UF MCB 3023 Final Exam

Which of the following components is characteristic of eukaryote membranes? Select all that apply.

Cholesterol

Hopanoids

Ergosterol

Cholesterol

Ergosterol

Which of the following functions is NOT associated to the membranes of the prokaryotes?

A. Protein secretion

B. Plasmid assembly

C. Transport

D. Osmotic barrier

B. Plasmid Assembly

Which of the following is true of viruses in the extracellular phase?

A. They can reproduce independently of living cells but only at a slow rate.

B. They behave as a macromolecular complex and are no more alive than are ribosomes.

C. They possess many different enzymes.

D. They possess many different enzymes and they can reproduce independently of living cells but only at a slow rate.

B. They behave as a macromolecular complex and are no more alive than are ribosomes.

Plasmids are extra-chromosomal DNA molecules that can be found as recombinant molecules into the chromosome of:

A. Viruses and Bacteria

B. Bacteria

C. Bacteria and Archaea

D. Archaea

E. Viruses

C. Bacteria and Archaea

In the Archaea envelopes the presence of a microcrystalline array of proteins (frequently glycosylated) is the most common structure to be found. This particular structure is also present in some group of Bacteria and it is called:

A. Inner membrane

B. Outer membrane

C. Lipopolysacharide (LPS)

D. S-Layer

D. S-Layer

Which of the following molecules is only found in the membrane of Gram negative Bacteria?

A. None of them.

B. Teichoic acids.

C. Cell wall with glycine inter-bridges.

D. Lipoteichoic acids.

E. All of them.

A. None of them

Which of the following components of the LPS is a potent endotoxin?

A. Ethanolamine

B. Lipid B

C. O side Chain

D. Lipid A

D. Lipid A

Carboxysomes are internal prokaryotic cell structures made of proteins. These polyhedral structures are TRUE cellular micro-compartments inside the prokaryotes cytoplasms. They contain enzymes (like Rubisco) involved in carbon dioxide fixation. (T/F)

True

Identify the list of compounds normally stored in form of inclusion bodies in the cytoplasm of prokaryotic cells.

A. None of them

B. glycogen - poly-B-hydroxybutyrate - polyphosphate - sulfur globules

C. glycogen - poly-B-hydroxybutyrate - water - sulfur globules

D. glycogen - poly-B-hydroxybutyrate - polyphosphate - water

B. glycogen - poly-B-hydroxybutyrate - polyphosphate - sulfur globules

Which of the following functions is NOT associated to the membranes of the prokaryotes?

A. Osmotic barrier

B. Protein secretion

C. Transport

D. Plasmid assembly

D. Plasmid Assembly

Which of the following cell wall characteristics is NOT VITAL for the cell?

A. Helps to determine the shape of the cell

B. Protect the cell from osmotic lysis

C. Protect the cell from toxic substances

D. All of them are vital

B. Protect the cell from osmotic lysis

Only one amino acid sequence of the following peptides is present in the Gram positive cell wall. It functions as an interbridge, connecting D-Ala and L-Lys to crosslink the peptidoglycan (it is called pentaglycine crosslink). Select the correct sequence:

A. Gly-Gly-Gly

B. D-Ala-Gly-Gly-D-Ala-Gly

C. Gly-Gly-Gly-Gly-Gly

D. Gly-Lys-Lys-Gly-Ala

C. Gly-Gly-Gly-Gly-Gly

A __________ layer consists of diffuse unorganized polysaccharide material that lies outside the cell wall and is easily removed.

Slime

The movement of molecules from an area of higher concentration to an area of lower concentration without the participation of specific carrier molecules is called

A. facilitated diffusion.

B. active transport.

C. passive diffusion.

D. osmosis.

C. Passive Diffusion

The term used to describe bacteria that have a spherical shape is

A. coccus.

B. vibrio.

C. bacillus.

D. coccobacillus.

A. Coccus

Which of the following protects bacteria from lysis in dilute solutions and helps to determine their cellular morphology or shape?

A. capsule

B. plasma membrane

C. gas vacuoles

D. peptidoglycan

D. Peptidoglycan

In the Gram-staining procedure, the counterstain is:

A. iodine.

B. alcohol.

C. safranin.

D. crystal violet.

C. Safarnin

Endospores represent a challenge to the fields of industrial and medical microbiology because:

A. endospore-forming organisms are often dangerous pathogens.

B. endospores are significantly smaller than vegetative cells.

C. endospores are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive, and endospore-forming organisms are often dangerous pathogens.

D. they are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive.

D. endospores are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive, and endospore-forming organisms are often dangerous pathogens.

