Minot Ch4 MicroBiology

Which one of the folliwng statements about rickettsias is false? a. Diseases caused by rickettsias are arthropod-borne. b. Rickets is caused by rickettsia species c. Rickettsia species cause typhus and tuphuslike diseases d. Rickettsias have leaky membranes.

B. Rickets is caused by a Rickettsia species.

Which one of the following statements about Chlamydia is false? a. They are obligate intracellular pathogens. b. They are considered to be entergy parasites c. The diseases they cause are all arthropod-borne d. The are considered Gram-Negative Bacteria.

C The diseases they cause are all antropod-borne

The group of bacteria that lack rigid cell walls and take on irregular shape is

C. mycoplasmas

Which of the flollowing statements about cyanbacteria is false? a. Although cyanbacteria are photosynthetic, they do not produce oxygen as a result of photosynthesis b. At one time, cyanbacteria were called blue-green algae. c. Some cyanbacteria are capable of nitrogen fixation d. Some cyanbacteria are important medically because they produce toxins.

A. Although cyanbacteria are photosynthetic, they do not produce oxygen as a result of photosynthesis

most procaryotic cells reporduce by

A. Binary fission

At the end of the Gram staining procedure, Gram-positive bacteria will be

A. Blue to purple

Which of the following diseases or groups of diseases is not caused by prions? a. certain plant diseases b. chronic wasting disease of deer and elk c. Creutzfeldt-Jacob disease of humans d. "mad-cow" disease

A. Certain plant diseases

An organism that does not require oxygen, grows better in the absence of oxygen, but can survive in atmospheres containing some molecular oxygen is know as a

A. aerotolerant anarobe.

Which of the following statements about archaea is false? a. Archaea are more closely related to eucaryotes than they are to bacteria. b. Both archaea and bacteria are procaryotic organisms c. Some archaea live in extremely hot enviroments d. The cell walls of archaea contain a thicker layer of peptidoglycan than the cell walls of bacteria.

D. The cell walls of archaea contain a thicker layer of peptidoglycan than the cell walls of bacteria.

Which one of the following steps occurs during the multiplication of animal viruses, but not during the miltiplication of bacteriophages?

D. Uncoating

The cell walls of archaea contain a thicker layer of peptidoglycan than bacterial cell walls

False (archaean cell walls do not contain peptidoglycan)

Prions are infectious RNA molecules.

False (prions are infectious proteins; viroids are infectious RNA molecules)

On entering a bacterial cell, all bacteriophages immediately initiate the lytic cycle

False (temperate bacteriophages cause lysogeny)

Most viruses contain both DNA and RNA

False (they contain either DNA or RNA)

Viruses are the smallest infectious agents.

False (viroids and prions are infectious agents that are smaller than viruses)

Mycoplasmas cannot grow on artificial media.

False (yes they can)

All diseases caused by Rickettsia spp. are arthropodborne

True

HIV is an enveloped, double-stranded RNA virus.

True

Organisms in the genus Vibrio are curved bacilli.

True

Rickettsia spp. and Chlamydia spp. cannot be grown on artificial media.

True

_______________ are obligate intracellular pathogens that cause diseases such as trachoma, inclusion conjunctivitis, and urethritis

chlamydias

_______________ are photosynthetic

cyanobacteria

Rod-shaped bacteria arranged in pairs are called

diplobacilli

Spherical bacteria arranged in pairs are called

diplococci

_______________ have no cell walls

mycoplasmas

_______________ are obligate intracellular pathogens that cause diseases such as typhus and Rocky Mountain spotted fever.

rickettsias

The bacteria that cause syphilis and Lyme disease are

spirochetes

Spherical bacteria arranged in clusters are called

staphylococci

Rod-shaped bacteria arranged in chains are called

streptobacilli

Spherical bacteria arranged in chains are called

streptococci