BIOL 246 Final

Final exam study set

Which of the traits is absent from some cellular microbes?
a. a nucleus with a nuclear membrane
b. a phospholipid bilayer
c. enzymes that are needed for metabolism
d. ribosomes required for protein sythesis

a. a nucleus with a nuclear membrane

Microbes live on us, in us, and everywhere. Which activities are microbes involved in?
a. nitrogen fixation
b. fermentation of alcohol
c. decomposing dead matter
d. supporting our health
e. all of the above

e. all of the above

Which of the following pairs is mismatched?
a. Hooke + cell theory
b. Jenner - vaccines
c. Van Leeuwenhoek - germ theory
d. Lister - aseptic surgery
e. Pasteur - fermentation

c. Van Leeuwenhoek - germ theory.
Germ theory was Ignaz Semmelweiss and Joseph Lister. Van Leeuwenhoek was the first to observe living microbes

An agent that reproduces in cells but is NOT composed of cells and contains RNA as it's genetic material is a(n):
a. alga
b. bacterium
c. fungus
d. helminth
e. virus

e. virus

You are looking at a white cottony growth on a culture medium. Microscopic examination reveals it is multicellular. Which os the following conclusions about this organism is false?
a. it has cell walls
b. it has DNA enclosed in a nucleus
c. it is eukaryotic
d. it is a bacterium
e. it absorbs organic nutrients

d. it is a bacterium.
The microbe multicellular which means it cannot be a bacterium since they are all unicellular

Which of the following applies ONLY to archae?
a. these microbes have no nucleus
b. these microbes have mitochondria
c. these microbes are not true cells
d. these microbes have never been shown to cause a disease
e. these microbes are unicellular

d. these microbes have never been shown to cause a disease

Which os the following statements about biofilms is false?
a. compared to free-living bacteria, biofilms are more sensitive to antibiotics
b. biofilms in pipes block the flow of water
c. biofilms in your body protect mucous membranes from harmful microbes
d. biofilms on medical implants cause infections
e. biofilms on rocks provide food for animals

a. compared to free-living bacteria, biofilms are more sensitive to antibiotics.
Because biofilms are a culmination of different bacteria, they are much less sensitive to antibiotics and are more difficult to treat

All bacteria are/have:
a. unicellular
b. flagella
c. 70S ribosomes
d. a and b
e. a and c

e. a and c
all bacteria are unicellular and all bacteria have 70s ribosomes. not all bacteria have

What do genes consist of?
a. carbohydrates
b. lipids
c. proteins
d. nucleic acids
e. both c and d

d. nucleic acids

The antimicrobial drug imidazole inhibits sterol synthesis. This would most likely interfere with:
a. bacterial cell walls
b. fungal cell walls
c. eukaryotic plasma membranes
d. prokaryotic plasma membranes
e. genes

c. eukaryotic plasma membranes

Anaerobes cannot grow in the presence of oxygen because:
a. anaerobes cannot use oxygen to generate ATP
b. anaerobes have thick walls that are impermeable to oxygen
c. anaerobes do not have enzymes to detoxify oxygen by products
d. oxygen cannot be incorporated as part of the anaerobe's proteins
e. oxygen is not required in fermentation

c. anaerobes do not have the enzymes to detoxify oxygen by products

Which of the following is NOT a distinguishing characteristics of prokaryotic cells?
a. their DNA is not enclosed within a membrane
b. they lack membrane enclosed organelles
c. they have cell walls containing peptidoglycan
d. their DNA is not associated with histones
e. they lack a plasma membrane

e. they lack a plasma membrane

The curve in Pasteur's swan neck flasks was important because:
a. it prevented flies from escaping the flask
b. it trapped microbes that would have otherwise entered the flask
c. it allowed warm air to reach the broth
d. it prevented oxygen rom reaching the broth
e. none of the above

b. it trapped microbes that would have otherwise entered the flask

Endospores are important in certain pathogen's lifecycle because:
a. they resist heat and disinfection
b. they are viable for long periods of time
c. they inhibit the host's immune response
d. all of the above
e. a and b only

e. a and b only

Which of the following is NOT a chemical component of a bacterial cell well?
a. cellulose
b. peptidoglycan
c. teichoic acids
d. peptide chains
e. n-acetylmuramic acid

a. cellulose

Which has a toxic cell wall?
a. gram -ve
b. gram +ve
c. both a and b
d. neither

a. gram -ve
gram -ve cell walls contain lipid A, which is an Endotoxin

Which cell cell is easily discolored by alcohol?
a. gram -ve
b. gram +ve
c. both a and b
d. neither

a. gram -ve
gram -ve bacteria have a thin peptidoglycan layer, versus the gram +ve bacteria which have a very thick peptidoglycan layer

