MB EXAM 1 PEARSON PRACTICE Q

Each of the following organisms would be considered a microbe EXCEPT

virus.

yeast.

bacterium.

mushroom.

protozoan

mushroom

The term used to describe a disease-causing microorganism is

microbe.

virus.

bacterium.

pathogen.

infection.

pathogen

A prokaryotic cell may possess each of the following cellular components EXCEPT

a cell wall.

a cell membrane.

a nucleus.

flagella.

ribosomes.

nucleus

Who is credited with first observing cells?

Robert Hooke

Anton van Leeuwenhoek

Carolus Linnaeus

Robert Koch

Louis Pasteur

Robert Hooke

Proof that a microbe could cause disease was provided by

Semmelweis.

Pasteur.

Koch.

Lister.

Wasserman.

Koch

The first step for directly linking a microbe to a specific disease according to Koch's postulates is to

culture the blood or other body fluid from a diseased animal using nutrient medium.

inject a sample of blood or other body fluid from a diseased animal into a healthy animal.

obtain a sample of blood or other body fluid from a diseased animal.

compare the blood of a sick animal to blood obtained from a healthy animal.

isolate microbes from the blood of healthy animals

obtain a sample of blood or other body fluid from a diseased animal

Penicillin was discovered by accident by

Alexander Fleming

Fungal infections are studied by

mycologists

From the list below, which would NOT be considered an emerging pathogen?

smallpox virus

Ebola virus

Lyme disease

Avian influenza

Zika virus

smallpox; numbers have decreased

Which of the following is the type of bond between molecules of water in a beaker of water?

covalent bond

hydrogen bond

ionic bond

hydrogen bond

What is the type of weak bond between the hydrogen of one molecule and the nitrogen of another molecule, where the two don't actively share an electron?

disulfide bond

hydrogen bond

covalent bond

hydrophobic bond

ionic bond

hydrogen bond

Which type of molecule contains -NH₂ (amino) groups?

nucleic acid

triglycerides

protein

carbohydrate

proteins

Which of the following statements regarding protein structure is FALSE?

The primary structure is formed by covalent bonding between amino acid subunits.

Secondary structures are formed only from hydrogen bonds.

Tertiary structures are formed only from covalent bonds.

Quaternary structures involved multiple polypeptides.

“Tertiary structures are formed only from covalent bonds” FALSE

Which molecule is composed of a chain of amino acids?

nucleic acid

lipid

protein

carbohydrate

protein

A dehydration synthesis reaction between glucose (C₆H₁₂O₆) and fructose (C₆H₁₂O₆) produces a molecule of sucrose (C₁₂H₂₂O₁₁). Why don't the two individual molecular formulae add up to the same number of atoms in the sucrose product?

In a dehydration reaction, a water molecule (H2O) is removed from the final molecule formed.

In a dehydration reaction, a water molecule (H2O) is added to the final molecule formed.

Hydrogen must be burned/consumed during the reaction.

Oxygen must be burned/consumed during the reaction.

In a dehydration reaction, a water molecule (H₂O) is removed from the final molecule formed.

Which microscope is used to observe a specimen that emits light when illuminated with an ultraviolet light?

compound light microscope

phase-contrast microscope

fluorescence microscope

darkfield microscope

electron microscope

fluorescence microscope

The capsules and flagella of bacteria can be observed in gram-stained smears.

True

False

False

You have isolated a motile, gram-positive cell with no visible nucleus. You can safely assume that the cell

has a mitochondrion.

lives in an extreme environment.

has 9 pairs + 2 flagella.

has a cell wall.

has cilia.

Most likely a bacteria —> cell wall

Antibiotics that target cell wall synthesis ultimately cause bacterial cell death as a result of

osmotic lysis.

inhibition of molecular transport.

plasmolysis.

cell shrinkage.

decreased synthesis of plasma membrane.

osmotic lysis

Most bacteria reproduce by

fragmentation.

binary fission.

budding.

mitosis.

aerial hyphae.

binary fission

Which of the following is the best definition of generation time?

the length of time needed for lag phase

the time needed for nuclear division

the minimum rate of doubling

the length of time needed for a cell to divide

the duration of log phase

the length of time needed for a cell to divide

Which physician is first associated with vaccination?

Ehrlich

Escherich

Jenner

Lister

Koch

Jenner (smallpox)

Which of the following statements about biofilms is FALSE?

Biofilms in your body protect mucous membranes from harmful microbes.

Biofilms in pipes can block the flow of water.

Biofilms on medical devices cause infections.

Compared to free-living bacteria, biofilms are more sensitive to antibiotics.

Biofilms on rocks provide food for animal life.

Compared to free-living bacteria, biofilms are more sensitive to antibiotics.

