ICA Questions

Question 1

Which statement about glycolysis is correct?
- Two net molecules of ATP are produced through substrate-level phosphorylation
- A proton gradient is established across the mitochondrial membrane
- Three molecules of NADH2 and one molecule of FADH2 are produced
- Glycolysis cannot proceed under anaerobic conditions

Answer 1

Two net molecules of ATP are produced through substrate level phosphorylation

Question 2

Which of the following is NOT true of glycolysis?
- It produces 4 net ATP
- It requires an input of ATP to begin
- It occurs in the cytoplasm
- It produces NADH

Answer 2

It produces 4 net ATP

Question 3

C. perfrings is an obligate anaerobic bacterium unable to survive in the presence of oxygen.

Which of the following enzymes will NOT be found in C. perfrings that you would normally find in an aerobic bacteria?

Answer 3

Superoxide dismutase and Peroxidase

Question 4

Which of the following is NOT correct with respect to the redox pair NAD+/NADH?
- NADH can accept electrons from an electron transport system
- The reduced, nonaromatic ring of NADH is at a higher energy than the aromatic ring of NAD+
- The nicotinamide ring is heteroaromatic because it has a noncarbon atom is the 4th position
- The nicotinamide ring is a relatively stable aromatic structure

Answer 4

NADH can accept electrons from an electron transport system

Question 5

You feed E. coli 3 glucose molecules. How many ATP are created ONLY using glycolysis?

Answer 5

6

Question 6

Fermentation can be defined as?

Answer 6

Partial breakdown of organic food without the use of an electron transport system

Question 7

Which of the following fermentation processes is responsible for making bread?

Answer 7

Ethanolic fermentation

Question 8

Which is not an end product of fermentation?

Answer 8

Pyruvate

Question 9

Microorganisms play an active role in the formation different kinds of products from fermentation. Which one of the following is mismatched?
- Ethanolic fermentation – ethanol and CO2
- Homolactic fermentation – lactic acid and CO2
- Heterolactic fermentation – lactic acid, ethanol and CO2
- Mixed acid fermentation - multiple acids and H2 and CO2

Answer 9

Homolactic fermentation - lactic acid and CO2

Question 10

Fermentation produces more energy than anaerobic respiration.

Answer 10

FALSE

Question 11

Methyl red positive tube contains more acids than a phenol red positive tube.

Answer 11

TRUE

Question 12

The TCA cycle is capable of generating which of the following products from oxidation of each acetyl-CoA molecule

Answer 12

2 carbon dioxide molecules, 3 NADH, 1 FADH2, and 1 ATP

Question 13

How many electron carriers in total are created from just the TCA from 2 glucose molecules?

Answer 13

16

Question 14

You feed E. coli 3 glucose molecules. How many ATP are created ONLY through substrate level phosphorylation?

Answer 14

12

Question 15

Cells can catabolize acetate or fatty acids using a modified TCA called glyoxylate shunt shown below.
Which of the following is NOT TRUE about glyoxylate shunt?
- It produces less CO2 than a TCA
- It produces more NADH than TCA
- It gets activated when glucose is absent or in less amount
- It produces less NADH than a TCA

Answer 15

It produces more NADH than TCA

Question 16

An unknown bacterium can be tested for fermentation of lactose to mixed acid byproducts such as malic acid and succinic acid through which of the following tests?

Answer 16

Methyl Red test

Question 17

Rank according to ATP yield, from high to low.
1. Fermentation
2. Aerobic respiration
3. Anaerobic respiration

Answer 17

2,3,1

Question 18

Which of the following statements about anaerobic respiration is FALSE?
- It yields equal amounts of ATP when compared to aerobic respiration
- It yields lower amounts of ATP when compared to aerobic respiration.
- The complete Krebs cycle is utilized
- It does not involve the ETS

Answer 18

It yields equal amounts of ATP when compared to aerobic respiration

Question 19

E. coli ETS includes which of the following components.

Answer 19

NADH oxidoreductase, Terminal Oxidase, and Mobile electron carrier

Question 20

E. coli produces __________ ATP by substrate level phosphorylation and ___________ ATP from oxidative phosphorylation from 1 glucose.

Answer 20

4, 34

Question 21

Which of the following is NOT true about mitochondrial ETS.
- Mitochondrial ETS pumps 12 H+ per NADH, 2 more than E. coli
- Mitochondrial ETS can produce ATP with out the use of ATP synthase
- Possess an intermediate cytochrome oxidase complex
- Mitochondrial ETS is capable of producing more proton motive force when compared with E. coli ETS per every glucose molecule

Answer 21

Mitochondrial ETS can produce ATP with out the use of ATP synthase

Question 22

You encounter a previously unknown organism in a sample of seawater. Observing this organism under the microscope, you observe the following:

An intricate internal membrane system
Linear chromosomes
DNA sequence reveals that its genome is made of 4 types of nucleotides (A, T, C and G).
DNA sequence reveals that much of the genome of this organism does not code for protein.
What kind of organism is this?

