08 Oct Microbiology Multiple Choice Questions

Microbiology Multiple Choice Questions

1)The following are all potential pitfalls of using biostimulation when trying to remove Xenobiotic X from an environment, EXCEPT:

 

a. Runoffs from this treatment causing marine dead zones

 

 b. Introduction of nutrients causing long-term ecosystem imbalance

 

c. Not having the needed microbe in the existing environmental microbiome d

 

. Introduction of a foreign microbe causing long-term ecosystem imbalance

 

2) All of the following reasons are why bacteria are excellent models for genetic research except:

 

a. They have 1 copy of their chromosomes

 

b. Their mobile genetic elements can be used to disrupt functional genes to observe phenotypic changes

 

c. They can transfer selective markers through horizontal gene transfer

 

d. They have plasmid incompatibility

 

3) There is an outbreak of a phytoplankton-lysing virus off the coast of Carlsbad. What do you expect to happen in the LONG-TERM/AFTER AWHILE? (There will be another question about short-term)

 

a. Piezophile populations will increase

 

b. Chemolithoautotroph populations will increase

 

c. Heterotroph populations will decrease

 

 d. Chemolithoautotroph populations will decrease

 

4) You have a cell culture that has underwent a viral infection. You begin the process of differential centrifugation and perform the low speed and medium speed centrifugation. You isolate the pellet after medium speed centrifugation. Which type of virus have you likely isolated at this stage?

 

a. Lytic (r we sure its lytic?) b/c after medium, there is nuclei/large organelles so it hasn’t killed the cell yet, until after ultracentrifugation)

 

b. Lysogenic

 

5) All of the following reasons are why bacteria are excellent models for genetic research except:

 

a. They can transfer selective markers through horizontal gene transfer

 

b. They have plasmid incompatibility

 

c. They have 1 copy of their chromosomes

 

d. Their mobile genetic elements can be used to disrupt functional genes to observe phenotypic changes You are growing a culture of

 

E. coli, which has a doubling time of 25 minutes. You add arginine, and the doubling time becomes 15 minutes. From this, you have enough information to determine: (AR)

 

6) You are growing a culture of E. coli, which has a doubling time of 25 minutes. You add arginine, and the doubling time becomes 15 minutes. From this, you have enough information to determine: (AR)

 

a. this strain is arginine auxotrophic

 

b. arginine is the limiting factor in the growth medium

 

c. this strain is argd. this strain is arginine prototrophic

 

 7) You have a donor cell with a plasmid carrying a transposon. You add a culture of these donor cells to recipient cells that grow slowly when there is no methionine in the media. After this combination, the recipient cells suddenly grow faster in media without methionine. What possibly happened here? (AR)

 

a. Methionine was a limiting factor until an arg+ gene was transferred

 

b. A simple transposable element carrying a met+ gene was transferred

 

c. A replicative transposon carrying a met+ gene was transferred

 

d. A replicative transposon was transferred and integrated into a met+ gene on the chromosome