Exam 1 Fall 2025

The development of solid culture media and pure culture techniques is attributed to:

a. Koch

b. Mechnikoff

c. Needham

d. Pasteur

a. Koch

Lister’s contribution to microbiology was associated with:

a. aseptic surgery

b. discovery of oral antiseptics

c. lyopholization

d. pasteurization

e. preservation of food

a. aseptic surgery

The concept of abiogenesis affirms:

a. the germ theory of disease

b. the principles of immunization

c. the theory of spontaneous generation

d. the theory of pinocytosis

e. none of the above is correct

c. the theory of spontaneous generation

Pasteurization consists of heating a substance at approximately 62 degrees Celsius for 30 minutes and:

a. is ineffective in ridding dairy products of all microorganisms

b. is used to produce soft drink beverages

c. was employed by the French to promote the aging process in fine wines

d. was originally developed by Central Asian tribesmen in the fermentation of koumiss

a. is ineffective of ridding dairy products of all microorganisms

Louis Pasteur made advances in microbiology by his work on:

a. disproving spontaneous generation

b. developing antibiotics

c. identifying the cell as the fundamental unit of life

d. identifying the etiological agents of chicken cholera, anthrax, and rabies disease

e. two of the above

f. all of the above

e. two of the above (A and D)

All living organisms display which of the following characteristics?

a. assimilation of nutrients and elimination the waste products of metabolism

b. irritability

c. mutability

d. reproducibility

e. two of the above are correct

f. all of the above are correct

f. all of the above are correct

Whittaker’s five-kingdom system of classification offers which of the following features?

a. It assigns viruses and viroids to the Kingdom Monera

b. It determines three distinct lines of nutrition

c. It demonstrates the differences in cellular organization among the three evolutionary advance kingdoms

d. It proposes probable evolutionary relationships among the different groups

e. More than one of the above is correct

f. All of the above are features of the system

e. More than one of the above is correct (b, c, d)

Which of the following is not a part of Whittaker’s five-kingdom system of classification?

a. Kingdom Animalia

b. Kingdom Monera

c. Kingdom Plantae

d. Kingdom Prokaryotae

e. Kingdom Protista

d. Kingdom Prokaryotae

Bacteria reproduce via binary fission that leads to the exponential expansion of the population. On the premise that a single cell gives rise to a colony of cells, how long will it take Escherichia coli (GT=30 minutes) to produce a colony of a million cells?

a. time < 8 hours

b. 8 hours < time < 12 hours

c. 12 hours < time < 18 hours

d. 18 hours < time < 24 hours

e. 24 hours < time < 36 hours

f. 36 hours < time < 48 hours

b. 8 hours < time < 12 hours

((20×30)/60=10 hours)

Prokaryotic cells are characterized by which of the following features?

i. Chromosomal distribution during replication occurs via mitotic segregation

ii. Golgi complexes are responsible for the synthesis of new cell wall material

iii. Some of the internal components of the cell are phopholipid bilayer membrane bound

iv. Structural rigidity of the cell is maintained by the peptidoglycan cell wall

a. Statements i and iii are correct

b. Statements i, iii, and iv are correct

c. Statements ii and iv are correct

d. Statement iv is correct

e. All of the above are correct

d. Statement iv is correct

Mesosomes are internal structures found in prokaryotic cells which:

a. are involved in the synthesis of new proteins

b. are folds on the cytoplasmic membrane into the cytoplasm

c. contain reserves of stored nutrients

d. serve to anchor flagella in the cytoplasm

e. manufacture slim for the bacterial capsule

b. are folds on the cytoplasmic membrane into the cytoplasm

Which of the following structures is/are not always found in the typical prokaryotic cell?

a. capsules (slime layers)

b. granules

c. inheritable genetic material

d. mesosomes

e. ribosomes

f. more than one of the above are not found in the typical prokaryotic cell

a. capsules (slime layers)

Flagella are structures that:

a. are composed of polysaccharides

b. are found in certain bacteria, protozoa, algae, and viruses

c. are more complex in eukaryotic cells than in prokaryotic cells

d. two of the above are correct

e. all of the above are correct

d. two of the above are correct (b and c)

