Lecture 6

Question 1

science of classification of organisms

Answer 1

Taxonomy

Question 2

refers to the actual naming of organisms

Answer 2

Nomenclature

Question 3

a group of related species

Answer 3

Genus

Question 4

organisms that are substantially alike

Answer 4

Species

Question 5

Proper names of organisms are always ____________
The genus is _______________

Answer 5

italicized, capitalized

Question 6

The typical diameter of the cell ranges from ___________

Answer 6

0.5 to 1 µm

Question 7

Bacteria reproduce predominantly by a process known as

Answer 7

binary fission

Question 8

Sources of energy

Answer 8

Phototrophs
Chemotrophs

Question 9

organisms which are capable of employing radiant energy.

Answer 9

Phototrophs

Question 10

organisms which obtain the energy for their activities and self-synthesis from chemical reactions that can occur in the dark

Answer 10

Chemotrophs

Question 11

Sources of carbon

Answer 11

autotrophs
heterotrophs

Question 12

organisms which can thrive on an entirely inorganic diet, using CO2 or carbonates as a sole source of carbon.

Answer 12

autotrophs

Question 13

organisms which cannot use CO2 as a sole source of carbon but require, in addition to minerals, one or more organic substances, such as glucose or amino acids, as sources of carbon

Answer 13

heterotroph

Question 14

Sources of nitrogen

Answer 14

atmospheric nitrogen, inorganic nitrogen compounds, or other derived nitrogen.

Question 15

Temperature range for growth (Psychrophiles)

Answer 15

-7~35C

Question 16

Temperature range for growth (Mesophiles)

Answer 16

7~45C

Question 17

Temperature range for growth (Thermophiles)

Answer 17

40~75C

Question 18

bacteria grow in the presence of free oxygen

Answer 18

Aerobic

Question 19

bacteria grow in the absence of free
oxygen

Answer 19

Anaerobic

Question 20

bacteria grow in either the
absence or the presence of free oxygen

Answer 20

Facultatively anaerobic

Question 21

bacteria grow in the presence of
minute quantities of free oxygen.

Answer 21

Microaerophilic

Question 22

For most bacteria the optimum pH for growth lies between

Answer 22

6.5 and 7.5

Question 23

For most species the minimum and maximum limits fall somewhere between

Answer 23

pH 4 and pH 9

Question 24

pH for different bacteria
Bacteria ______
Yeast ______
Molds ______
Plant cells _____
Animal cells _______

Answer 24

3-8
3-6
3-7
5-6
6.5-7.5

Question 25

Only a few species can grow at pH values of less than 2 or greater than 10

Answer 25

Acidophiles Alkaliphiles

Question 26

tend to be more tolerant to acids than bacteria

Answer 26

fungus

Question 26

optimal pH at 10-11

Answer 26

Alkaliphiles

Question 27

___________ tend to be more tolerant to acids than bacteria.

Answer 27

Fungus

Question 28

The internal pH of the cell must remain close to __________to prevent the destruction of the cell.

Answer 28

neutral

Question 29

The pH of the medium changes during most __________

Answer 29

fermentations

Question 30

pH is mostly controlled by the use of an effective _________

Answer 30

buffer system

Question 31

Some bacteria form spores when growth ceases due to _________ or other causes.

Answer 31

starvation

Question 32

are plants devoid of chlorophyll and are therefore unable to synthesize their own food

Answer 32

fungi

Question 33

are more resistant than normal cells to heat, drying, radiation, and chemicals.

Answer 33

Spores

Question 34

are found most commonly in the soil.

Answer 34

Spore-forming bacteria

Question 35

_________are plants devoid of chlorophyll and are therefore unable to synthesize their own food.

Answer 35

Fungi

Question 36

The growth of microbial population in artificial environments is called

Answer 36

cultivation

Question 37

A culture that contains only one kind of microorganism is a

Answer 37

pure culture

Question 38

is one that contains more than one kind of microorganism.

Answer 38

mixed culture

Question 39

Media types

Answer 39

Natural Synthetic

Question 40

 Used on the basis of experience and not on of exact knowledge of their composition and action.  Usually contain peptones, beef extract, or yeast extract.

Answer 40

Natural media

Question 41

 Consist of dilute, reproducible solutions of chemically pure, known inorganic and/or organic compounds.  They are often required for research purposes.

Answer 41

Synthetic Media

Question 42

After a suitable culture medium is selected for the cultivation of a specific microorganism, it is poured into a .

Answer 42

culture vessel

Question 43

The most common method of sterilization is by moist heat (steam under pressure) in _______

Answer 43

an autoclave

Question 44

The growth of microbial population in artificial environments is called

Answer 44

cultivation

Question 45

A culture that contains only one kind of microorganism is a

Answer 45

pure culture

Question 46

is one that contains more than one kind of microorganism.

Answer 46

mixed culture

Question 47

steps for cultivation

Answer 47

 Preparing a culture medium in which a microorganism can grow best.  Sterilizing in order to eliminate all living organisms in the vessel.  Inoculating the microorganism in the prepared medium.  Culture media are usually prepared in a test tube, a flask, a Petri dish, or a fermenter.

Question 48

Generally, the autoclave is operated at approximately

Answer 48

15 psi at 121°C.

Question 49

The time of sterilization depends on

Answer 49

the nature of the material, the type of container, and the volume.

Question 50

is the seeding of a culture vessel with the microbial material

Answer 50

inoculation

Question 51

is the seeding of a culture vessel with the microbial material (inoculum)

Answer 51

Inoculation

Question 52

The _________ is introduced with a metal wire or loop which is rapidly sterilized just before its use by heating it in a flame.

Answer 52

inoculum

Question 53

Transfers of liquid culture are often made by using a __________

Answer 53

sterilized pipette

Question 54

The inoculation is usually done in a __________to minimize the risk of contamination.

Answer 54

laminar flow hood

Question 55

is a period of adaptation of cell to a new environment.

Answer 55

Lag phase

Question 56

Nutrients low in certain growth factors may lead to

Answer 56

long lag phases.

Question 57

The lag phase is also dependent on the age of the __________

Answer 57

inoculum

Question 58

Lag phase ____________ with age of inoculum

Answer 58

increases

Question 59

________ are best to minimize lag phase

Answer 59

Exponential phase cells

Question 60

Also the use of large inoculum size ___________ the duration of lag phase.

Answer 60

Decreases

Question 61

is a period of adaptation of cell to a new environment

Answer 61

Lag phase

Question 62

Multiple lag phases may be observed when the medium contains more than one carbon source

Answer 62

diauxic growth

Question 63

Cell mass and density increase exponentially because the cell is now fully developed to its environment

Answer 63

Exponential growth phase

Question 64

Composition of a single cell remains approximately constant during _____________

Answer 64

exponential growth phase.

Question 65

Growth _________ due to the depletion of one or more essential nutrients or the accumulation of toxic byproducts

Answer 65

decelerates

Question 66

Net growth rate is zero. Growth rate =

Answer 66

Death rate

Question 67

A second growth phase may occur and cells may grow on lysis product of lysed cells

Answer 67

cryptic growth

Question 68

During stationary phase, the cell catabolizes cellular reserves for new building blocks and for energy producing monomers.

Answer 68

Endogenous metabolism

Question 69

are defined based on the actual consumption of material.

Answer 69

Yield coefficients

Question 70

At high temperature, the thermal death rate _______ the growth rate.

Answer 70

exceeds