(A)

Question 1

A (n) ___ is the total number of cases of a disease at any one time in a population
a. Prevalence
b. Morbidity
c. Mortality
d. Index
e. epidemic

Answer 1

a. Prevalence

Question 2

The lipopolysaccharide (LPS) that is found in the outer membrane of gram- negative
bacteria is also known as:
a. Exotoxin
b. Teichoic acid
c. Murein
d. Endotoxin
e. Peptidoglycan

Answer 2

d. Endotoxin

Question 3

Which of the following are characteristics used in taxonomic organization
a. Morphological
b. Physiological
c. Ecological
d. Two of the above
e. All of the above

Answer 3

e. All of the above
(a. Morphological
b. Physiological
c. Ecological)

Question 4

Proteins that are loosely attracted to the cytoplasmic membrane are called ___ proteins.
a. Peripheral
b. Integral
c. External
d. Internal
e. beta barrel

Answer 4

a. Peripheral

Question 5

Which of the following was the first to observe and accurately describe microorganisms?
a. Pasteur
b. Lister
c. Van leeuwenhoek
d. Tyndall
e. Koch

Answer 5

c. Van leeuwenhoek

Question 6

An epidemic is:
a. A disease that maintains a steady low level frequency
b. When a disease occurs occasionally and at erratic intervals in the human population
c. A sudden increase in the occurrence of a disease above the expected level
d. A sudden expected occurrence of a disease in a limited segment of a population
e. The total number of deaths in a population

Answer 6

c. A sudden increase in the occurrence of a disease above the expected level

Question 7

Who of the following developed a set of criteria that could be used to establish a
causative link between a particular microorganism and a particular disease?
a. Fracastoro
b. Koch
c. Pasteur
d. Lister
e. Van Leewenhoek

Answer 7

b. Koch

Question 8

Which of the following is not a criteria for the classical postulate of Robert Koch?
a. Microbes must be present in every case of disease and absent from healthy
individual
b. Must be able to grow the microbes in pure culture
c. Cultured microbes mist give the same disease state
d. Must be able to identify the virulence gene(s) responsible for the disease
e. Must be able to re-isolate microbes again from infected individuals

Answer 8

d. Must be able to identify the virulence gene(s) responsible for the disease

Question 9

Aerobic cells may enter stationary phase because:
a. Depletion of an essential nutrient
b. Lack of available oxygen
c. The accumulation of toxic waste products
d. Two of the above
e. All of the above

Answer 9

e. All of the above
(a. Depletion of an essential nutrient
b. Lack of available oxygen
c. The accumulation of toxic waste products)

Question 10

In a normal situation, the bacterium E. coli swims in a straight line, called a Run for a few seconds; then it stops, tumbles, then swim again in a new direction
a. True
b. False

Answer 10

a. True

Question 11

Chemotaxis implies that bacteria
a. Move toward an attractant
b. Move away from a repellent
c. Move toward an attractant and away from a repellent
d. Neither move toward an attractant nor away from a repellent

Answer 11

c. Move toward an attractant and away from a repellent

Question 12

The movement of molecules across a membrane from an area of higher concentration to an area of lower concentration carrier membrane embedded in the membrane is called:
a. Facilitated diffusion
b. Osmosis
c. Passive diffusion
d. Active transport

Answer 12

a. Facilitated diffusion

Question 13

Environment factors affecting growth of strict anaerobic bacteria can include but are not
limited to which of the following:
a. pH
b. Oxygen
c. Temperature
d. Two of the above
e. All of the above

Answer 13

e. All of the above
(a. pH
b. Oxygen
c. Temperature)

Question 14

If you have a tube filled with a solid media and after inoculation you observe uniform growth throughout the tube, then you most likely have an/a:
a. Obligate aerobe
b. Facultative anaerobe
c. Aerotolerant anaerobe
d. Strict anaerobe
e. Microaerophile

Answer 14

c. Aerotolerant anaerobe

Question 15

Given a log phase bacterial culture with 10e6 cells per ml and a generation time of 30 minutes, how long does it take the culture to reach a density of 6.4 x 10e7 cells per ml?
a. 1 hour
b. 2 hours
c. 3 hours
d. 4 hours
e. 5 hours

