Final Exam Microbiology 2420

Which of the following is (are) used to define the field of microbiology?

both the size of the organism studied and the techniques employed in the study of organisms regardless of their size

If you were setting up an experiment to disprove spontaneous generation in a liquid medium, which of the following would be essential to the experiment?

using a sterile liquid and eliminating exposure to microorganisms

Credit for the first vaccine for the prevention of human disease is generally given to:

Edward Jenner for the prevention of small pox.

Regarding Louis Pasteur's experiments with the S-neck flask, which of the following statements is TRUE?

-The possibility of contamination was removed. - Nutrients were provided.

- All preexisting microbes in the broth were killed with heat.

-Air exchange was allowed.

-All of the answers are correct.

Who of the following was the first to observe and accurately describe microorganisms?

van Leeuwenhoek

The concept that human and animal diseases are caused by microorganisms is called the

germ theory

Who of the following developed a set of criteria that could be used to establish a causative link between a particular microorganism and a particular disease?

Koch

What is the total magnification of a specimen viewed with a 10x ocular lens and a 45x objective lens?

450x

In microscopy, the term resolution

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

Bacteria that are shaped like rigid helices are

spirilla.

Which step in the Gram stain is the critical step that allows differentiation of gram-positive cells from gram-negative cells?

alcohol-acetone

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

They are sensitive to penicillin.

Cells with a relatively complex morphology that have a true membrane-delimited nucleus are called

eukaryotes.

The lipopolysaccharide (LPS) that is found in the outer membrane of gram-negative bacteria is also known as

endotoxin.

Fimbriae:

attach bacteria to various surfaces.

Which of the following is not true about capsules and slime layers?

They are required for bacteria to grow normally in culture.

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

-they are resistant to harsh environments, thus allowing survival of sporing organisms under conditions in which nonsporing organisms would not survive.

-sporing organisms are often dangerous pathogens.

-both a and b

Bacteria do not always swim aimlessly but are attracted by such nutrients such as sugar and amino acids, and are repelled by harmful substances and bacterial waste products. Movement toward chemical attractants and away from repellents is called

chemotaxis

Which of the following is useful in distinguishing between procaryotic and eucaryotic cells?

-the use of DNA for the storage of genetic information

- the presence of ribosomes for the synthesis of proteins

- the presence of membrane-delimited organelles within the cytoplasm

- all of the above

In bacterial cells, ribosomes are packed into the cytoplasmic matrix and also loosely attached to the plasma membrane. What is the function of ribosomes?

Site of protein synthesis

Which of the following microbial groups have peptidoglycan in the cell wall?

bacteria only

Cells with a relatively simple cell morphology that do not have a true membrane-delimited nucleus are called

procaryotes.

The most commonly encountered bacteria are roughly spherical. The microbiological term describing this shape is

coccus

After the primary stain has been added but before the decolorizer has been used, gram-positive organisms are stained ________ and gram-negative organisms are stained ________.

blue; blue

Which of the following could be part of a eukaryotic organism, but never a prokaryote?

plasma membrane.

Which of the following organelles evolved from a prokaryotic cell?

cell wall

The outer membrane of Gram negative cells is more permeable than the plasma membrane because

. porin proteins establish holes in the outer membrane.

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

activation energy.

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

active transport

The breakdown of larger, more complex molecules into smaller, simpler ones with the release and trapping of some energy contained within those molecules is called

catabolism

An unfavorable reaction that requires an input of energy in order to proceed is __________.

endergonic

Which of the following is (are) considered the light reaction(s) of photosynthesis?

the production of ATP and NADPH

The pentose phosphate pathway provides

ATP

NADPH.

four- and five-carbon sugars for amino acid and nucleic acid synthesis.

All of these.

Which of the following does not occur in the light-dependent reactions of photosynthesis?

Carbon dioxide is reduced

If regulatory molecules bind to specific enzymes somewhere besides at their active sites, which of the following is true?

the shape of the active sites are changedb. the substrates cannot bind to the enzymes

In the TCA cycle, two carbons in the form of __________ are added to oxaloacetate at the start of the cycle.

acetyl-CoA

Competitive inhibition can be overcome by adding excess

substrate.

The major function(s) of the TCA cycle is(are)

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

Nutrients can be concentrated from dilute sources by

active transport and group translocation.

Organisms that can use carbon dioxide as their sole or principal source of carbon are

autotrophs

Microorganisms are involved in each of the following processes EXCEPT

smog production

If you were setting up an experiment to disprove spontaneous generation in a liquid medium, which of the following would be essential to the experiment?

using a sterile liquid and eliminating exposure to microorganisms

Credit for the first vaccine for the prevention of human disease is generally given to

Edward Jenner for the prevention of small pox.

Who of the following provided the evidence needed to discredit the concept of spontaneous generation?

Pasteur

Who of the following was the first to observe and accurately describe microorganisms?

van Leeuwenhoek

The concept that human and animal diseases are caused by microorganisms is called the

germ theory.

Who of the following developed a set of criteria that could be used to establish a causative link between a particular microorganism and a particular disease?

Koch

A 30X objective and a 20X ocular produce a total magnification of

600X.

