Question 1

Which of the following best describes the purpose of the hanging drop slide technique in microbiology?

Accepted Answer

To observe bacterial motility in living cells

Question 2

Which of the following movements observed under a microscope would indicate true bacterial motility rather than Brownian motion?

Accepted Answer

Consistent directional movement across the field

Question 3

Why is petroleum jelly applied around the well of a depression slide during the hanging drop slide preparation?

Accepted Answer

To prevent evaporation and seal the coverslip

Question 4

Which of the following statements about bacterial flagella is correct?

Accepted Answer

Flagella are responsible for bacterial motility

Question 5

A student observes a bacterium with a single flagellum at one end. What is the correct term for this flagellar arrangement?

Accepted Answer

Monotrichous

Question 6

Which flagellar arrangement is characterized by flagella distributed all over the bacterial surface?

Accepted Answer

Peritrichous

Question 7

After completing a hanging drop slide, what is the correct procedure for disposing of the coverslip?

Accepted Answer

Soak in bleach for 15 minutes, then dispose in glass waste

Question 8

Which of the following best explains why the iris diaphragm should be adjusted when observing a hanging drop slide?

Accepted Answer

To reduce light intensity and improve contrast

Question 9

A bacterium is observed with tufts of flagella at both ends. What is the correct term for this arrangement?

Accepted Answer

Amphitrichous

Question 10

Which of the following is NOT a reason for observing apparent movement in a hanging drop slide?

Accepted Answer

Gram reaction

Question 11

Why are flagella difficult to see using simple staining techniques?

Accepted Answer

They are too thin to be resolved by light microscopy without special stains

Question 12

Which of the following best describes the difference between Brownian motion and true motility?

Accepted Answer

Brownian motion is due to collisions with water molecules, true motility is active movement by the cell

Question 13

A clinical sample is observed using a hanging drop slide. The bacteria show rapid, independent movement across the field. What can be concluded?

Accepted Answer

The bacteria are motile

Question 14

Which of the following is the correct order of steps for preparing a hanging drop slide?

Accepted Answer

Add petroleum jelly to slide, add bacteria to coverslip, invert slide over coverslip

Question 15

Which of the following best describes the lophotrichous flagellar arrangement?

Accepted Answer

A tuft of flagella at one end

Question 16

If a student forgets to reduce the light with the iris diaphragm while observing a hanging drop slide, what is the most likely consequence?

Accepted Answer

The sample will be too bright, reducing contrast and making motility hard to observe

Question 17

Which of the following equations best represents the relationship between the observed motility and the actual motility of bacteria in a hanging drop slide, considering possible artifacts?

Accepted Answer

$$Observed\ Motility = True\ Motility + Brownian\ Motion + Water\ Currents$$

Bacterial Motility and Flagella: Laboratory Techniques and Structural Arrangements

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