Which cell wall contains teichoic acids?
a. gram -ve
b. gram +ve
c. both a and b
d. neither

b. gram +ve

Which cell wall protects against osmotic lysis?
a. gram -ve
b. gram +ve
c. both a and b
d. neither

c. both a and b

When bacteria are inoculated into a new sterile nutrient broth, their numbers don't begin to increase immediately. Instead, there isa lag phase that may last for an hour or even several days. Why don't bacterial numbers increase immediately?
a. the medium contains inhibitors that prohibit rapid growth of the bacteria, and these must be inactivated before the bacterial numbers will increase
b. the bacteria have to establish a biofilm before their numbers can increase
c. the bacteria must adjust to the nutrient content in the new medium, synthesizing necessary amino acids, growth factors, and enzymes
d. there are not enough nutrients for the bacteria to grow, and growth is delayed until there are some dead cells to cannibalize
e. none of the above reasons

c. the bacteria must adjust to the nutrient content in the new medium, synthesizing necessary amino acids, growth factors, and enzymes

Penicillin controls the growth of some bacteria by:
a. destroying the cell membrane
b. inhibiting all protein synthesis
c. removing the cell wall
d. preventing peptidoglycan synthesis
e. inhibiting DNA replication

d. preventing peptidoglycan synthesis

Which of the following is not a common bacterial shape?
a. cocci
b. rods.
c. disc
d. spirochete
e. bacilli

d. disc

Which of the following statements about substrate-level phosphorylation is false?
a. it involves the direct transfer of high-energy phosphate group from a phosphorylated metabolic compound to ADP
b. it does not involve electrons transferred between compounds
c. it occurs in glycolysis
d. the oxidation of intermediate metabolic compounds releases energy that is used to generate ATP
e. it occurs in the Krebs cycle

d. the oxidation of intermediate metabolic compounds releases energy that is used to generate ATP

Substrate-level phosphorylation is one of the 3 ways organisms form ATP by adding phosphoryl group to ADP.

ADP = Adenosine + 2 Phosphate groups
ATP = Adenosine + 3 Phosphate groups

Which of the following is the best definition of fermentation?
a. the reduction of glucose to pyruvic acid
b. the oxidation of glucose with organic molecules serving as electron acceptors
c. the complete catabolism of glucose to CO2 and H2o
d. the production of energy by substrate-level phosphorylation
e. the production of ethanol from glucose

b. the oxidation of glucose with organic molecules serving as electron acceptors

Which of the following statements are true?
a. all bacteria are prokaryotic organisms
b. all bacteria are unicellular
c. all fungi are eukaryotic
d. all cells have a cell wall
e. a, b, and c

e. a, b, and c
mycoplasma are a bacteria but they lack a cell wall, so d is not true

Most human pathogens are:
a. thermophiles and acidophiles
b. mesophiles and neutrophiles
c. psychrophyles and halophiles
d. thermophiles and halophiles
e. mesophiles and acidophiles

b. mesophiles and neutophiles
Mesophiles: moderate temp. loving, 10-47 °C
Optimum: 25-40 °C, human body temp is 37°C

Neutrophiles: pH 6.5-7.5, body pH is about 7

Which type of organism will use O2 when it is available but will live without it if it is not?
a. facultative anaerobes
b. obligate anaerobes
c. microaerophiles
d. obligate aerobes
e. aerotlerant

a. facultative anaerobes
obligate anaerobes cannot live at all in the presence of oxygen. obligate aerobes cannot live at all without the presence of oxygen. microaerophiles need oxygen to survive but are killed when it very high concentrations of oxygen. Aerotlerant microbes can survive in the presence of oxygen but do not need to for growth