Answer 15

c. 3 hours

(6.4 x 10^7)/10^6 = 64 = 2^x
2^6 = 2^x
x = 6 generations
6 gen x 30 min per gen = 180 min = 3 hr

Question 16

Microorganisms generally maintain the fluidity of the mosaic membrane by
a. Increasing the level of cis unsaturated fatty acid in the membrane at low
temperature
b. Increasing the level of saturated fatty acid in the membrane at high temperature
c. Increasing the number of fatty acid molecules on the phospholipid at high
temperature
d. Two of the above (a & b)
e. All of the above

Answer 16

d. Two of the above (a & b)

low temp = very solid = incr unsaturated to make fluid
high temp = very fluid = incr saturated to make solid

Question 17

You find a microorganism has optimum growth at pH 9.5 and a temperature of 10 C, this organism is a:
a. Neutrophilic mesophile
b. Acidophilic thermophile
c. Alkalophilic mesophile
d. Neutrophilic psychrophile
e. Alkalophilic psychrophile

Answer 17

e. Alkalophilic psychrophile

9.5 pH is basic (alkaline), 10 C is psycho (cold)

Question 18

Nutrients can be concentrated inside the cell from a diluted extracellular environment by:
a. facilitated diffusion
b. Active transport
c. Group translocation phosphotransferase system (PTS system)
d. Active transport and group translocation
e. facilitated diffusion and group translocation

Answer 18

d. Active transport and group translocation

b/c going from a low to high concentration

Question 19

E.coli doubles every minute every 20 minutes at optimal growth. Within the first 5
minutes after you add 10 microliters of a dense E. coli culture grown in minimal media into a flask containing 100 ml of a rich media, you can assume these bacteria are in:
a. Sporulation phase
b. Log phase
c. Stationary phase
d. Death phase
e. Lag phase

Answer 19

e. Lag phase

Question 20

You want to measure the O.D. (optical density) of a dense E.coli culture grown overnight using a spectrophotometer to estimate cell numbers. You can expect to see:
a. Low transmittance
b. Low OD
c. High OD
d. A and B are correct
e. A and C are correct

Answer 20

e. A and C are correct

(a. Low transmittance
c. High OD)
cells are increasing

Question 21

Gram-positive bacteria have thick cell wall, lack outer membrane, and have a
periplasmic-like space
a. True
b. False

Answer 21

a. True

Question 22

Select the correct answer below according to definition of bacterial flagella/flagellum that
is rod shape:
a. Monotrichous- a single flagellum at each pole of an organism
b. Peritrichous- a relatively even distribution of flagella around the rod shaped
bacterium
c. Lophotrichous - a single flagellum
d. Amphitrichous - a cluster of flagella at one or both ends of a rod shape bacterium
e. None of the above are correct

Answer 22

b. Peritrichous- a relatively even distribution of flagella around the rod shaped
bacterium

Question 23

Transport of two different substances across biomembranes can be linked. If the transport is in the same direction it is called symport. If the transport is in opposite
directions it is called antiport
a. True
b. False

Answer 23

a. True

Question 24

LPS of Gram-negative are phospholipid molecules containing glycerol
a. True
b. False

Answer 24

b. False

Question 25

Which of the following are true about the inner membrane of bacteria? a. Has the outer leaflet made of LPS b. Has no proton motive force across this membrane c. Contains porins (membrane proteins) made of beta-barrels d. Two of the above are true e. None of the above are true

Answer 25

e. None of the above are true

Question 26

Which of the following is an incorrect way of representing a particular microorganism with the binomial system of nomenclature? a. Escherichia coli b. E.coli c. Esch. Coli d. All of the above are correct and acceptable e. None of the above are correct and acceptable

Answer 26

c. Esch. Coli

Question 27

Type II secretion system in bacteria: a. Exists mostly in Gram-positives and less so in Gram-negatives b. Export protein first to the periplasmic space in Gram-negatives c. Utilizes the general secretory pathway (sec-pathway) d. Acts like a needle and syringe to inject proteins directly into target cells e. None of the above

Answer 27

c. Utilizes the general secretory pathway (sec-pathway)

Question 28

Generation times can vary markedly depending on a. The species of a microorganism b. The environmental conditions c. Both A and B are correct d. Neither A nor B is correct

Answer 28

c. Both A and B are correct (a. The species of a microorganism b. The environmental conditions)