The primary lipid components of the membranes of extreme thermophiles are

A. 40 carbon diglycerol tetraethers.

B. sulfolipids.

C. 20 carbon diglycerol diethers.

D. cholesterol.

A. 40 carbon diglycerol tetraethers.

Unlike members of the Bacteria, most archaeons have linear chromosomes with multiple origins of replication. (T/F)

False

feature unique to some archaeal plasma membranes is that they may

A. consist of a lipid bilayer that lacks integral membrane proteins.

B. contain sterols such as cholesterol.

C. consist of a lipid bilayer with embedded proteins.

D. consist of a lipid monolayer.

D. consist of a lipid monolayer.

Archaeons have been isolated from temperate and cold environments. (T/F)

True

Bacterial and archaeal ribosomes are known as _____ ribosomes, based on their sedimentation coefficient.

A. 30S

B. 70S

C. 50S

D. 80S

B. 70S

Viruses in the extracellular state possess few, if any, active enzymes. (T/F)

True

The formation of carbohydrate (CO2 fixation. in the dark reaction of photosynthesis, takes place in the

A. stroma.

B. nucleus.

C. thylakoid membrane.

D. cytoplasm.

A. stroma

Like bacteria and eukaryotic microorganisms, most viruses can be cultured using artificial media. (T/F)

False

In an enveloped virus, the part of the virus including the nucleic acid genome and the surrounding protein coat but not the envelope is called the

A. matrix.

B. nucleocapsid.

C. virion.

D. capsid.

B. Nucleocapsid

Which of the following diseases is (are. caused by prions?

A. Mad cow disease.

B. All of the choices.

C. Kuru and Creutzfeldt-Jakob Disease.

D. Scrapie.

B. All of the choices

Enzymes needed to digest all types of macromolecules are found in

A. mitochondria.

B. Golgi apparatus.

C. centrioles.

D. lysosomes.

D. Lysosomes

A (n. __________ is a special type of lysosome used by a cell to selectively digest and recycle cytoplasmic contents, such as mitochondria.

A. suicide vacuole

B. turnover lysosome

C. autophagosome

D. recycling vacuole

C. Autophagosome

Which of the following organelles is involved in the modification, packaging, and secretion of materials?

A. Centrioles

B. Golgi apparatus

C. Lysosomes

D. Mitochondria

B. Golgi Apparatus

The distribution of lipids in the plasma membrane of eukaryotes is symmetrical. (T/F)

False

Which of the following parts of the Golgi complex receives materials from the ER?

A. Cis face.

B. None of these are correct.

C. Cisternal edges.

D. Trans face.

A. Cis face

A process that destroys or inhibits microbes on living tissues is called

A. Antisepsis

B. Disinfection

C. Sanitation

D. Sterilization

A. Antiseptis

Which of the following groups functions as a broad-spectrum antibiotic?

A. Tetracyclines

B. Dapsone

C. Polymyxin B

D. Quinolones

A. Tetracyclines

The most important part of the penicillin molecule is the beta-lactam ring. (T/F)

True

Finding treatments for fungal infections is more difficult because

A. Antifungal drugs that kill fungi are also toxic to human cells

B. Most fungi have a detoxification system that modifies many antifungal agents

C. Antifungal drugs have a low therapeutic index

D. All of the above

D. All of the above

Which of the following questions must be considered when selecting an antimicrobial drug?

A. Can it reach the site of infection?

B. Is the pathogen susceptible to the drug?

C. Is the pathogen resistant to the drug?

D. All of the above

D. All of the above

Which of the following groups of antibiotic drugs functions as a metabolic antagonist?

A. Penicillins

B. Sulfonamides

C. Aminoglycosides

D. Quinolones

B. Sulfonamides

Greater contact time with an antimicrobial agent results in the killing of more microbes. (T/F)

True

Which of the following factors leads to antibiotic resistance to antimicrobial drugs?

A. Use of antibiotics as animal growth enhancers

B. Failure to complete course of antibiotic therapy

C. Inappropriate antibiotic prescribing practices

D. All of the above

D. All of the above

common form of moist heat sterilization in the laboratory is

A. Boiling water

B. The hot plate

C. The autoclave

D. Ultraviolet light

C. The autoclave

Which of the following antibiotics inhibits cell wall synthesis?

A. Macrolides

B. Vancomycin

C. Sulfonamides

D. Quinolones

B. Vancomycin

Which of the following is a reason for metabolic regulation?

A. Maintain cell components at appropriate levels.

B. Conserve materials.

C. Ensure efficient use energy stores.

D. All of the choices.

D. All of the choices

Cells carry out three major types of work; which of the following involves nutrient uptake and waste elimination?

A. Transport work.

B. None of these

C. Mechanical work.

D. Chemical work.

A. Transport work

The sum total of all chemical reactions occurring in a cell is called

A. metabolism.

B. anabolism.

C. none of the choices

D. catabolism.

A. Metabolism

Which of the following can be used as electron acceptors during anaerobic respiration?