Which is the correct order of taxonomic categories, going from most specific to most general?
a. domain, kingdom, phylum, class, order, genus
b. division, domain, kingdom, class, genus, family
c. species, genus, family, order, class, phylum, kingdom
d. species, family, class, order, phylum, kingdom
e. genus, species, family, order, class, phylum, kingdom

c. species, genus, family, order, class, phylum, kingdom

**dreary kings play chess on fancy glass sets

Acellular entities that are obligate intracellular parasites are:
a. archae
b. yeasts
c. molds
d. viruses
e. protozoa

d. viruses

Which of the following is NOT a function or characteristic of capsules?
a. it forms extensions that increase motility of organisms
b. it can protect the cell against dehydration
c. it allows the organisms to stick to surfaces
d. it is usually made of carbohydrates and proteins
e. it is antiphagocytic

a. it forms extensions that increase motility of organisms
Pili form extensions to transfer genetic material from bacteria to bacteria

Fimbriae and Flagella are used for motility

You have isolated a new organism from a salty lake. Upon microscopic observation you notice that it is unicellular, has a cell wall, lysosomes, and mitochondria. It is most probably going to be classified under:
a. prokaryotae
b. eukarya
c. monera
d. archae
e. eubacteria

b. eukarya
prokaryotae do not have mitochondria, eubacteria are prokaryotic, prokaryotes fall under "monera", and archae are prokaryotic

Which of the following is true of scientific names assigned to living organisms?
a. the scientific name often includes the common name, such as Yeast of Human
b. the entire scientific name is always capitalized
c. the scientific name is made up of a single kingdom name
d. the scientific name is always underlined or italicized
e. the scientific name only includes the genus of an organism

d. the scientific name is always underlined or italicized

You have a fresh culture of Staphylococcus aureus growing in a medium. This bacterium replicates every 30 minutes. If you start with 8.9 x 10^5 bacteria, after 3 hours, you will have ______ bacteria:
a. 8.9 x 10^7
b. 5.7 x 10^6
c. 5.7 x 10^7
d. 4.6 x 10^6
e. 2.3 x 10^8

c. 5.7 x 10^7

Mf = Mi x 2^n ... n = 1 generation

the bacteria replicates every 30 minutes so after 3 hours it will have generated 6 times. n = 6. Mi = 8.9 x 10^5. Mf = (8.9 x 10^5) x 2^6 = 5.7 x 10^7

During aerobic respiration:
a. pyruvic acid is converted to ethanol
b. each NADH produces 4 ATP molecules
c. one molecule of ATP is produced when glucose is oxidized to pyruvic acid
d. the complete oxidation of 2 glucose molecules produces 70 ATP molecules
e. during kreb's cycle, 6 NADH and 2 FADH2 are produced from one glucose molecule

e. during kreb's cycle, 6 NADH and 2 FADH2 are produced from one glucose molecule

Aerobic Respiration =
Glycolysis: -2 ATP, +2 ATP +2 ATP = net 2 ATP; 2 NADH
Prep Stage: 0 ATP, 2 NADH
Kreb's Cycle: +2 ATP, +6 NADH, +2 fADH2

Total = 4 ATP, 10 NADH, 2 fADH2 from 1 glucose molecule

1 NADH = 3 ATP
1 fADH2 = 2 ATP

1 glucose molecule = 4 ATP + 3 (10 NADH) + 2 (2 fADH2) = 4 ATP + 30 ATP + 4 ATP = 38 ATP total

The tolerance of facultative anaerobic bacteria to superoxide ion is due to:
a. lack of chytochrome C oxidase
b. lack of peroxidase
c. presence of superoxide dismutase and catalase
d. inability to form superoxide radicals
e. the pumping of superoxide ions out of the cell

c. presence of superoxide dismutase and catalase

How many ATP molecules are produced from the fermentation of 4 glucose molecules to lactic acid by a bacterium?
a. 2
b. 4
c. 6
d. 8
e. 10

d. 8

glucose molecules are fermented into lactic acid in glycolysis. during glycolysis, 2 net ATP are produced, and 2 NADH are produced. 1 NADH = 3 ATP, so 2 NADH = 6 ATP. 6 ATP + 2 ATP = 8 ATP

Enzymes are biological catalysts because:
a. they speed up the rate of a reaction
b. they are never used up in a reaction
c. they decrease the activation energy of a reaction
d. a and b
e. a, b, and c

e. a, b, and c

Robert Koch's studies on Bacilllus anthracis established a sequence of experimental steps to prove that microbes:
a. cause disease
b. recycle elements such as nitrogen
c. control insect pests
d. produce antiviral compounds
e. can be altered to produce products such as human insulin

a. cause disease
He extracted this bacterium from a sheep which had died of anthrax, grew it and injected a mouse with it. The mouse developed the disease as well.

