Microbiology Exam 1: MCQ and Vocab

Which is a component of all micro-organisms (but not all microbes)?

a. Genetic material b. Nucleus c. Cell Membrane d. Proteins

c. Cell Membrane

Which is an appropriate way to write the bacterial name?

a. E. coli b. Escherichia coli c. e. coli d. a and b

b. Escherichia coli

Which is a reasonable size estimate for an average virus?

a. 80 nm b. 0.8 μm c. 80 μm d. 8 cm

a. 80 nm

A single-celled eukaryotic microbe that is heterotrophic and has a cell wall is likely a(n)

a. Bacterium b. Algae c. Fungus d. Protozoan

c. Fungus

A bacterium with teichoic acids in its peptidoglycan but without lipopolysaccharide is

a. Gram + b. Gram - c. Mycoplasma d. Endospore-forming

a. Gram +

Lysozyme kills cells by

a. Cutting bonds cross-linking the chains of NAG and NAM b. Cutting bonds between NAG and NAM c. Causing cells to burst d. a and c

b. Cutting bonds between NAG and NAM

The function of the Golgi apparatus is to

a. Create proteins b. Modify proteins c. Digest proteins d. Create lipids

b. Modify proteins

Which is not part of the flagellum?

a. Hook b. Filament c. Fimbriae d. Basal Body

c. Fimbriae

Which is/are ways to detect the number/concentration of living cells?

a. Spectrophotometer b. Firefly luciferase c. Direct microscopic count d. Total weight

b. Firefly luciferase

The energy and carbon sources of a photoheterotroph are

a. The sun; CO₂ b. The sun; organic molecules c. Chemical bond energy; CO₂ d. Chemical bond energy; organic molecules

b. The sun; organic molecules

A pure culture was inoculated into a tube of solid medium and allowed to grow. Growth was only observed in a narrow range just below the surface of the agar. The microbe is:

a. An aerobe b. An anaerobe c. A facultative aerobe d. A microaerophile

d. A microaerophile

The generation time of a bacterium was measured at two different temperatures. Which results would be expected of a thermophile?

a. 220 minutes at 10°C; 20 minutes at 37°C b. No growth at 10°C; 20 minutes at 37°C c. 20 minutes at 45°C; 220 minutes at 65°C d. 220 minutes at 37°C; 20 minutes at 65°C

d. 220 minutes at 37°C; 20 minutes at 65°C

Which would be best to isolate an antibiotic resistant mutant?

a. Complex media b. Defined media c. Selective media d. Differential media

c. Selective media

Which is false about bacterial growth?

a. The bacterial growth rate measures how fast bacterial cells increase in volume b. Bacterial growth under optimal conditions occurs at an exponential rate c. Bacterial growth occurs by binary fission d. DNA must be replicated before cells divide

a. The bacterial growth rate measures how fast bacterial cells increase in volume

Which is false about the growth curve?

a. Primary metabolites are primarily produced during stationary phase b. In stationary phase, there is birth of cells c. Cells that survive prolonged decline have adaptations that make them more fit for adverse conditions d. In lag phase, the cell is making enzymes that allow it to use nutrients

a. Primary metabolites are primarily produced during stationary phase

Unlike a disinfectant, an antiseptic

a. Sanitizes objects rather than sterilizing them b. Destroys all microorganisms c. Is non-toxic enough to be used on human skin d. Requires heat to be effective

c. Is non-toxic enough to be used on human skin

The D value is defined as the time it takes to kill

a. All bacteria in a population b. All pathogens in a population c. 99.9% of bacteria in a population d. 90% of bacteria in a population

d. 90% of bacteria in a population

Ultraviolet light kills bacteria by

a. Generating heat b. Damaging DNA c. Inhibiting protein synthesis d. Damaging cytoplasmic membranes

b. Damaging DNA

Why must a scalpel, which cuts into tissues, be sterile while an endoscope, which is inserted into the colon, may safely harbor some endospores?

a. Endospores can’t germinate in the colon b. Endospores cannot typically produce serious infections c. Critical instruments only need to be sanitized d. Mucosal membranes provide a barrier to the spread of bacteria

d. Mucosal membranes provide a barrier to the spread of bacteria

Why does anoxygenic photosynthesis not release O₂?

a. The oxygen is reacted with a downstream product. b. Water is not the electron donor. c. Anoxygenic photosynthesizers lack an analog to photosystem II d. ATP is generated exclusively by cyclic photophosphorylation, so no electron donor is needed.

b. Water is not the electron donor.

Which is false of the bacterial electron transport chain?

a. The bacterial electron transport chain can power cell motility b. The bacterial electron transport chain lacks an analog to complex III c. The bacterial electron transport chain does not use ATP synthase d. The bacterial electron transport chain extracts more energy by aerobic respiration than by anaerobic respiration

c. The bacterial electron transport chain does not use ATP synthase

Which would NOT be an energy source for a chemolithotroph?

a. Pyruvate b. NH₃ c. Iron d. H₂

a. Pyruvate

When an inhibitor binds to an enzyme at a region other than the active site and reduces the rate of reaction, this is called

a. Feedback inhibition b. Competitive inhibition c. Enzyme poison d. Allosteric inhibition

d. Allosteric inhibition

Which correctly describes the catabolic process of fatty acids?

a. The fatty acids are broken into acetyl units and broken down in the TCA cycle. b. Acetyl units from the TCA cycle are used to build up fatty acids. c. The fatty acids are degraded in the pentose phosphate pathway. d. The fatty acids are built up from pentose phosphate pathway intermediates.

a. The fatty acids are broken into acetyl units and broken down in the TCA cycle.

In the TCA cycle, the carbon atoms contained in acetate are converted into

a. Lactic acid b. CO₂ c. Glucose d. Glycerol

b. CO₂

Ribose-5-phosphate, used to make nucleotides, is produced in which of the central metabolic pathways?

a. Glycolysis b. Pentose phosphate pathway c. Transition step d. TCA cycle

b. Pentose phosphate pathway

Which is not a possible product of fermentation? a. Propionic acid b. Ethanol c. Lactic acid d. Pyruvate

d. Pyruvate

There is enough energy in the 2 NADH produced in glycolysis to make how many units of ATP?

a. 2 b. 4 c. 6 d. 12

c. 6

The gel-like material that fills the space between the cytoplasmic membrane and the outer membrane of some bacteria

Periplasm

A non-living infectious agent consisting only of RNA

Viroid

A non-living infectious agent consisting only of protein

Prion

An extraordinarily resistant dormant cell produced by some bacteria

Endospore

A distinct, thick, gelatinous material that surrounds some microorganisms

Capsule

Extrachromosomal DNA molecule that replicates independently of the chromosome

Plasmid

The highest level in classification above kingdom

Domain

Movement of a cell towards or away from a certain chemical in the environment

Chemotaxis

A culture medium with an ingredient that certain microorganisms change in a recognizable way

Differential Medium

A chemical that destroys all microbes

Sterilant

Polymer-encased community of microorganisms

Biofilm

Brief heat treatment that reduces the number of spoilage organisms and destroys disease-causing microbes

Pasteurization

A culture medium that contains protein digests, extracts, or other ingredients that vary in their chemical composition

Complex Medium

Metabolic process that stops short of oxidizing glucose completely

Fermentation

Biosynthesis

Anabolism

Disinfectant non-toxic enough to use on skin

Antiseptic

Processes that harvest energy released during the breakdown of molecules such as glucose

Catabolism