Answer 22

Eukaryote

Question 23

You encounter a previously unknown organism in a sample of seawater. Observing this organism under the microscope, you observe the following:

An intricate internal membrane system
Linear chromosomes
DNA sequence reveals that its genome is made of 4 types of nucleotides (A, T, C and G).
DNA sequence reveals that most of the genome of this organism does not code for protein.
Based on your answer to the previous question? How did you determine the type of organism?

Answer 23

Presence of internal membrane systems, most of the genome of this organism does not code for protein, and linear chromosomes

Question 24

Now imagine that you have isolated a genomic sequence of an unknown organism from seawater but do not have any cells that you are able to observe or culture. The genome exists as two separate pieces of DNA that have their genes placed in functional groups and have relatively little intergenic (non-coding) DNA.

What kind of organism is this?

Answer 24

Bacterium, Archaeon, or Prokaryote

Question 25

Now imagine that you have isolated a genomic sequence of an unknown organism from seawater but do not have any cells that you are able to observe or culture. The genome exists as two separate pieces of DNA that have their genes placed in functional groups and have relatively little intergenic (non-coding) DNA. You discover that the smaller of the two pieces of DNA contains several genes involved in the hydrolysis (metabolism) of glucose. Is this more likely to be a plasmid or a chromosome or both?

Answer 25

Chromosome

Question 26

Now imagine that you have isolated a genomic sequence of an unknown organism from seawater but do not have any cells that you are able to observe or culture. The genome exists as two separate pieces of DNA that have their genes placed in functional groups and have relatively little intergenic (non-coding) DNA. You discover that the smaller of the two pieces of DNA contains several genes involved in the hydrolysis (metabolism) of glucose. How do you know if is it a plasmid or a chromosome or both?

Answer 26

It contains genes involved in the metabolism of glucose which are essential to the cell

Question 27

Which of the following will be observed in a bacterium that lost its ability to make DNA ligase.

Answer 27

You will find many small fragments of DNA in the cytoplasm of the bacterium

Question 28

Which of these represents a correct order of proteins involved in bacterial DNA replication?

Answer 28

DnaA → primase → DNA pol III → ligase

Question 29

Which of the following is NOT true when it comes to Bacterial DNA Replication. - Replication in bacteria begins only from one location in the chromosome - Replication is bidirectional - It is semiconservative - It requires only one set of DNA polymerase

Answer 29

It requires only one set of DNA polymerase

Question 30

You isolate a piece of DNA from a microorganism you cultivated from your teeth. The piece of DNA is 94 kbp in size and is circular. You sequence it and discover that it contains genes for pili, and antibiotic resistance. What is this piece of DNA?

Answer 30

plasmid

Question 31

All of the following are required in a PCR reaction EXCEPT - DNA template - DNA polymerase - DNA ligase - Primers

Answer 31

DNA ligase

Question 32

Which of the following is/are TRUE about PCR. - It requires DNA polymerase - It requires heating - It required DNA ligase - It requires DNA primers - It involves Okazaki fragments

Answer 32

It requires DNA polymerase, heating, and DNA primers

Question 33

The necessary ingredients for PCR reactions are mixed together in a test tube. The DNA polymerase is from Thermus aquaticus, and the DNA template is from an E. coli. The newly synthesized DNA would look like _____.

Answer 33

E. coli DNA

Question 34

Taq DNA Polymerase is commonly used in Polymerase Chain Reaction (PCR) because:

Answer 34

It functions in high temperature environments

Question 35

You are a public health official investigating an outbreak of Salmonella. To detect current cases you choose to examine patients blood for the ____________ antibody class.

Answer 35

IgM

Question 36

In adaptive immunity, the term “clonal selection” best refers to the

Answer 36

ability of specific B-cell subsets to proliferate and produce antibodies upon exposure to a specific epitope.

Question 37

Which of the following statements about MHC class II molecules are true? - They are found only on antigen presenting cells - They present extracellular antigens. - They are found on all nucleated cells. - They are found on the surface of most pathogens

Answer 37

They are found only on antigen presenting cells and present extracellular antigens

Question 38

An immune deficiency causes a severe reduction in the amount of MHC-II expressed on the surface of professional antigen-presenting cells. Predict which immune processes will be significantly impacted by this deficiency.