Which of the following are correctly matched?
a. Koch and microscopy
b. Fleming and antibiotics
c. Pasteur and antisepsis
d. Ehrlich and vaccinations
e. Van Leewenhoek and spontaneous generation

b. Fleming and antibiotics

Microscopy - Van Leewenhoek
Antisepsis - Lister
Vaccinations - Jenner
Spontaneous generation - Needham, Spallanzani

All of the following concerning the gram positive cell wall are true except:
a. it contains a backbone of NAG - NAM joined by beta 1,4 linkage
b. the lipid A embedded in the peptidoglycan can cause fever and shock
c. the teichoic acids can be attached to the thick peptidoglycan layer
d. it is important in protecting the cell from osmotic lysis
e. tetrapeptides re found attached to the NAM component of the peptidoglycan

b. the lipid A embedded in the peptidoglycan can cause fever and shock

lipid A is only found in gram -ve bacteria

Which statement concerning glycolysis is false:
a. one end product of glycolysis is 2 molecules of NADH
b. substrate level phosphorylation occurs during glycolysis
c. glycolysis is a common step in both respiration and fermentation
d. during glycolysis 2 net molecules of ATP are generated from 1 glucose molecule
e. glucose is reduced to CO2 and H2O

e. glucose is reduced to CO2 and H2O

During the stationary phase of bacterial growth:
a. the number of new bacteria is equal to the number of dead bacteria
b. the number of new bacteria is less than the number of dying bacteria
c. the number of newly generated cells is larger than the number of dying cells
d. the bacteria are neither dying nor replicating
e. none of the above

a. the number of new bacteria is equal to the number of dead bacteria

During the oxidation of glucose in glycolysis, electrons are transferred to:
a. lactic acid
b. NAD+
c. NADH
d. fADH2
e. FAD+

b. NAD+
In glycolysis, glucose is oxidized into 2 pyruvic acids, 2 ATP, and 2 NADH.

(NAD+) + (Hydrogen) = NADH

In bacteria, the cell membrane functions in all of the following ways except:
a. regulates movement of the materials in and out of the cell
b. synthesizes cell wall components
c. is the site for protein synthesis
d. assists with DNA replication
e. is the site for ATP production

c. is the site for protein synthesis

protein synthesis takes place in the cytoplasm, not the cell membrane

Factors giving bacteria resistance to antibiotics can be carried on small structures called:
a. nuclei
b. mitochondria
c. plasmids
d. ribosomes
e. nuceloids

c. plasmids

plasmids are an extra chromosomal piece of circular DNA, usually carries genes that are not essential for survival

A fungus growing on a piece of bread in your refrigerator is a:
a. thermophile
b. acidophile
c. psychrophile
d. halophile
e. mesophile

c. psychrophile

Psychrophiles = cold loving, 0-15 °C

Which of the following are important in attachment of bacteria to host cells?
a. plasma membrane - flagella
b. fimbriae - capsules
c. fimbriae - endospores
d. plasmids - capsules
e. cilia - capules

b. fimbriae - capsules

A bacterial cell is found to be resistant to high temperatures, phagocytosis, and lives in high salt concentrations. Which of the following describes it best?
a. acidophile, endospore, fimbriae
b. acidophile, capsule, fimbriae
c. halophile, endospore, capsule
d. halophile, cell wall, endospore
e. mesophile, halophile, fimbriae

c. halophile, endospore, capsule

Halophile = salt loving
Capsule = resistant to phagocytosis
Endospore = makes bacteria resistant to high temperatures

