Flashcards in Chapter 6/13: Enumerating Microbes Deck (18):

0

## What type of microbe counting system uses a slide with an etched grid?

### Direct count

1

## What type of microbe counting system involves loading a known volume on a grid and counting under a light microscope?

### Direct count

2

## What type of microbe counting system involves diluting a culture in a series?

### Viable cell counting

3

## What type of microbe counting system measures colony-forming units (CFUs) per milliliter of initial culture?

### Viable cell counting

4

## What microbe counting system uses a filter apparatus if the cells are already very diluted?

### Viable cell counting

5

## What type of microbe counting system uses a spectrophotometer to give a rough measure of cell density in a tube?

### Turbidity

6

## Which phase in a microbial growth curve represents when microbes are gearing up for steady growth but not dividing?

### Lag phase

7

## Which phase in a microbial growth curve represents when microbes are replicating at a constant and steady exponential rate?

### Log phase

8

## Which phase in a microbial growth curve represents when replication has either halted due to lack of nutrients and excessive wastes, or the rate of replication is now equal to the death rate?

### Stationary phase

9

## Which phase in a microbial growth curve represents when nutrients are depleted and waste levels are high, or when cells are dying at a steady exponential rate?

### Death phase

10

## What term describes the time to double the population in the exponential phase?

### Generation (doubling) time

11

## What term describes the number of generations per unit of time?

### Growth rate

12

## What term describes the maximum population density and/or amount of cellular material produced by the culture?

### Growth yield

13

## Which three values can a microbial growth curve determine?

### Generation time, Growth rate, Growth yield

14

## What equation can be used to predict cell numbers in a population?

### Nt = No x 2^n

15

## What does No represent?

### Original population #

16

## What does Nt represent?

### # in population at time t

17