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1 | |
Thirty-six colonies grew in nutrient agar from 1.0 ml of sample withdrawn from a solution diluted to 10-5 in a standard plate count procedure. How many cells were in the original sample? |
| | A) | 360 |
| | B) | 3,600 |
| | C) | 360,000 |
| | D) | 1,800,000 |
| | E) | 3,600,000 |
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2 | |
Thirty-six colonies grew in nutrient agar from 0.1 ml of sample withdrawn from a solution diluted to 10-3 in a standard plate count procedure. How many cells were in the original sample? |
| | A) | 360 |
| | B) | 3,600 |
| | C) | 360,000 |
| | D) | 1,800,000 |
| | E) | 3,600,000 |
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3 | |
Which of the following is the best definition of generation time? |
| | A) | The length of time it takes for lag phase. |
| | B) | The length of time it takes for a population of cells to double. |
| | C) | The maximum rate of doubling divided by the initial count. |
| | D) | The duration of log phase. |
| | E) | The time it takes for nuclear division. |
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4 | |
An experiment began with 4 cells and ended with 128 cells. How many generations did the cells go through? |
| | A) | 64 |
| | B) | 32 |
| | C) | 6 |
| | D) | 5 |
| | E) | 4 |
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5 | |
If you start out with a population density of 200 CFU/ml of a bacterium that divides every 20 minutes, what will the population density be at the end of two hours, assuming the cells are in the log phase of growth. |
| | A) | 1200 CFU/ml |
| | B) | 26 CFU/ml |
| | C) | 3200 CFU/ml |
| | D) | 12800 CFU/ml |
| | E) | 2006 CFU/ml |
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Use this typical bacterial growth curve to answer the following question.
Compare the following entities (I and II).
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25 | |
I. average size of cells during the exponential phase of growth II. average size of cells during the lag phase of growth |
| | A) | I is greater than II, mark A |
| | B) | I is less than II, mark B |
| | C) | I is exactly or approximately equal to II, mark C |
| | D) | I may stand in more than one of the above relations to II, mark D |
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26 | |
I. generation time of cells during the exponential phase of growth II. generation time of cells during the lag phase of growth |
| | A) | I is greater than II, mark A |
| | B) | I is less than II, mark B |
| | C) | I is exactly or approximately equal to II, mark C |
| | D) | I may stand in more than one of the above relations to II, mark D |
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27 | |
I. generation time of a culture that produces 2 generations per hour II. generation time of a culture that produces 3 generations per hour |
| | A) | I is greater than II, mark A |
| | B) | I is less than II, mark B |
| | C) | I is exactly or approximately equal to II, mark C |
| | D) | I may stand in more than one of the above relations to II, mark D |
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28 | |
I. number of viable cells detected in a culture using an electronic counting devise II. number of viable cells detected in the same culture using a dilution and spread plating procedures |
| | A) | I is greater than II, mark A |
| | B) | I is less than II, mark B |
| | C) | I is exactly or approximately equal to II, mark C |
| | D) | I may stand in more than one of the above relations to II, mark D |
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29 | |
The total biomass of an organism will be determined by the nutrient present in the lowest concentration relative to the organism's requirements is a statement of |
| | A) | Liebig's Law of the minimum. |
| | B) | Shelford's law of tolerance. |
| | C) | the second law of thermodynamics. |
| | D) | quorum sensing. |
| | E) | Heisenberg's principle of uncertainty. |
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30 | |
The ability of Vibrio fischeri to produce bioluminescence chemicals only when a certain population density has been reached is an example of |
| | A) | Liebig's Law of the minimum. |
| | B) | Shelford's law of tolerance. |
| | C) | the second law of thermodynamics. |
| | D) | quorum sensing. |
| | E) | Heisenberg's principle of uncertainty. |
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2002 McGraw-Hill Higher Education