Midterms_Microbial Growth

Question 1

Most frequently used method of measuring bacterial populations.

Answer 1

Plate count

Question 2

Use a __________ to determine % transmission or absorbance.

Answer 2

Spectrophotometer

Question 3

Cells division begins to slow down

Answer 3

Stationary phase

Question 4

Period of most rapid growth. Number of cells produced > Number of cell dying

Answer 4

Log phase

Question 5

Factors that slow down microbial growth

Answer 5

(AALI): Accumulation of toxic waste materials, acidic pH of media, limited nutrients, insufficient oxygen supply

Question 6

As bacteria multiply in media, it becomes ____.

Answer 6

Turbidity

Question 7

One advantage is that colonies will be on surface and not exposed to melted agar

Answer 7

Spread plate

Question 8

Used mainly to measure bacteria that will not grow on solid medium

Answer 8

Most Probable Number (MPN)

Question 9

Cells are at highest metabolic activity

Answer 9

Log phase

Question 10

Used to measure small quantities of bacteria

Answer 10

Filtration

Question 11

Not useful for heat sensitive organisms and colonies appear under agar surface

Answer 11

Pour Plate

Question 12

Stain is added to visualize bacteria

Answer 12

Direct Microscopic Count

Question 13

Cell number decrease at a logarithmic rate

Answer 13

Death phase

Question 14

Bacteria grow and divide by ________, a rapid and relatively simple process.

Answer 14

Binary fission

Question 15

May last from one hour to several days

Answer 15

Lag phase

Question 16

Cells lose their ability to divide

Answer 16

Death phase

Question 17

Cells are most susceptible to adverse environmental factors at this stage

Answer 17

Log phase

Question 18

Period of adjustment to new conditions

Answer 18

Lag phase

Question 19

Overall cell number does not increase

Answer 19

Stationary phase

Question 20

Population size begins to decrease. Number of cells dying&raquo_space;> number of cell produced

Answer 20

Death phase

Question 21

Growth Cycle (4)

Answer 21

Lag phase, Log Phase, Stationary Phase, Death/Decline Phase

Question 22

Phase of intense metabolic activity, in which individual organisms grow in size

Answer 22

Lag phase

Question 23

Require a high concentration of bacteria

Answer 23

Direct Microscopic Count

Question 24

Population size begins to stabilize. Number of cell produced=Number of cells dying

Answer 24

Stationary phase

Question 25

Refers to an increase in cell number, not in cell size.

Answer 25

Microbial Growth

Question 26

Little or no cell division occurs, population size doesn’t increase

Answer 26

Lag phase

Question 27

Cells begin to divide and generation time reaches a constant minimum.

Answer 27

Log phase

Question 28

A few cells may remain alive for a long period of time

Answer 28

Death phase