Answer 38

Phagocytosis by macrophages, antibody production, and cell killing by cytotoxic T cells

Question 39

Which of the following can be used to make vaccines?

Answer 39

Purified components of microorganisms, Killed microorganisms, Live microorganisms, and mRNA that codes for an antigen

Question 40

Innate immunity involves all of the following host defenses EXCEPT - production of antibodies to bind specific pathogen proteins. - production of small peptides that destroy the bacterial membrane. - engulfment of microbes by phagocytes. - secretion of mucus to prevent microbial entry.

Answer 40

production of antibodies to bind specific pathogen proteins

Question 41

Opsonization is a process whereby innate and adaptive immunity work together to

Answer 41

phagocytize an invader

Question 42

Which body sites are colonized by normal microbiota? - Lungs - Kidneys - Small Intestine - Stomach - Urinary bladder

Answer 42

Lungs, small intestine, stomach, and urinary bladder

Question 43

Under what circumstances can microbiota cause disease?

Answer 43

- If other normal flora microbes are reduced or eliminated, as with antibiotic treatment - Can cause disease when they accidentally penetrate beyond their normal flora sites

Question 44

How do the lungs avoid being colonized by pathogens?

Answer 44

- The lungs are also protected by alveolar macrophages that ingest and kill pathogens that make it past the ciliary elevator. - By using a mechanism called the mucociliary escalator to avoid being colonized

Question 45

A man has been taking excessive amounts of antacids for heartburn. Which innate defense mechanism might be altered by his actions?

Answer 45

increase in the pH of stomach acid and exposes himself to more GI tract infection

Question 46

Match Type III Secretion system with the organism that utilize for their pathogenesis

Answer 46

Salmonella species

Question 47

Match Type IV Secretion system with the organism that utilize for their pathogenesis

Answer 47

Bordetella pertussis

Question 48

Thick polysaccharide capsules are important virulence assets for which of the following species?

Answer 48

Neisseria meningitidis and Sptreptococcus pneumonia

Question 49

Streptococcus pyogenes virulence factors

Answer 49

M protein

Question 50

Staphylococcus aureus virulence factors

Answer 50

Alpha toxin, Toxic shock syndrome toxin, Exfoliant toxins A & B, and Protein A

Question 51

E. coli O157:H7 virulence factors

Answer 51

Shiga-like toxin

Question 52

Streptococcus pneumoniae virulence factors

Answer 52

Capsule

Question 53

Mycobacterium tuberculosis virulence factors

Answer 53

Multi drug resistance

Question 54

S. aureus disease

Answer 54

Scalded skin syndrome

Question 55

Y. pestis disease

Answer 55

Bubonic plague

Question 56

P. falciparum disease

Answer 56

Cerebral malaria

Question 57

T. palladium disease

Answer 57

syphilis

Question 58

S. pyogenes disease

Answer 58

Necrotizing fasciitis

Question 59

All of the following are good indications of a pathogenicity island in a microbial chromosome EXCEPT - GC/AT ratio higher or lower than the rest of the chromosome. - presence of clusters of virulence genes - residual phage genomes flank the island. - presence of RNA nucleotides

Answer 59

Presence of RNA nucleotides

Question 60

The alpha toxin of Staphylococcus aureus have similar effect on human cells as the antibiotic _______ on gram negative bacteria.

Answer 60

Gramicidin

Question 61

Based on your knowledge of microbial genetics and microbial pathogenesis, where do you think the genetic information for endotoxins are located?

Answer 61

Chromosomes

Question 62

Based on your knowledge of microbial genetics and microbial pathogenesis, where do you think is/are the likely location/s of the genetic information for E. coil shiga exotoxins?

Answer 62

Plasmids, chromosomes, and phage genome

Question 63

Consider an MIC result of 5 μg/ml of penicillin for bacterial strain A, 25 μg/ml for strain B, 15 μg/ml for strain C, and 20 μg/ml for strain D. Which bacterial strain can be interpreted as the most resistant to penicillin?

Answer 63

B

Question 64

Consider a mutation in which the change is from UAC to UAG. Which type of mutation is this?

