bio 226 duwel exam 1 questions with verified
answers
"Bonus" genes that may be helpful for bacteria to survive in certain
environments are often found on small, circular extrachromosoaml
DNA known as: Ans✓✓✓ Plasmids
A decrease in the pH of the medium would be expected to
_______________ chemiosmosis? Ans✓✓✓ increase
A number of colorless colonies appear on a plate of MacConkey's agar
after streaking a stool sample. What is your interpretation? Ans✓✓✓ A
fecal pathogen is suspected and needs to be further identified.
A strictly fermentative bacterium produces energy in the form of ATP
Ans✓✓✓ By glycolysis only.
According to the chemiosmotic mechanism, ATP is generated when
Ans✓✓✓ Protons are moved across a membrane.
After performing the Gram stain procedure you realize that you
decolorized with water instead of 95% EtOH. What color would the cells
appear under the microscope when observed? Ans✓✓✓ Both Gram (+)
and (-) cells would be purple.
, All of the following are direct methods to measure microbial growth
except Ans✓✓✓ Measuring glucose consumption
An aerotolerant anaerobe growing in a tube of Thioglycollate media
would be expected to be found where in the tube? Ans✓✓✓ Evenly
throughout the tube.
An overnight culture is serially diluted and then plated on BHI agar. You
do five 1:10 dilutions and then plate 1 ml of bacteria from each dilution
tube. The first and second plates are "TNC". The third plate has 1000
colonies counted, the fourth plate has 93 colony forming units and the
fifth plate has 15 colonies. What is the titer? Ans✓✓✓ 93 x 10,000
CFU/ml
At which temperature would a mesophile be at its optimal growth rate?
Ans✓✓✓ 37 degrees C
Bacteria that look like "comma" curved rods are called: Ans✓✓✓
Vibrios
Bacterial populations die at a constant logarithmic rate, therefore a one
log decrease would result in what % of the population killed? Ans✓✓✓
90%
answers
"Bonus" genes that may be helpful for bacteria to survive in certain
environments are often found on small, circular extrachromosoaml
DNA known as: Ans✓✓✓ Plasmids
A decrease in the pH of the medium would be expected to
_______________ chemiosmosis? Ans✓✓✓ increase
A number of colorless colonies appear on a plate of MacConkey's agar
after streaking a stool sample. What is your interpretation? Ans✓✓✓ A
fecal pathogen is suspected and needs to be further identified.
A strictly fermentative bacterium produces energy in the form of ATP
Ans✓✓✓ By glycolysis only.
According to the chemiosmotic mechanism, ATP is generated when
Ans✓✓✓ Protons are moved across a membrane.
After performing the Gram stain procedure you realize that you
decolorized with water instead of 95% EtOH. What color would the cells
appear under the microscope when observed? Ans✓✓✓ Both Gram (+)
and (-) cells would be purple.
, All of the following are direct methods to measure microbial growth
except Ans✓✓✓ Measuring glucose consumption
An aerotolerant anaerobe growing in a tube of Thioglycollate media
would be expected to be found where in the tube? Ans✓✓✓ Evenly
throughout the tube.
An overnight culture is serially diluted and then plated on BHI agar. You
do five 1:10 dilutions and then plate 1 ml of bacteria from each dilution
tube. The first and second plates are "TNC". The third plate has 1000
colonies counted, the fourth plate has 93 colony forming units and the
fifth plate has 15 colonies. What is the titer? Ans✓✓✓ 93 x 10,000
CFU/ml
At which temperature would a mesophile be at its optimal growth rate?
Ans✓✓✓ 37 degrees C
Bacteria that look like "comma" curved rods are called: Ans✓✓✓
Vibrios
Bacterial populations die at a constant logarithmic rate, therefore a one
log decrease would result in what % of the population killed? Ans✓✓✓
90%