What is the type of strong chemical bond between carbon, hydrogen, and oxygen atoms in a single organic molecule?

ionic bond

covalent bond

hydrogen bond

covalent bond

Identify the following reaction: Lactose + H₂O → Glucose + Galactose

dehydration synthesis reaction

hydrolysis reaction

exchange reaction

reversible reaction

ionic reaction

Hydrolysis (addition of water)

Which microscope uses visible light?

scanning acoustic microscope

differential interference contrast microscope

scanning electron microscope

fluorescence microscope

confocal microscope

differential interference contrast microscope

Which microscope is used to see intracellular detail in a living cell?

two-photon microscope

atomic force microscope

transmission electron microscope

brightfield microscope

fluorescence microscope

two-photon microscope

In microscopy, the term resolution

is the same as the total magnification of a specimen.

is only observed in stained specimens.

refers to the ability to distinguish fine structure and detail in a specimen.

is improved when longer wavelengths of light are employed.

refers to magnification when using the electron microscope.

refers to the ability to distinguish fine structure and detail in a specimen.

In a completed Gram stain, gram-negative bacteria are colorless.

True

False

False, they are pink

In a completed Gram stain, gram-positive bacteria are purple.

True

False

True

Which of the following statements is INCORRECT regarding prokaryotic cells?

They typically have a circular chromosome.

Their DNA is not enclosed within a membrane.

They reproduce by binary fission.

They lack membrane-enclosed organelles.

They lack a plasma membrane.

They lack a plasma membrane.

Prokaryotes lack organelles.

True

False

True

The cell walls of bacteria are responsible for the shape of the bacteria and the difference in the Gram stain reaction.

True

False

True

Which of the following statements about gram-negative cell walls is FALSE?

They have an extra outer layer composed of lipoproteins, lipopolysaccharides, and phospholipids.

Their Gram reaction is due to the outer membrane.

They are sensitive to penicillin.

They are toxic to humans.

They protect the cell in a hypotonic environment.

They are sensitive to penicillin.

Which of the following is NOT a typical characteristic of most bacterial plasma membranes?

site of energy production

composed of a phospholipid bilayer

contains proteins

is selectively permeable

contains cholesterol

contains cholesterol

Which of the following statements is TRUE?

Endospores are easily stained in a Gram stain.

A cell produces one endospore and keeps growing.

Endospores are for reproduction.

Endospores allow a cell to survive environmental changes by producing a dormant period with no growth.

A cell can produce many endospores.

Endospores allow a cell to survive environmental changes by producing a dormant period with no growth.

All cells possess a cell wall.

True

False

False

Which of the following is the type of bond holding K⁺ and I^- ions in KI?

hydrogen bond

covalent bond

ionic bond

ionic

Starch, dextran, glycogen, and cellulose are polymers of

acids.

glucose.

nucleic acids.

fatty acids.

amino acids.

glucose

Which microscope is used to observe viruses and the internal structure of thinly sectioned cells?

transmission electron microscope

scanning electron microscope

darkfield microscope

brightfield microscope

fluorescence microscope

transmission electron microscope

Immersion oil is necessary when using the 100x objective on a compound light microscope

to prevent the slide from scratching the lens.

otherwise too much light is lost to refraction.

otherwise the image will be fuzzy.

otherwise too much light is lost to refraction and the image will be fuzzy.

to lubricate the objective.

otherwise too much light is lost to refraction and the image will be fuzzy.

Bacterial smears are fixed before staining to

affix the cells to the slide.

accept stain.

make their walls permeable.

make the cells visible.

affix the cells to the slide.

If you observe rod-shaped red cells after the Gram stain, you can assume their cell walls contain endotoxin.

True

False

True

Endospores are a reproductive structure.

True

False

False, designed to endure harsh conditions and ensure the organism's survival

Viruses are not considered living organisms because they

cannot reproduce by themselves.

can only be visualized using an electron microscope.

are structurally very simple.

are ubiquitous in nature.

are typically associated with disease.

cannot reproduce by themselves

Which structure protects bacteria from being phagocytized?

cell wall

capsule

cell membrane

slime layer

fimbriae

capsule

By which of the following mechanisms can a cell transport a substance from a lower to a higher concentration?

extracellular enzymes

aquaporins

facilitated diffusion

simple diffusion

active transport

active transport

The difference between simple diffusion and facilitated diffusion is that facilitated diffusion

moves materials from a higher to a lower concentration.

requires transporter proteins.

requires ATP.

moves materials from a lower to a higher concentration.

does not require ATP.

requires transporter proteins.

Microorganisms are involved in each of the following processes EXCEPT

food production.

smog production.

infection.

decomposition of organic material.

O2 production.

smog production (humans do that)

What is the type of bond between ions in salt?

ionic bond

hydrogen bond

covalent bond

ionic bond

Which of the following pairs is mismatched?

crystal violet - simple stain

acidic dye - capsule stain

nigrosin - negative stain

basic dye - negative stain

methylene blue - simple stain

basic dye - negative stain

In a hypertonic solution, a bacterial cell will typically

stay the same.

burst.

lyse.

plasmolyze.

osmolyze.

plasmolyze

Which of the following pairs of microbe classification terms and optimal growth temperatures is mismatched?

hyperthermophiles – growth at greater than 80°C

thermophile – growth at 37°C

psychrophile – growth at 15°C

mesophile – growth at 25-40°C

psychrotroph – growth at 20-30°

thermophile - growth at 37°C