BIOS 225 FINAL Exam - bacteria or archaea. –Answer false, also fungi.

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BIOS 225 FINAL Exam

• true or false microbiologists study a variety of organisms, but all are considered either

bacteria or archaea.–Answer false, also fungi.

• true or false the rotation of bacterial flagella is powered by ATP hydrolysis.-

–Answer false

• true or false the membrane bound structure that contains the chromo- somes of eukaryotes is

called the nucleus.–Answer true

• true or false pathogenic bacteria with capsules or slime layers are more difficult to clear by

the immune system.–Answer true

• true or false eukaryotes usually have more than one chromosome for the storage of genetic

information.–Answer true

• true or false fecal transplants have been successfully used to treat Clostrid- ioides difficile

colitis by reintroducing healthy fecal microbiota that out-com- pete the c. difficile –Answer true

• true or false a drug that disrupts a microbial function not found in animal cells usually has a

higher therapeutic index.–Answer true 1 / 3

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• true or false treatment of fungal infections is more difficult than treatment of bacterial

infections because the greater metabolic similarity between the fungi and their hosts limits the ability of a drug to have selective toxicity.–Answer true

• true or false one way in which organisms may exhibit resistance to a drug is the ability to

pump the drug out of the cell immediately after it has entered.–Answer true

• true or false gram-positive bacteria have thinner layer of peptidoglycan than gram-negative

bacteria.–Answer false

• a new microbe has been discovered in the rumen of sheep. microscopy shows no evidence

of a nuclear membrane and biochemical studies of the cell wall demonstrate the lack of peptidoglycan. metabolic studies show that this microbe generates methane. this microbe would most likely be classified in .–Answer domain Archaea.

• you are a medical microbiologist in Dallas, TX. A small population of individuals spread

throughout the city have been experiencing alarming yet similar symptoms affecting the liver that have physicians puzzled as to the etiology, although they all suspect it is a microbial in nature. what steps would you take to elucidate the organism?–Answer sample the livers from the affected patients to culture and compare organisms....grow the suspected organisms in culture....inoculate the cultured organisms into a laboratory animal and monitor for similar symptoms....culture and analyze the organism from the lab animal and determine relatedness.

• which type of locomotion is used in bacteria without flagella?

–Answer gliding

• chemotaxis is a process by which bacteria .

–Answer move toward an attractant or away from a repellent. 2 / 3

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• endospores represent a challenge to the fields of industrial and medical microbiology

because .–Answer endospores are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore forming cells would not survive, and endospore forming organisms are often dangerous pathogens.

• penicillin inhibits bacterial growth by preventing the cross-linking during peptidoglycan

synthesis. why does penicillin not inhibit growth of archaeal cells?–Answer most archaeal cells have a cell wall, but it is not composed of peptidogylcan.

• a fundamental difference between bacterial and archaeal membranes is that ?

–Answer bacterial membranes are always comprised of phospholipid bilay- ers, whereas archaeal membranes can be bilayers or monolayers.

• the organelle responsible for harvesting light as an energy source for photosynthesis is the

.–Answer chloroplast.

• the most important distinguishing feature of eukaryotes that is lacking in bacteria and

archaea is .–Answer the division of the cell into compartments that are bound by membranes.

• which type (eukarya, archaea, bacteria) has flagella that wave back and forth?

–Answer eukarya

• media containing some ingredients of unknown chemical composition are called .

–Answer complex media

• a growth medium that favors growth of some microorganisms but inhibits growth of others

is called a medium.–Answer selective medium.

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