The basic unit of bacterial measurement is the:

a. angstrom

b. micrometer

c. millimeter

d. nanometer

b. micrometer

The bacteria characterized by a very small size and pleomorphism are the:

a. mycobacteria

b. mycoplasms

c. spirochetes

d. staphylococci

e. streptococci

d. mycoplasms

Spiral-shaped bacteria occur predominantly as:

a. clusters

b. diplobacilli

c. palisades

d. sarcinae

e. single cells

e. single cells

Which of the following statements regarding bacterial capsules is/are false?

a. The capsule is a virulence factor — without it the infective capacity of the bacteria is much reduced

b. The capsule is composed of insoluble metal compounds like ferric oxide

c. The size of the capsule is related to the medium in which the bacterium is grown

d. All of the above are correct

b. The capsule is composed of insoluble metal compounds like ferric oxide

Peptidoglycan is a polymer consisting of the following chemical constituents:

a. NAG, NAM, and teichoic acid

b. NAG, lipopolysaccharides, and a peptide chain

c. NAM, lipoproteins, and teichoic acid

d. protein, teichoic acid, and diaminopomelic acid

e. NAG, NAM, and a peptide chain

e. NAG, NAM, and a peptide chain

Which of the following statements regarding gram-negative cell walls is/are true?

i. Because of their monolayered cell wall, gram-negative cell walls do not decolorize easily with organic solvents (e.g., ethyl alcohol) during the gram staining process

ii. They are less resistant to physical disruption than are gram-positive cell walls

iii. They are more susceptible to penicillin than are gram-positive cell walls

iv. They contain a lower percentage of peptidoglycans than do gram-positive cells walls

a. Statements i, ii, and iii are true

b. Statements i, iii, and iv are true

c. Statements ii and iv are true

d. Statement iv is true

e. All of the above are true

c. Statements ii and iv are true

Which of the following statements is/are true?

i. Mesosomes function in cell wall synthesis and the division of nuclear material

ii. The bacterial genome possesses one discrete chromosome

iii. The chromatinic area of the cytoplasm is rich in DNA

iv. The cytoplasmic area of the cytoplasm contains ribosomes—the site of protein biosynthesis

a. Statements i, ii, and iii are correct

b. Statements i and iii are correct

c. Statements ii and iv are correct

d. Statement iv is correct

e. All of the above are correct

e. All of the above are correct

The term spheroplast applies to a gram-negative bacterial cell which:

a. has recently undergone osmotic shock

b. is fighting off an infection by bacteriophages

c. is in the early stages of binary fission

d. is just about ready to produce a spore

e. is lacking the peptidoglycan layer from the cell wall

e. is lacking the peptidoglycan layer from the cell wall

Some of the major consequences of bacteria having a greater ratio of surface are to volume are:

a. they are capable of reproducing more rapidly than eukaryotes

b. they can metabolize compounds more rapidly than eukaryotes

c. they can more rapidly exchange of nutrients with their environment than larger eukaryotes

d. two of the above are correct

e. all of the above are correct

e. all of the above are correct

Eukaryote, Prokaryote, or Both?

photosynthesis is associated with a chloroplast

Eukaryote

Eukaryote, Prokaryote, or Both?

flagella used for motility

both

Eukaryote, Prokaryote, or Both?

cell membrane present

both

Eukaryote, Prokaryote, or Both?

ribosomes

both

Eukaryote, Prokaryote, or Both?

chromosome(s) present

both

A microorganism that derives its energy and carbon requirements from the oxidation of organic chemical compounds is called a:

a. chemoautotroph

b. chemoheterotroph

c. photoautotroph

d. photoheterotroph

b. chemoheterotroph

Which of the following statements regarding vitamins is/are true?

