Microbiology Quiz 1

FtsZ, ParM, and MreB are the major cytoskeletal proteins in bacteria. Which of the following statement(s) is/are true?

A. Cytoskeletal proteins organize cell growth and cell division.

B. MreB, ParM, and FtsZ can be found in the nucleus of the cell

C. MreB, ParM, and FtsZ are cytoplasmic proteins

D. To fulfill their function, MreB, ParM, and FtsZ need to form polymers, a process that requires energy.

E. A, C, and D are correct.

F. A, B, C, and D are correct.

E

Which of the following circumstances is/are of concern in an attempt to fulfill Koch's postulates?

A. Infected animals do not show the same symptoms as infected humans.

B. The suspected pathogen is present in healthy humans.

C. an axenic (or "pure") culture cannot be obtained.

D. The suspected pathogen is only found in deceased animals

E. None of the above

A, B, C

The term "______" describes microbes that use inorganic chemicals for energy and carbon dioxide (CO2) as a carbon source.

autotroph

The rigid cell wall of bacteria is made of ____

peptidoglycan

Why is the term "microbes" more general than the term "microorganisms"?

A. It includes fungus.

B. t includes archaea.

C. It includes viruses.

D. There is no difference between these two terms.

E. The term microbes is just a more casual way of saying microorganisms.

C

____ developed a set of criteria for linking a specific microorganism to a specific disease.

Robert Koch

Archaea are most closely related to members of the domain _____

Eukarya

Nucleic acids are the most abundant macromolecules in the cell on a dry weight basis.

T/F?

False; Proteins are

What is a plasmid?

A. The structure produced when ParM proteins polymerize and separate bacterial chromosomes

B. An extrachromosomal molecule of DNA

C. Any large membrane-enclosed particle inside a bacterium

D. Magnetite-containing particles that arrange themselves in the middle of a bacterium

E. The area of the plasma membrane where the Z-ring forms for cell division

B

Which best describes the chemical structure of the plasma membrane in bacteria?

A. A bilayer of phospholipids

B. A bilayer of phospholipids with sterols

C. A monolayer of phospholipids

D. A trilayer of phospholipids

E. A monolayer of phospholipids with sterols

A

Within a population of E. coli cells, you frequently observe rod-shaped cells that are significantly larger than the rest. This species is not known to be pleomorphic. Which is the most likely explanation for your observation?

A. Cells are different because nutritional needs are not being met.

B. Cells have lost their cell walls.

C. Cells are at different stages of growth before binary fission.

D. Cells have lost their plasma membranes.

E. Cells are contaminated with Staphylococcus.

C

Yesterday, you inoculated two separate overnight cultures of Escherichia coli and Staphylococcus aureus, respectively. Today in the morning, you realize that you forgot to label the two cultures. Your lab instructor suggests to compare the two cultures under the microscope and to identify the cultures by carrying out the Gram-stain procedure. Which of the following statements is NOT true?

A. Staphylococcus aureus has a spherical morphology and forms cluster, while Escherichia coli has a rod-shaped morphology. After the Gram staining procedure, Staphylococcus aureus will remain purple while Escherichia coli will appear pink.

B. Both species display spherical morphology and form cluster. After the Gram staining procedure, Staphylococcus aureus will appear pink while Escherichia coli remains purple.

C. Gram staining procedure will lead to purple color in gram-positive bacteria due to the thick cell wall.

D. The Alcohol is used during the Gram-staining procedure to stabilize the crystal violet in gram-negative bacteria.

E. B and D are not correct.

F. B, C, D are not correct.

E

To be successful, active transport of molecules across the plasma membrane requires:

A. An ABC transport system

B. Hydrolysis of adenosine triphosphate

C. Hydrolysis of adenosine diphosphate

D. The solute molecule

E. Hydrolysis of guanosine triphosphate

F. Hydrolysis of adenosine monophosphate

A, B, D