Microbio - Exam 1 Practice Test

C

A surgeon takes a brain biopsy from a patient suspected of having Creutzfeldt-Jakob Disease (a prion disease). What test could be performed in order to confirm the diagnosis that the patient is infected with a prion?

A. Perform a stain on the brain sample that shows peptidoglycan

B. Perform a molecular test to detect prion RNA
C. Perform a stain on the brain sample that shows infectious protein molecules

D. Perform a molecular test to detect prion DNA

C

You are trying to identify a newly discovered microbe and note that it's size is more than 1mm, and therefore can be seen with the naked eye. Your microbe could NOT belong to what class(es)? Check all that apply.

A. Bacteria

B. Protozoa

C. Fungi

D. Virus

A

Autotrophs differ from heterotrophs in that they

A. Do NOT require organic compounds as an energy source

B. Require organic compounds as an energy source

C. Cannot produce energy

D. Require no molecules for energy production

B

Which of the following statements are correct regarding being able to distinguish between Bacteria vs. Archaea vs. Eukarya?

A. Archaea and Eukarya (with the exception of fungi) can be distinguished from each other by determining antibiotic susceptibility

B. Bacteria and Eukarya can be distinguished from each other by the presence or absence of a membrane-bound nucleus

C. Bacteria and Archaea can be distinguished from each other by the presence or absence of a membrane-bound nucleus

D. Bacteria and Archaea can be distinguished from each other by the presence or absence of a cell wall

A

Which classes of microbes that fall under the microbial umbrella are capable of causing disease?

A. All classes of microbes under the microbial umbrella can cause disease

B. Viruses and protozoans only

C. Fungi and prions only

D. Bacteria and viruses only

C

If a bacterial cell were capable of forming an endospore, it would _______________________.

A. Be able to adhere to surfaces

B. Be able to move by propulsion

C. Be able to survive extreme heat and degradation by chemicals

D. Two of the answer choices are correct

A and C

Check all of the statements below that demonstrate an accurate comparison between Gram positive and Gram negative cells.

A. Gram positive cells are susceptible to penicillin, while Gram negative cells are not

B. Gram positive cells have two layers of peptidoglycan, while Gram negative cells only have one

C. Gram positive cells have teichoic acids, while Gram negative cells have lipopolysaccharides (LPS)

D. Gram positive cells have two membranes, while Gram negative cells only have one

C

Scientists discover a new bacteriophage in the soil at UMBC. Which of the following statements below accurately describes what they could look for in order to determine if the bacteriophage is a lytic or lysogenic phage?

A. The phages ability to inject its DNA into a bacterial host cell

B. The phages ability to assemble its parts and burst open the host cell via lysis

C. The phages ability to integrate itself into a bacterial genome and form a prophage

D. The phages ability to bind to a bacterial cell's receptors

C

You are performing the Gram stain in lab and you forget to perform the alcohol wash. What would be the outcome?

A. Both the Gram (-) and the Gram (+) cells would remain colorless, you would be able to differentiate between G (+) and G (-)

B. The Gram (-) cells would remain purple, you would be able to differentiate between G (+) and G (-)

C. Both the Gram (-) and Gram (+) cells would remain purple, you would NOT be able to differentiate between G (+) and G (-)

D. The Gram (-) cells would remain colorless, you would NOT be able to differentiate between G (+) and G (-)

D

Jose is a two year old male who is experiencing a sore throat, fever, and malaise approximately 72 hours after attending daycare where several kids have had strep throat. It is ultimately determined that Jose has caught strep throat (Streptococcus pyogenes) from one of the infected kids at his daycare. He is put on antibiotics by his pediatrician and after 48 hours no longer has a fever and is regaining his energy. During what stage of bacterial growth is the Streptococcus pyogenes in from when the pediatrician gives him the antibiotics to 48 hours later when his symptoms start to go away?

A. Lag Phase

B. Death Phase

C. Log Phase

D. Stationary Phase

C

If you wanted to develop a new drug that would target a viruses ability to perform the adsorption step of replication, which viral component would you want to the drug to target?

A. Nucleocapsid

B. Envelope

C. Spikes

D. Capsid

B and D

Check all of the answers below that correctly explain which viral classes carry additional enzymes in order to replicate in a host cell and the function of that enzyme.

A. DNA viruses require RNA polymerase which transcribes DNA to mRNA

B. Retroviruses require reverse transcriptase which transcribes (+) RNA to DNA

C. (+) RNA viruses require RNA dependent RNA polymerase which transcribes (+) RNA to (-) RNA

D. (-) RNA requires RNA dependent RNA polymerase which transcribes (-) RNA to (+) RNA

D

Bacteriophage are naked viruses (do not contain an envelope) and therefore it's DNA will enter a bacterial cell via __________ and new phage will exit a bacterial cell via ___________________.

A. Endocytosis, budding

B. Exocytosis, lysing the host cell

C. Membrane fusion, lysing the host cell

D. Injection/release, lysing the host cell

B

Antigen tests, such as ELISA's, usually detect ______________ to diagnose viral and bacterial diseases.

A. Actively growing viral particles or bacterial cells

B. Pieces of the virus or bacterial cell

C. Genetic material

D. A patient’s blood cell count

B

If you suspected a patient of being infected with a prion disease, which two key characteristics listed below would you look for?

A. A rapid increase in the severity of the patients symptoms and short incubation time since exposure

B. A gradual increase in the severity of the patients symptoms and small holes in the brain

C. A robust host immune response to neuronal loss and small holes in the brain

D. A robust host immune response to neuronal loss and short incubation time since exposure