Immersion oil is used with some microscope lenses because it has the same __________ as glass.

optical density and refractive index

Bacteria that are shaped like flexible helices are

spirochetes

In the Gram-staining procedure, the mordant is

. iodine.

Gram positive cells

have multiple layers of peptidoglycan that help retain the crystal violet stain.

After the secondary stain has been added, gram-positive organisms are stained __________ and gram-negative organisms are stained __________.

blue; pink

The lipopolysaccharide (LPS) that is found in the outer membrane of gram-negative bacteria is also known as

endotoxin.

Which of the following pairs is mismatched?

centrosome - brings food into cells

In bacterial cells, ribosomes are packed into the cytoplasmic matrix and also loosely attached to the plasma membrane. What is the function of ribosomes?

Site of protein synthesis

What is the purpose of bacterial endospores?

Allow the bacterium to survive extended periods of heat or dryness.

Bacteria accomplish chemotaxis by

Making long, uninterrupted runs when conditions are good.

Which of the following is useful in distinguishing between prokaryotic and eukaryotic cells?

the presence of membrane-delimited organelles within the cytoplasm

Which of the following is not true about bacterial flagella?

They use cytoplasmic ATP as their primary energy source.

Fimbriae

attach bacteria to various surfaces.

Cells with a relatively simple cell morphology that do not have a true membrane-delimited nucleus are called

prokaryotes

The microbiological term describing a rod shaped bacterial cell is

bacillus

Cells with a relatively complex morphology that have a true membrane-delimited nucleus are called

eukaryotes

The movement of molecules across a membrane from an area of lower concentration to an area of higher concentration with the expenditure of energy is called

active transport.

Which of the following organelles evolved from a prokaryotic cell?

mitochondrion

Plasmids are important to the genetics of many bacteria. This is because

-they are inherited from one generation to the next.

-they may carry genes that give their host a selective advantage.

-they can render bacteria drug-resistant.

-All of the above.

Enzymes catalyze a reaction by

decreasing the amount of activation energy needed to drive the reaction

Which of the following could be part of a eukaryotic organism, but never a prokaryote?

cilia

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

. anabolism

An unfavorable reaction that requires an input of energy in order to proceed is __________.

endergonic

The synthesis of ATP from ADP and Pi, when coupled with the exergonic enzymatic breakdown of a high-energy molecule, is called __________ phosphorylation

substrate-level

The pentose phosphate pathway provides

-ATP.

-NADPH.

-four- and five-carbon sugars for amino acid and nucleic acid synthesis.

- All of these.

Which of the following does not occur in the light-dependent reactions of photosynthesis?

Carbon dioxide is reduced

If regulatory molecules bind to specific enzymes somewhere besides at their active sites, which of the following is true?

-the shape of the active sites are changed

- the substrates cannot bind to the enzymes

- noncompetitive inhibition occurs

- the reactions that the enzymes catalyze will slow or halt

-all of the above are true

In aerobic conditions, it takes __________ sugar to produce the same amount of ATP when compared to anaerobic conditions.

less

Competitive inhibition can be overcome by adding excess

substrate

The major function(s) of the TCA cycle is(are)

both energy production and provision of carbon skeletons for biosynthesis of cell components

Which of the following is the best definition of oxidative phosphorylation?

Electrons are passed through a series of carriers to an organic compound.

Which of the following statements regarding the glycolysis pathway is FALSE

One molecule of ATP is expended.

Elements that are required in relatively large amounts by microorganisms are called

macronutrients.

When a microorganism is placed in a(n) __________ solution, water will enter into the cell and cause it to burst unless something is done to prevent this

hypotonic

If cells are grown in media containing amino acids labeled with radioactive nitrogen (15N), most of the radioactivity will be found in the cells'

DNA and proteins

Microorganisms that grow best at temperatures between 45oC and 70oC are called

Thermophiles

Which of the following is an advantage of the standard plate count?

determines the number of viable cells

The total number of viable microorganisms remains constant in stationary phase because

-there is a balance between cell division and cell death

-there is a cessation of cell division even though the cells may remain metabolically active

either a or b

Which of the following is NOT a direct method to measure microbial growth

metabolic activity

A culture medium on which only gram-positive organisms grow, and in which a yellow halo surrounds Staphylococcus aureus colonies, distinguishing S. aureus from other growing species, is best described as

. both a selective and differential medium.

Media containing some ingredients of unknown chemical composition are called __________ media

complex

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

. the length of time needed for a cell to divide

A gene is best defined as

a sequence of nucleotides in DNA that codes for a functional product

How many nucleotide bases are found in the code for each amino acid?

3

Which of the following is not a pyrimidine

adenine

Which nitrogenous base would only be found in RNA

uracil

When a DNA molecule is replicated, the daughter molecules contain one strand of parental DNA and one strand of newly synthesized DNA; this is called __________ replication

semiconservative

Synthesis of an enzyme coded by a repressible gene is stopped by the

accumulation of product that the enzyme catalyzes the production of

Which of the following is a product of DNA replication?

a new strand of DNA

The site on the DNA to which a repressor protein binds is the __________.

operator

Transformation

involves DNA fragments from lysed cells.

For the inducible lac operon to be turned on, the

substrate (lactose) must be absent