A. sulfate

B. carbon dioxide

C. nitrate

D. all of the choices

D. All the choices

The pentose phosphate pathway produces

A. NADPH.

B. all of the choices.

C. CO2.

D. glyceraldehyde 3-phosphate.

B. All of the choices

Mitochondrial electron transport takes place

A. in the fluid matrix of the mitochondria.

on the outer mitochondrial membrane.

B. on the outer mitochondrial membrane and on the inner mitochondrial membrane.

C. on the inner mitochondrial membrane.

C. On the inner mitochondrial membrane

Which of the following is not a phase of the Calvin Cycle?

A. oxidation phase

B. reduction phase

C. carboxylation phase

D. regeneration phase

A. Oxidation phase

Which pathway(s) are used by eukaryotic microorganisms to fix carbon dioxide?

A. Reductive tricarboxylic pathway. B. None of the choices.

C. Calvin cycle.

D. Entner-Doudoroff.

C. Calvin Cycle

Large numbers of small monomeric molecules join together to form large molecules that are known as:

A. maximolecules.

B. polymolecules.

C. multimers.

D. macromolecules.

D. Macromolecules

A purine or pyrimidine that is attached to a sugar, either ribose or deoxyribose, is called a

A. nitrogenous base.

B. nucleic acid.

C. nucleotide. D. nucleoside.

D. Nucleoside

A purine or pyrimidine that is attached to a sugar, either ribose or deoxyribose, to which is attached one or more phosphate groups is called a:

A. nucleotide.

B. nucleoside.

C. nitrogenous base.

D. nucleic acid.

Nucleotide

A culture system with constant environmental conditions maintained through continual provision of nutrient and removal of wastes is called __________ culture system

A. continuous

B. batch

C. fed-batch

D. semicontinuous

A. Continuous

One of the major advantages of a continuous culture system is that the cells can be maintained in the exponential growth phase for extended periods of time. (T/F)

True

Which of the following can be used to isolate pure cultures of bacteria from mixtures?

A. spread plates

B. streak plates

C. pour plates

D. all of the choices

D. All of the choices

The purpose of the penicillin binding proteins is to link phospholipids together in the cellular membrane. (T/F)

False

Disinfection is normally used on inanimate objects.(T/F)

True

A process that reduces microbes to a level deemed safe by public health standards is called

A. Antisepsis

B. Disinfection

C. Sanitation

D. Sterilization

C. Sanitation

A process that destroys or inhibits microbes on living tissues is called

A. Antisepsis

B. Disinfection

C. Sanitation

D. Sterilization

A. Antisepsis

The process by which all living cells, spores, and acellular entities are either destroyed or removed from an object or habitat is called

A. Antisepsis

B. Disinfection

C. Sanitation

D. Sterilization

D. Sterilization

Phenolics act on microbes by

A. Dissolving membrane lipids

B. Denaturing proteins and disrupting cell membranes

C. Oxidizing cellular constituents

D. Precipitate cell proteins

B.Denaturing proteins and disrupting cell membranes

Some antimicrobials are static agents that reversibly inhibit microbial growth. (T/F)

True

Sulfonamides work by directly inhibiting nucleic acid synthesis. (T/F)

False

The most selective antibiotics are those that

A. Inhibit cell wall synthesis

B. Inhibit protein synthesis

C. Act as metabolic antagonists

D. Inhibit nucleic acid synthesis

A. Inhibit Cell Wall Synthesis

Which of the following antifungal drugs is used to treat superficial mycoses?

A. Amphotericin B

B. Clotrimazole

C. Pentamidine

D. All of the above

B. Clotrimazole

The energy required to bring the substrates of a reaction together in the correct way to reach the transition state is called

A. free energy.

B. activation energy.

C. enthalpy.

D. entropy.

B. Activation energy

The nonprotein component of an enzyme that is firmly attached to the protein is called a(n.

A. apoenzyme.

B. coenzyme.

C. holoenzyme.

D. prosthetic group.

D. Prosthetic group

Cells carry out three major types of work; which of the following involves energy for cell motility and the movement of structures within cells?

A. Chemical work.

B. Transport work.

C. Mechanical work.

D. None of these.

C. Mechanical group

Metabolic pathways can be either catabolic or anabolic but not both. (T/F)

False

The net gain of ATP per molecule of glucose metabolized to pyruvate using Entner-Doudoroff pathway is

A. 4

B. 2

C. 1

D. 0

1

In the process of fermentation an organic substrate, such as glucose, is reduced and an intermediate of the pathway, such as pyruvate, is oxidized. (T/F)

False

The major function/s. of the TCA cycle is/are.

