 2 pts

Iodine serves as a mordant in the Gram stain procedure. What is the best explanation of iodine's role in the Gram stain?

Iodine binds to the primary stain and forms a large crystal violet-iodine complex that easily becomes trapped in the cell wall.

Question 12

2 / 2 pts

The correct application of which of the following is considered the most critical in the success of a Gram staining procedure?

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7/16

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

the decolorizer.

Question 13

2 / 2 pts

Which of the following bacteria are capable of producing endospores?

Bacillus and Clostridium

Question 14

2 / 2 pts

Which of the following is NOT a true statement about a simple stain?

A simple stain involves the use of two or more dyes.

https://canvas.asu.edu/courses/60378/quizzes/396736

8/16

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

2 / 2 pts

Question 15

Which of the following is NOT a property of bacterial capsules?

bind negatively charged dyes

Question 16

1.5 / 1.5 pts

If the safranin step was omitted in a Gram stain, Gram positive cells would be ________ at the end of the procedure (assuming everything else was done correctly).

purple

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

Question 17

1.5 / 1.5 pts

If the safranin step was omitted in a Gram stain, Gram negative cells would be ________ at the end of the procedure (assuming everything else was done correctly).

colorless

Question 18

2 / 2 pts

The total magnification of a specimen on a microscope set up with 15X ocular objectives and 4X objective in place would be _________ fold. Type your final calculated number only in the following box.

60

Correct!

Question 19

2 / 2 pts

Cathy performs several endospore stains, but can’t seem to get it correct. What was the technical error if her stains of Clostridium tetani result in https://canvas.asu.edu/courses/60378/quizzes/396736

10/16

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

colorless endospores and red bacilli?

She forgot to heat the slides while applying the primary stain.

Incorrect

Question 20

0 / 2 pts

Cindy does a gram stain on her unknown. She views the slide under the microscope and sees the following images. What is the gram reaction of her unknown?

Gram negative

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11/16

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

You should not decide on a gram reaction of an unknown if any of your controls on the same slide do not look right. In this case, does the positive control look right to you?

Question 21

2 / 2 pts

Ed is trying to perfect his Gram stain, but keeps making technical mistakes. Predict the effect of Ed's mistake on his Gram stain if he left the decolorizer on his slide for over five minutes. Your answer needs to include both a result and a reason from the following selections for full credit (be careful, incorrect answers lower your score).

Reason: Even the G+ cells will release the CV-iodine complex if decolorized for too long

Result: both G+ and G– cells look pink

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12/16

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

Excellent!

Question 22

2 / 2 pts

Endospore and Acid Fast stains are both heated during the application of the primary stain. Why is acid-fast stain heated?

To weaken the waxy layer in the cell wall temporarily to drive the primary stain through it.

Partial

Question 23

1.33 / 2 pts

What kind of staining technique was used to generate this slide? Select one or more correct answers by deciding whether each option is applicable to this staining technique (caution: incorrect answers will lead to point deductions).

https://canvas.asu.edu/courses/60378/quizzes/396736

13/16

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

Capsule stain

Structural stain

Question 24

2 / 2 pts

What kind of staining technique was used to generate this slide? Select one or more correct answers by deciding whether each option is applicable to this staining technique (caution: incorrect answers will lead to point deductions).

https://canvas.asu.edu/courses/60378/quizzes/396736

14/16

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

Endospore stain

Structural stain

Question 25

2 / 2 pts

Your microscope is parfocal. What advantage does it have over one that is not parfocal?

https://canvas.asu.edu/courses/60378/quizzes/396736

15/16

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Post-Lab F Quiz: MIC 206: Microbiology Laboratory (2020 Fall)

You can switch objectives while the specimen remains relatively in focus.

Quiz Score: 46.67 out of 50

https://canvas.asu.edu/courses/60378/quizzes/396736

16/16...