Which of the following regarding the peptidoglycan layer is false?
a. the cross bridges link the NAM together and increase the strength of the layer
b. it contains long polymers of N-acetylglucoseamine (NAG) and N-acetylmuramic acid (NAM)
c. Tetrapeptides are attached to the NAM
d. Lysozyme can break the NAG-NAM bonds
e. it is only found in gram negative rod shaped organisms

e. it is only found in gram negative rod shaped organisms

peptidoglycan is found in both gram +ve and gram -ve baceria

Which of the following is NOT true of the gram -ve outer membrane?
a. it has polysaccharide antigens that are useful in bacterial identification
b. it contains lipids also known as endotoxins
c. it contains lipopolysaccharide
d. it is part of the gram -ve cell wall
e. it contains enzymes for energy synthesis

e. it contains enzymes for energy synthesis

Which of the following supports the endosymbiotic theory?
a. mitochondria and bacteria have 70s ribosomes
b. DNA is the genetic information of all cells
c. mitochondria and bacteria have cell membranes
d. mitochondria and bacteria have peptidoglycan
e. none of the above

a. mitochondria and bacteria have 70s ribosomes

The endosymbiotic theory is an evolutionary theory that explains the origin of eukaryotic cells from prokaryotes. It states that several key organelles of eukaryotes originated as a symbiosis between separate single-celled organisms.

You have isolated a motile gram +ve cell with no visible nucleus. You can assume that this cell has:
a. ribosomes
b. mitochondria
c. endoplasmic reticulum
d. fimbriae
e. all of the above

a. ribosomes
all bacteria have ribosomes. bacteria do not have mitochondria or endoplasmic reticulum because they are not eukaryotic and therefore have no membrane bound organelles, fimbriae are not found on all bacteria

Mycoplasmas are bacteria that:
a. lack a cell membrane
b. lack peptidoglycan
c. have sterols in the phospholipids
d. a and b
e. b and c

e. b and c

Mycoplasma have no cell wall, so they lack peptidoglycan and no bacteria has sterols except for mycoplasma

Which of the following structures increases the virulence of an organism?
a. capsule
b. cell wall
c. ribosomes
d. flagella
e. nucleus

a. capsule

cell wall, ribosomes, flagella, and nuclei are not virulence factors

The definition of generation time in bacteria is:
a. the time it takes for the lag phase
b. the time it takes for the bacteria to double in number
c. the time it takes for nuclear division
d. the time it takes from log to the end of stationary phase
e. the time it takes to generate endospores

b. the time it takes for the bacteria to double in number

Which of the following statements best describes what happens when a bacterial cell is placed in a solution containing 5% NaCl?
a. surcrose will move into the cell from a higher to a lower concentration
b. the cell will undergo osmotic lysis
c. water will move out of the cell
d. water will move into the cell
e. no change will result, the solution is isotonic

c. water will move out of the cell

this is an example of a hypertonic solution. the concentration of solutes outside the cell is greater the concentration of solutes inside the cell, causing plasmolysis to occur

Endospores are mainly produced by the genus:
a. Staphylococcus
b. Bacillus
c. Clostridium
d. Escherichia
e. b and c

e. b and c

The usefulness of antibiotics is hampered by:
a. the emergence of antibiotic resistant bacteria
b. the limited types of antibiotics available
c. difficulties encountered in mass production
d. their inability to kill gram -ve bacteria
e. an antibiotic's lack of specificity for bacterial versus animal cells

a. the emergence of antibiotic resistant bacteria

Which of the following is a mismatch?
a. mitochondria - ATP generation
b. lysosomes - digestive enzymes
c. endoplasmic reticulum - protein and lipid synthesis
d. gogli apparatus - secretion
e. ribosomes - storage

e. ribosomes - storage

ribosomes are used in protein synthesis, not for storage

An organism that can make all of its organic compounds and food from CO2 using energy from the sun is a:
a. photoautotroph
b. chemoautotroph
c. photoheterotroph
d. chemoheterotroph
e. none of the above

a. photoautotroph

Chemotrophs are organisms that obtain energy by the oxidation of electron donors in their environments. photoheterotrophs are organisms that use light for energy, but cannot use carbon dioxide as their sole carbon source. chemoheterotrophs are unable to utilize carbon dioxide to form their own organic compounds.