Question 29

In lecture, when or why is there a need for GasPak and Palladium pellets? a. To create O2 important for aerobic microbes to grow b. To create CO2 important for aerobic microbes to grow c. To create H2 important for aerobic microbes to grow d. To create H20 important for aerobic microbes to grow e. None of the above are correct

Answer 29

e. None of the above are correct GasPack gives CO2, Palladium pellets convert H2 + O2 = H2O both used to make anaerobic (no O2) conditions

Question 30

A chemolithoautotroph uses what with respect to carbon, electron and energy source? a. Light energy, organic H/e- donor, and CO2 as carbon source b. Chemical energy, inorganic H/e- donor, and CO2 as carbon source c. Light energy, inorganic H/e- donor, and organic carbon source d. Chemical energy, organic H/e- donor, and CO2 as carbon source e. None of the above are correct

Answer 30

b. Chemical energy, inorganic H/e- donor, and CO2 as carbon source

Question 31

During peptidoglycan (cell wall biosynthesis) of bacteria, what sugar is the pentapeptide linked to? a. N-acetyl muramic acid b. N-acetyl glucosamine c. Bactoprenol d. Diaminopimelic acid (DAP) e. Lysine

Answer 31

a. N-acetyl muramic acid

Question 32

Which of the following is directly involved in Gram-negative peptidoglycan cross-linking? a. Diminopimellic acid (DAP) b. Lysine c. Pentaglycine d. L-alanine e. None of the above are correct

Answer 32

a. Diminopimellic acid (DAP)

Question 33

A biofilm, smaller than a capsule, is a polysaccharide layer that is produced immediately at the surface of bacteria that protect them from desiccation a. True b. False

Answer 33

b. False

Question 34

Respectively, the amino acids side chains of Trp and Ile at neutral pH are: a. Trp uncharged aromatic and Ile is non-polar hydrophobic b. Trp is charged aromatic and Ile is polar positive c. Trp is charged polar and Ile is non-polar hydrophobic d. Trp is charged non-polar and Ile is charged hydrophobic e. None of the above

Answer 34

a. Trp uncharged aromatic and Ile is non-polar hydrophobic

Question 35

In a beta-strand not alpha-helix), how are amino acid side-chains for polypeptide oriented relative to each other? a. All amino acid side-chains point in the same direction b. Alternating amino acids side-chains point in opposite direction c. All amino acid side chains point in opposite direction d. All amino acid side-chains point in random direction e. None of the above

Answer 35

b. Alternating amino acids side-chains point in opposite direction

Question 36

In Valine, Aspartic acid, and lysine form a three amino acid peptide chain, what is the total positive, total negative, and net charge of this molecule at pH = 77? a. Total + 2, total -2, and net charge of zero b. Total +1, total -1, and net charge of zero c. Total +2, total -1, and net charge of +1 d. Total +1, total -2, and net charge of -1

Answer 36

a. Total + 2, total -2, and net charge of zero N - V - D - L - C (+) - (0) - (-) - (+) - (-) net = 0

Question 37

In a nucleotide (e.g. ATP) the glycosidic bond of the five carbon-containing ribose sugar involves the: a. #1 carbon b. #2 carbon c. #3 carbon d. #4 carbon e. #5 carbon

Answer 37

a. #1 carbon (I'd add a pic but that cost $$, just google "ATP structure". Carbons count 1-5 starting on the right of the O in the ring and ending on the left "arm". #1 carbon is connected to the N group)

Question 38

In a nucleotide (e.g. GTP) the chiral center of the five carbon-containing ribose sugar is at the: a. 1 carbon b. 2 carbons c. 3 carbons d. 4 carbons e. 5 carbons

Answer 38

d. 4 carbons (I'd add a pic but that cost $$, just google "GTP structure". Carbons count 1-5 starting on the right of the O in the ring and ending on the left "arm". #4 carbon is on the ring, connected to the left "arm" group and the O in the ring)

Question 39

In most biomolecules of living cells, amino acids and sugars exist as: a. L-amino acids and D-sugars b. D-amino acids and D-sugars c. L-amino acids and L-sugars d. D-amino acids and L-sugars

Answer 39

a. L-amino acids and D-sugars

Question 40

Generally, bacterial mitochondria are much smaller than a mitochondria of eukaryotic cells a. True b. False

Answer 40

b. False