i. Some bacteria can synthesize their entire vitamin requirement

ii. They are inorganic compounds that must be supplied to fastidious bacteria for normal growth

iii. They are organic compounds some of which in trace amounts are essential in the formation of many coenzymes

iv. They are required in the metabolic processes of all bacteria

a. Statements i, ii, and iii are correct

b. Statements i, iii, iv are correct

c. Statements ii and iv are correct

d. Statement iv is correct

e. All of the above are correct

b. Statements i, ii, and iv are correct

Bacteria which grow best at 37 degrees C are called:

a. mesophiles

b. microaerobes

c. psychrophiles

d. thermophiles

a. mesophiles

Yeast extract is added to a peptone medium primarily to provide additional amounts of:

a. B vitamins

b. carbohydrates

c. gelatin

d. inorganic salts

e. potassium

a. B vitamins

Facultative anaerobic bacteria:

a. are obligate thermophiles

b. grow only in the presence of minute quantities of oxygen

c. respire in the presence or absence of free oxygen

d. require an excess of carbon dioxide for growth

c. respire in the presence of absence of free oxygen

Fastidious microorganisms:

a. are always anaerobic

b. are heterotrophic

c. have complex nutritional requirements

d. require a very clean environment

e. all of the above are correct

c. have complex nutritional requirements

The main form of reproduction in bacteria is:

a. budding

b. fragmentation

c. meiosis

d. sporualtion

e. transverse binary fission

e. transverse binary fission

Halobacteria (halophilic bacteria) are able to survive in areas of high pH.

a. true

b. false

b. false

Which of the following contributes to the formation of the stationary phase of the bacterial growth curve?

a. an increase in metabolic waste products

b. pH change in the culture media

c. reduction in nutrient supply

d. two of the above are correct

e. all of the above are correct

e. all of the above are correct

The optimum growth temperature range of psychrophiles is:

a. below 20C

b. between 20C and 40C

c. between 30C and 40C

d. above 45C

a. below 20C

Match the various stages of the prokaryotic cell cycle with the appropriate processes on the right with which they are associated.

LAG PHASE

a. population doubles at regular time intervals

b. exhaustion of nutrients in culture media

c. increasing cellular autolysis in the population

d. no change in population size, chemical composition change

d. no change in population size, chemical compositional change

Match the various stages of the prokaryotic cell cycle with the appropriate processes on the right with which they are associated.

LOG PHASE

a. population doubles at regular time intervals

b. exhaustion of nutrients in culture media

c. increasing cellular autolysis in the population

d. no change in population size, chemical composition change

a. population doubles at regular time intervals

Match the various stages of the prokaryotic cell cycle with the appropriate processes on the right with which they are associated.

STATIONARY PHASE

a. population doubles at regular time intervals

b. exhaustion of nutrients in culture media

c. increasing cellular autolysis in the population

d. no change in population size, chemical composition change

b. exhaustion of nutrients in culture media

Match the various stages of the prokaryotic cell cycle with the appropriate processes on the right with which they are associated.

DECLINE PHASE

a. population doubles at regular time intervals

b. exhaustion of nutrients in culture media

c. increasing cellular autolysis in the population

d. no change in population size, chemical composition change

increasing cellular autolysis in the population

Koch’s Postulates established criteria designed to demonstrate the relationship between an etiologic agent and a disease. Which of the following are included in the criteria?

a. The microorganism must be isolated from all organisms demonstrating the disease

b. The microorganism must be isolated from the diseased organism must cause disease when introduced into health organisms

The isolated microorganism must cause disease when introduced into health organisms

d. The microorganism must be re-isolated from the second host, grown, characterized and demonstrated to be the same microorganism isolated from the original host.

e. More than one of the above are correct

f. All of the above are correct

f. All of the above are correct

The Central Dogma of Molecular Biology suggests information flows from:

a. DNA to RNA to Protein

b. Protein to DNA to RNA

c. Protein to RNA to DNA

d. RNA to DNA to Protein

e. none of the above

a. DNA to RNA to Protein

The functioning of a chemoautotroph depends upon its ability to extract and use the chemical potential energy locked within the structure of organic molecules.

a. true

b. false

a. true

Microorganisms transform matter; wherby, putrefaction in the transformation of protein and fermentation is the transformation of:

a. carbohydrates

b. lipids

c. nucleic acid

d. polypeptides

e. unsaturated free fatty acids

f. More than one of the above are correct

g. All of the above are correct

a. carbohydrates