Which of the following is a mismatch?
a. fungi - always multicellular
b. grape-like clusters - Staphylococci
c. lipid A - endotoxin
d. gram -ve cells - appear pink after a gram stain
e. axial filaments - spirochetes

a. fungi - always multicellular

fungi can be multicellular (molds) or unicellular (yeasts)

Metabolic pathways in which complex larger organic molecules are converted into smaller organic molecules and/or inorganic molecules are called:
a. biosynthetic
b. endergonic
c. catabolic
d. anabolic
e. reversible

c. catabolic

catabolic = larger --> smaller
anabolic = smaller --> larger

True or false: Yeasts are unicellular, have circular chromosomes, and produce ATP in their mitochondria

false

yeasts produce ATP in the cytoplasm, not the mitochondria

True or false: Anaerobic respiration is another name for fermentation

false
Both fermentation and anaerobic respiration are types are carbohydrate catabolism, but they have differentl final electron receptors. In fermentation, the final electron receptor is an organic molecule that is not O2. in anaerobic respiration, the final electron receptor is an inorganic molecule

True or false: During the stationary phase, bacteria continue to undergo binary fission

true

True or false: Shrinking of the cell membrane in a bacterium in the presence of high osmotic pressure is called plasmolysis

true

True or false: The cell membranes of bacteria are responsible for the shape and gram reaction of the organism

false

the cell walls of the bacteria are responsible for the gram reaction

True or false: If you observe a rod shaped bacterium with a red color after a gram stain, you can assume that their cell wall contains lipopolysaccharide

true

gram -ve bacteria stain red/pink and contain lipopolysaccharides in their cell wall

True or false: In general, ATP is produced in catabolic pathways and expended in anabolic pathways

true

Which of the following is mis-matched?
a. Thiomargerita - gram -ve coccus
b. Yersinia - gram -ve rod
c. Vibrio - gram -ve comma shaped rod
d. Clostridium - gram +ve rod
e. Salmonella - gram +ve rod

e. Salmonella - gram +ve rod

Salmonella is a gram -ve rod

The furniture in a hospital room where an Ebola patient was staying needs to be sterilized. Which of the following methods would you recommend?
a. washing the whole furniture with clorox several times
b. spraying the furniture with glutaraldehyde
c. exposing the furniture to ethylene oxide gas in a chamber
d. rubbing all the furniture with a 100% alcohol solution
e. spraying al the furniture with phenol

c. exposing the furniture to ethylene oxide gas in a chamber

Which of the following concerning viruses is false?
a. most RNA viruses replicate in the cytoplasm of the cell using their RNA dependent RNA polymerase
b. most enveloped viruses penetrate the cell by fusion of their envelopes with the cell membrane of the host cell
c. herpesviruses are examples of latent viruses that persist in the body
d. uncoating in viral replication always follows the biosynthesis phase
e. all viruses use the cell's ribosome to translate their proteins

d. uncoating in viral replication always follows the biosynthesis phase

Replication uses a 5-step sequence:
Adsorption
Penetration
Uncoating
Biosynthesis
Assembly
Release

Which of the following is a mismatch?
a. virus spikes - used for attachment to host cell
b. molds - have cell membrane with sterols
c. R plasmids - are required for conjugation to occur
d. Saccharomyces cerevisiae - a common baker's yeast
e. dermatophytes - also called cutaneous mycosis

c. R plasmids - are required for conjugation to occur

F plasmid are required for conjugation to occur

Which of the following statements regarding the virus that causes AIDS is false?
a. this is a retrovirus
b. this virus uses reverse transcriptase
c. the virus is a lytic virus
d. the virus is called HIV
e. the virus has ss RNA as its genome

c. the virus is a lytic virus

HIV is a lysogenic virus, not a lytic virus

By definition, an oncogenic virus is one that causes:
a. respiratory illness
b. tumors
c. immunodeficiencies
d. only contain RNA
e. severe rashes

b. tumors

You perform a gram stain on a pus containing discharge from the cervix of a patient and you see gram -ve diplococci. The most likely organism is:
a. Neisseria gonorrhea
b. Streptococcus pneumonia
c. Epulopscium fisheloni
d. Thiomargertia namebiensis
e. Staphylococcus aureus

a. Neisseria gonorrhea (always diplococci)