Answer 64

Nonsense mutation

Question 65

You inoculated 100 bacteria A, with a generation time of 20 minutes, into 100 ml of nutrient broth. At the same time, you inoculated 100 bacteria B with generation time of 20 minutes into 200 ml of nutrient broth. After incubation for 24 hours, if all cells divide by binary fission and remain viable in log phase, you can reasonably expect to have

Answer 65

The same number of cells in both cultures

Question 66

You inoculated 100 bacteria A, with a generation time of 20 minutes, into 100 ml of nutrient broth. At the same time, you inoculated 200 bacteria B with generation time of 20 minutes into 200 ml of nutrient broth. After incubation for 24 hours, if all cells divide by binary fission and remain viable in log phase, you can reasonably expect to have

Answer 66

More bacteria B in the 200mL

Question 67

C. botulinum is an aerotolerant anaerobic bacterium able to survive in the presence of oxygen with the help of certain metabolic antioxidants. Which of the following enzymes would you expect to find in C. botulinum that you would not find in a strict anaerobe?

Answer 67

superoxide dismutase

Question 68

Serial dilutions can be used to estimate the total number of ONLY living bacteria not dead bacteria.

Answer 68

TRUE

Question 69

One cell with generation times of 60 minutes are inoculated into a culture medium. How many cells are there after 5 hours?

Answer 69

32

Question 70

2 bacterial cells with generation time of 20 minutes are inoculated into a culture medium. How many cells are there after 2 hours? (Assuming all cells divide by binary fission in log phase and remained viable).

Answer 70

128

Question 71

A virus such as influenza virus might produce 800 progeny virus particles from one host cell infected by one virus. How would you mathematically represent the exponential growth of the virus?

Answer 71

800^n

Question 72

A cafeteria worker who fails to wash his hands thoroughly and fails to wear gloves inoculates a pie with 4 E.coli cells in when he uses his finger to test whether it is done. By the time you purchase the pie, there were 128 E.coli cells. How many generations did the cells go through between the initial inoculation and the time you bought the pie? Assuming all cells multiplied in a log phase.

Answer 72

5

Question 73

A cafeteria worker who fails to wash his hands thoroughly and fails to wear gloves inoculates a pie with 4 E.coli cells in when he uses his finger to test whether it is done. By the time you purchase the pie, there were 128 E.coli cells. How many minutes it took from the time he touched it until you purchased it? Assuming all cells multiplied in a log phase. FYI, E. coli have a generation time of 20 minutes.

Answer 73

100

Question 74

The a part of the lipopolysaccharide (LPS) that is found in the outer membrane of Gram-negative bacteria is also known as _________.

Answer 74

endotoxin

Question 75

After you run a couple of experiments, you got the following results. Cell wall = Contains peptidoglycan Cell membrane type = lipid bilayer Fatty acid linkage = ester bonds Cell envelope = contain mycolic acids What are organism A?

Answer 75

Mycobacterium species

Question 76

Which arrangement is commonly seen in organisms in the Genus Staphylococcus?

Answer 76

clusters

Question 77

Student in the lab performs a Gram stain on Staphylococcus aureus, a Gram positive cocci. The student skips the decolorizing step. When the student observes the slide under 100x magnification what do they see? Assume all other steps were followed properly

Answer 77

Gram positive cocci

Question 78

A student in the lab performs a Gram stain on E. coli, a Gram negative bacilli. The student skips the decolorizing step. When the student observes the slide under 100x magnification what does the student see at the end of the experiment? Assume all other steps are followed properly.

Answer 78

Gram positive bacilli

Question 79

Bacteria and archaea are different in all of the following EXCEPT - Size and shape - Cell wall composition - rRNA sequence - Cell membrane composition

Answer 79

Size and shape

Question 80

What is true regarding proteins that are embedded within the cell membrane?

Answer 80

They provide structural support

Question 81

What are two commonalities between Gram negative and Gram positive cell envelop?

Answer 81

Peptidoglycan and Cell membrane

Question 82

Calculate the total magnification of the microscope you use in your microbiology lab when using 20X objective lens.

Answer 82

200

Question 83

Calculate the numerical aperture (NA) of the objective lens shown below if the medium between the objective and sample if air. Theta = 15 degrees

Answer 83

0.26

Question 84

An objective lens with a magnification of 40X created an angle of cone of light measured from the center of 30o (see below). Calculate refractive index (n) of the medium between the tip of the objective and the sample if the NA is 0.67?

Answer 84

1.34

Question 85

An objective lens with a magnification of 40X created an angle of cone of light measured from the center of 30o (see below). Name the medium between the tip of the objective and the sample if you calculated the NA to be 0.67 with the given setup above?

Answer 85

Water

Question 86

If 0.2 μm = 200 nm, 150 μm = ______ nm

Answer 86

150,000 nm

Question 87

Sari is a microbiology student attempting to identify a microbe that she can study for her senior thesis project. Which of the following headlines refers to a microbe that she might find interesting?

Answer 87

"Brain-eating amoeba strikes two teens in one week"