A. energy production.

B. provision of carbon skeletons for biosynthesis of cell components.

C. electron transport.

D. energy production and provision of carbon skeletons for biosynthesis of cell components.

D. energy production and provision of carbon skeletons for biosynthesis of cell components.

The TCA cycle generates all of the following from each acetyl-CoA molecule oxidized except

A. three NADH molecules.

B. two CO2 molecules.

C. one FADH2 molecule.

D. two ATP or GTP molecules.

D. two ATP or GTP molecules

Synthesis of complex molecules from simpler ones with the input of energy is called

A. metabolism. B. anabolism. C. catabolism.D. amphibolism.

B. Anabolism

Which of the following is a source of carbon skeletons that are used in the synthesis of amino acids?

A. Acetyl-CoA. B. TCA cycle intermediates.

C. Glycolysis intermediates. D. All of the choices.

D. All of the choices

Which pathway(s) are used by eukaryotic microorganisms to fix carbon dioxide?

A. Calvin cycle. B. Reductive tricarboxylic pathway. C. Entner-Doudoroff. D. None of the choices.

A. Calvin cycle

The reduction of atmospheric nitrogen to ammonia is called

A. ammonification. B. nitrification. C. denitrification. D. nitrogen fixation.

D. Nitrogen fixation

Which of the following cofactors is very important in the synthesis of purines?

A. acetyl-CoA

B. cytidine diphosphate

C. folic acid

D. glutathione

C. Folic Acid

Cells save energy and materials by using many of the same enzymes for both __________ and __________.

Catabolism and anabolism

The strand of DNA for a particular gene that is copied by the RNA polymerase to form mRNA is called the __________ strand.

A. transcription

B. copy

C. leading

D. template

D. Template

The B form of the DNA double helix contains a wider major groove and a narrower minor groove because the two polynucleotide strands are not positioned directly opposite one another in the helical cylinder.(T/F)

True

The unexpressed regions of split genes are called

A. introns. B. exons. C. endons. D. codons.

A. Introns

The energy needed for protein synthesis is provided by the hydrolysis of

A. GTP

B. ATP and GTP

C. UTP

D. ATP and UTP

E. ATP

B. ATP and GTP

Cell-to-cell communication by quorum sensing has been shown to be important in the regulation of genes neede

A. plasmid transfer.

B. all of the choices.

C. biofilm production.

D. virulence.

B. All of the choices

The terminator versus anti-terminator function of the T box-based riboswitch used by Gram-positive bacteria to regulate amino acid-related genes is determined by

A. the utilization of the appropriate sigma factor by RNA polymerase.

B. the binding of the T box binding protein.

C. the binding of the appropriate uncharged tRNA.

D. the rate of leader peptide synthesis.

C. the binding of the appropriate uncharged tRNA.

An operon network that is under the control of a common regulatory protein while each operon is still also under the control of its own unique regulatory protein is most specifically referred to as

A. webulon.

B. regulon.

C. modulon.

D. complexon.

C. Modulon

Which of these transposable elements do not carry genes for functions other than those needed for transposition?

A. conjugal transposons

B. insertion sequences

C. retrotransposons

D. composite transposons

B. insertion sequence

When bacterial genes are transferred to another bacterium by a virus, it is called

A. transduction. B. transfection.

C. transformation. D. conjugation.

A. Transduction

Mutations that result in the death of an organism when expressed are called __________ mutations.

A. conditional

B. recessive

C. lethal

D. dominant

C. lethal

Which of the following can be used as vectors for cloning DNA fragments?

A. bacteriophages.

B. all of the choices.

C. plasmids.

D. cosmids.

B. All of these choices

Which of the following is not part of a yeast artificial chromosome (YAC)?

A. The F factor

B. A selectable marker

C. An ARS.

D. A CEN sequence.

A. The F factor

The polymerase chain reaction (PCR) can be used to produce __________ of copies in a few hours.

A. millions

B. thousands

C. billions

D. hundreds

C. billions

The Southern blotting technique for transferring DNA from an agarose gel to a piece of nitrocellulose membrane is named for E. M. Southern, the person who developed the procedure. (T/F)

True

Promoters for genes that code for proteins can be isolated from a cDNA library.(T/F)

False

Genome analysis has revealed that horizontal gene transfer is frequently mediated by phages. (T/F)

True

The microbiome represents all the genes present in the trillions of microbes living on and in adult humans. (T/F)

True

When two or more genes from the same genome have nucleotide sequences so alike that they most probably arose from gene duplication those genes are called

A. homologs.

B. orthologs.

C. paralogs.

D. duologs.

C. Paralogs

Modern automated sequencing machines detect DNA bands by measuring incorporated radioactivity. (T/F)

False