Streptococcus pneumonia = gram +ve
Epulopscium fisheloni = gram +ve
Thiomargertia namebiensis = gram -ve cocci
Staphylococcus aureus = gram +ve

A fungal infection that spreads throughout the body is:
a. athlete's foot
b. systemic mycosis
c. cutaneous mycosis
d. systemic mycobacteriosis
e. ringworm

d. systemic mycobacteriosis

How are the Staphylococci different from the Streptococci when viewed after a gram stain?
a. Staphylococci are gram +ve, Streptococci are gram -ve
b. Staphylococci are gram +ve cocci, Streptococci are gram +ve rods
c. Staphylococci are gram -ve bacilli, Streptococci are gram -ve cocci
d. Staphylococci are gram +ve cocci, Streptococci are gram +ve cocci in chains
e. They cannot be differentiated microscopically

d. Staphylococci are gram +ve cocci, Streptococci are gram +ve cocci in chains

The best definition of a virus is:
a. an obligate intracellular parasite with both DNA and RNA as genetic material
b. an obligate intracellular parasite with either DNA or RNA as genetic material
c. a small genome covered by a protein coat
d. a self-replicating protein
e. a filterable prokaryotic agent with an envelope

b. an obligate intracellular parasite with either DNA or RNA as genetic material

Which of the following organisms has been implicated commonly with nosocomial infections?
a. Legionella pneumophila
b. Staphylococcus aureus
c. Pseudomonas aeruginosa
d. a and b
e. b and c

e. b and c

Which of the following statements about generalized transduction is true?
a. the virus is usually a lysogenic bacteriophage
b. both bacterial and viral DNA are found in the bacteriophages
c. any piece of the bacterial genome can be transferred by the phage
d. all of the above
e. none of the above

c. any piece of the bacterial genome can be transferred by the phage

Generalized transduction occurs during the lytic cycle of viruses. Sometimes bacterial DNA is packaged in the phage capsid during phage assembly by accident.

The presence of ________ in a water sample usually indicates a fecal contamination:
a. Mycobacteria
b. Staphylococcus
c. E. coli
d. Clostridium
e. Bordetella

c. E. coli

Which of the following will NOT destroy endospores?
a. autoclaving
b. hot air sterilization
c. pasteurization
d. ethylene oxide gas
e. none of the above

c. pasteurization

pasteurization is the use of heat to destroy microbes and is a disinfectant. Does not sterilize, so it will not kill endospores.

Which of the following would be the first step in biosynthesis of a virus with a - (minus) strand of RNA?
a. synthesis of DNA from an RNA template
b. synthesis of m-RNA from an RNA template
c. sythesis of double-stranded RNA from DNA template
d. transcription of mRNA from DNA
e. synthesis of DNA from a DNA template

b. synthesis of m-RNA from an RNA template

-RNA strands cannot perform protein synthesis because they re not in the form on mRNA. RNA polymerase makes template strands. The template strands can be translated in capsomere proteins used to assemble new viral capsids.

Which sequence is the best target for damage by UV radiation?
a. ACATGTCA
b. AGGTACA
c. ACCTCAA
d. TATTCGC
e. TACGTAT

d. TATTCGC

UV light is a form of non-ionizing radiation that can cause change in the DNA (mutation). Exposure to UV light causes adjacent thymines (T) to become cross-linked, forming a thymine dimer and disrupting their normal base pairing. TATTCGC was the only answer that had 2 thymines next to each other.

Rickettsias are different from most bacteria because:
a. they lack a cell wall
b. they are obligate intracellular parasites
c. they are gram -ve helical bacteria
d. they only cause disease in other bacteria
e. they grow in the roots of some plants

b. they are obligate intracellular parasites

All of the following are gram -ve except:
a. Legionella
b. Haemophilus
c. Epulopsium
d. Bordetella
e. Helicobacter

c. Epulopsium

Which of the following organisms is a gram +ve rod, highly resistant to desiccation, and has mycolic acids in it's cell wall?
a. Mycoplasma pneumoniae
b. Borrelia burgdorferi
c. Mycobacterium leprae
d. Legionella pneumophilia
e. Rickettsia rickettsii

