Block B

Question 1

The use of the Gram stain in microbiology is important because it differentiates…..

Answer 1

Bacterial cells with different types of cell walls

Question 2

In Gram’s stain, what colour are Gram-negative cells?

Answer 2

Pink

Question 3

Which taxon is NOT Gram–positive? A) Streptomyces B) Bacillus C) Pseudomonas D) Streptococcus E) Staphylococcus

Answer 3

Pseudomonas is Gram-negative

Question 4

Which feature(s) differentiate(s) Actinobacteria from Firmicutes?

Answer 4

relative G+C content intheir genomes

Question 5

Which bacterial genus is used for fermenting cabbage to make homemade sauerkraut?

Answer 5

Lactobacillus

Question 6

Staphylococcus aureus is known to cause ALL of the following diseases EXCEPT A) wound infection B) arthritis C) boils D) dental caries E) septicemia.

Answer 6

dental caries

Question 7

In comparison to bacteria that do have cell walls, ________ is a consequence of mycoplasmas lacking a cell wall.

Answer 7

FREQUENT EXISTANCE AS OBLIGATE SYMBIONTS

Question 8

A moistened swab rubbed onto a person’s forearm then onto a nutrient agar plate with 7.5% NaCl would MOST likely result in the isolation of ________ spp.

Answer 8

Staphylococcus

Question 9

Which organisms would MOST likely be isolated from aerobic growth conditions with acetate and a soil sample heated to 80°C for 10 min?

Answer 9

Endospore-forming bacteria

Question 10

Mycolic acids are exclusively present in Mycobacterium spp. and can be distinguished by a(n) ________ staining procedure and is a diagnostic utility to identify mycobacteria.

Answer 10

ACID FAST

Question 11

Which of the following is LEAST commonly associated with endospore–forming bacteria? A) coccus–shaped B) defense C) dormancy D) saprophytic E) heat–resistance

Answer 11

Coccus-shaped

Question 12

Streptomycin grow by

Answer 12

Polarized growth

Question 13

Which of the following bacterial genera are Gram positive? Escherichia, Acinetobacter, Pseudomonas, Streptococcus

Answer 13

Streptococcus

Question 14

Which bacterial genus lacks a cell wall? Mycoplasma, Mycobacteerium, Corynebacterium, Lactoccus

Answer 14

Mycoplasma

Question 15

Which of the following bacterial genera form spores? Streptomyces, Bacillus, Clostridium, Mycobacterium

Answer 15

Streptomyces, Bacillus, Clostridium

Question 16

Which type of protein is repsonsible for cell-entry of anthrax toxins?

Answer 16

primary antigen

Question 17

Which of the following bacterial genera are used for yoghurt production? Lactobacillus, Streptococcus, Staphylococcus, Lactococcus

Answer 17

Lactobacillus, Streptococcus, Lactococcus

Question 18

An example of a magneto tactic bacterium is…

Answer 18

Magnetospirillum

Question 19

Caulobacter crescentus is a model organism used to study…..

Answer 19

Cellular differentiation

Question 20

The genus Neisseria is associated with which two diseases?

Answer 20

Gonorrhoea and Meningitis

Question 21

Bordetella pertussis causes which disease?

Answer 21

Whooping cough

Question 22

Name the bacterium associated with the phrase ‘wolfpack’

Answer 22

Myxococcus xanthus (it is a social predator)

Question 23

The lipopolysaccharide (LPS) layer is found ONLY in the cell walls of

Answer 23

Gram-negative bacteria

Question 24

Which of the following organisms is Gram–negative? A) Mycobacterium tuberculosis B) Escherichia coli C) Bacillus subtilis D) Streptomyces coelicolor E) Clostridium difficile

Answer 24

B) Escherichia coli

Question 25

Although the inner leaflet of the Gram–negative outer membrane is composed mainly of phospholipids, the outer leaflet of the outer membrane also contains

Answer 25

lipopolysaccharides (LPS).

Question 26

In Gram–negative bacteria, the space between the membranes is called the:

Answer 26

Periplasm

Question 27

Which bacterial cell envelope component is made of N–acetylglucosamine and N–acetylmuramic acid?

Answer 27

Peptidoglycan

Question 28

polysaccharide can also be referred to as:

Answer 28

Endotoxin

Question 29

The inner-membrane of Gram-negative bacteria can also be referred to as the:

Answer 29

Cytoplasmic membrane

Question 30

Which component of the bacterial cell envelope is degraded by the enzyme lysozyme?

Answer 30

Peptidoglycan

Question 31

Give four examples of industrial/environment applications of bacteria

Answer 31

Antibiotic production, Enzyme production, Degradation of pesticides, Degradation of hydrocarbons

Question 32

Which of the following is not required to isolate a microorganism from the environment? A) A medium that is selective for the desired organism B) A medium that is de–selective for undesired organisms C) Growth temperature similar to the environment D) 37°C growth temperature E) 4°C growth temperature

Answer 32

E) 4°C growth temperature

Question 33

Which of the following are not used for the cultivation of aerobic bacteria? A) agar plates B) agar shake–tubes C) shake flasks D) microtiter dishes E) enrichment culture

Answer 33

B) agar shake-tubes

Question 34

Give four examples of typical properties of oligotrophic bacteria

Answer 34

1. Grow continuously 2. Grow slowly 3. Nutrient uptake enzymes with high affinity 4. Have Nutrient uptake enzymes with low specificity

Question 35

Give four examples of features of viable but non cultureable bacteria

Answer 35

Do not divide, Cannot grow on standard growth media, Morphologically smaller, Reduced nutrient transport / respiration / synthesis of macromolecules

Question 36

A soil sample was diluted into a nutrient broth, then spread onto a plate and grown for one week at room temperature. Several colonies appeared dusty or fuzzy and yet were identified as bacteria–not as fungi. Which genus do these isolates likely belong in?

Answer 36

Streptomyces

Question 37

Give four reasons why bacteria form biofilms

Answer 37

protection from predation, protection from antibiotics, allows occupancy of a favourable niche, allows cells to communicate / be close together

Question 38

What is the major disadvantage in enumeration bacteria by direct counting?

Answer 38

Cannot distinguish between live and dead bacteria

Question 39

Bioremediation of uranium depends on

Answer 39

metal–reducing bacteria

Question 40

What factors most likely limited the rate of petroleum degradation after the Exxon Valdez oil spill off the coast of Alaska?

Answer 40

temperature and inorganic nutrient concentrations

Question 41

Some benefits of growing in a microbial biofilm formation include….

Answer 41

niche occupancy, nutrient trapping, communication

Question 42

100 µl of a 10-7 dilution of a bacterial culture were plated onto an agar plate giving 46 colonies. What was the titre of the original culture?

Answer 42

4.6x10e9 cfu/ml

Question 43

Examples of bacterial genera that can degrade plastic include….

Answer 43

Alcaligenes, Pseudomonas, Bacillus

Question 44

Advantages of metagenomic analysis over 16S amplicon sequencing for bacteria community analysis include….

Answer 44

identification of all genes, discovery of new genes