c. Mycobacterium leprae

During DNA replication:
a. the leading strand is synthesized in 3' to 5' direction
b. the leading strand is synthesized discontinuously
c. the lagging strand is synthesized in 5' to 3' direction
d. both strands are synthesized discontinuously
e. both strands are replicated by RNA polymerase

c. the lagging strand is synthesized in 5' to 3' direction

Upon completion of conjugation between an F+ and F-:
a. the F- cell will now be able to transfer plasmid genes
b. the F- cell will now have a pilus
c. the F- cell will now become an F+ cell
d. the F+ cell becomes and F- cell
e. only a, b, and c

e. only a, b, and c

F+ cells do not retrograde into F- cells

Which of the following is a gram -ve rod that is a major inhabitant of the intestines of animals and can grow at 43C?
a. Escherichia
b. Bacteroides
c. Staphylococcus
d. Treponema
e. Campylobacter

e. Campylobacter

Campylobacter is a gram -ve rod that causes food poisoning

Which of the following concerning general characteristics of fungi is false?
a. fungi can be unicellular and multicellular eukaryotic organisms
b. fungi are found in soil
c. fungi are chemheterotrophs
d. fungi produce ATP at their cell membranes
e. fungi have cell membranes with ergosterols

d. fungi produce ATP at their cell membranes

Fungi produce ATP in the cytoplasm

Ringworm infections are:
a. caused by dermatophytes
b. the only contagious mycotic infections
c. can be acquired by sharing towels and socks
d. a and c
e. a, b, and c

e. a, b, and c

The sequence of events during the replication of retroviruses are:
a. attachment, replication, penetration, assembly, release
b. attachment, penetration, uncoating, synthesis, maturation, release
c. attachment, penetration, uncoating, integration, synthesis, maturation, release
d. attachment, penetration, eclipse, integration, maturation, release
e. attachment, maturation, synthesis, release

c. attachment, penetration, uncoating, integration, synthesis, maturation, release

A drug that destroys ergosterols in cell membranes can be used in the treatment of:
a. athlete's foot
b. the flu
c. a systemic fungal infection
d. a bacterial throat infection
e. either a or c

e. either a or c

ergosterols are only found in fungi, so a drug that destorys ergosterols would only be effective in treating fungal infections

Which of the following in NOT a step in translation?
a. transport of amino acids by t-RNA
b. joining of adjacent amino acids by peptide bonds
c. starting at an AUG codon
d. using the ribosome
e. joining okazaki fragments

e. joining okazaki fragments

okazaki fragments are not found in translation, they are found in DNA replication

Which of the following is mismatched?
a. Moraxella - gram -ve cocci
b. Hepatitis B virus - liver cancer
c. translation - occurs in the cytoplasm in both prokaryotes and eukaryotes
d. viral envelopes - made on the ribosome before lysing the cell
e. DNA ligase - joins small pieces of DNA

d. viral envelopes - made on the ribosome before lysing the cell

In viral replication, the mature retrovirus leaves the host cell, acquiring an envelope and attachment spikes as it buds out. Ribosomes are not involved this event.

A silent mutation:
a. can occur as a result of a point mutation
b. is possible because the genetic code is degenerate
c. will usually have deadly effects on the organism
d. a and b
e. a, b, and c

d. a and b

silent mutations are a type of point mutation/base substitution where no change occurs in the amino acid or protein sequence because the genetic code is degenerate. Essentially, the group of amino acids in the new strand create the same codon as they did before, so the sequence remains the same.

If you were the scientist to create an Ebola vaccine, you will ideally want one that:
a. destroys its RNA
b. block its receptors for attachment
c. inhibit penetration into the cell
d. inhibit synthesis of its proteins
e. arrest its exit from cells

b. block its receptors for attachment

without attachment, there is not way for a virus to replicate/spread

Which of the following is mismatched?
a. all DNA viruses - have nucleic acid and envelopes
b. a +ve ss RNA - can act directly as a messenger RNA
c. Streptococcus pneumoniae - gram +ve alpha hemolytic diplococci
d. Haemophilus influenza - does not cause the flu
e. dimorphic fungi - can change from yeasts to molds

a. all DNA viruses - have nucleic acid and envelopes

not all DNA viruses have envelopes