12/12/12 LS23L final exam
CABANA, ELIZABETH DIZON | Help & Feedback | Logout
► Shared Server Fall 2012 Finals week
My home ► My courses ► 12FLIFESCI23L1 ► Site info ► LS23L final exam
Quiz navigation
Started on Wednesday, December 12, 2012, 10:07 AM
1 2 3 4 5 6 State Finished
7 8 9 10 11 12 Completed on Wednesday, December 12, 2012, 11:07 AM
Time taken 1 hour
13 14 15 16 17 18
Marks 37.00/40.00
19 20 21 22 23 24 Grade 92.50 out of a maximum of 100.00
25 26 27 28 29 30
Question 1 While pipetting for an experiment, your P20 shows the values 1, 2, 8 from top to bottom
31 32 33 34 35 36
Correct respectively. How much did you pipette?
37 38 39 40 Mark 1.00 out of
Show one page at a time 1.00 Select one:
Flag question a. 128 microliters
Finish review
b. 1.28 microliters
c. 0.128 microliters
d. 12.8 microliters
e. 1280 microliters
The correct answer is: 12.8 microliters
Question 2 A student picks up the P1000 pipetter turns the volume adjustment ring until the top digit reads
Correct 0, the middle digit reads 8, and the bottom digit reads 3. He then places a tip on the shaft of
Mark 1.00 out of the pipetter and aspirates an unknown liquid from a test tube, and expels the liquid into a clean
1.00 graduated cyllinder. After ejecting the tip from the P1000 and placing it on the tray, he picks up
Flag question a P200 pipetter and turns the volume adjustment ring until the top digit reads 1, the middle digit
reads 7, and the bottom digit reads 0. He then places a tip on the shaft of the pipetter and
aspirates the same unknown liquid from the same test tube, and expels the liquid into the same
graduated cylinder. The student, who did not pay attention in Lab 1, is bewildered, and then
looks at the graduated cylinder to see how much liquid total he took out of the test tube. What
is the reading on graduated cylinder?
Select one:
a. 0.85 mL
b. 0.001mL
c. 10 mL
d. 0.1 mL
e. 1 mL
The correct answer is: 1 mL
Question 3 Gel filtration determined the total size of a protein to be 230 kD. When a SDS polyacrylamide
Correct gel electrophoresis was run, there was one band at 70 kD and another at 40kD. Based on this,
Mark 1.00 out of how many subunits might make up this protein?
1.00
https://ccle.ucla.edu/mod/quiz/review.php?attempt=78149&showall=1 1/12
, 12/12/12 LS23L final exam
Flag question Select one:
a. five
b. three
c. six
d. two
e. four
The correct answer is: five
Question 4 What other property was accounted for along with shape in running proteins in the SDSPAGE
Correct lab?
Mark 1.00 out of
1.00 Select one:
Flag question a. amino acid composition
b. time
c. pH
d. size
e. error
The correct answer is: size
Question 5 A particular E. coli cell contains a lac operon that continuously breaks down lactose into
Correct glucose and galactose. What could be a possible explanation for this occurrence?
Mark 1.00 out of
1.00 Select one:
Flag question a. The operator has a mutation that does not allow the RNA polymerase to bind to it.
b. The I gene in the lac operon is mutated and does not encode for the lac repressor.
c. This particular E. coli cell does not use glucose as a viable sugar source.
d. Betagalactosidase is being inhibited by an allosteric inhibitor.
e. The lac repressor has a mutation in the lactose binding site.
The correct answer is: The I gene in the lac operon is mutated and does not encode for the lac
repressor.
Question 6 Which of the following statements about the lac operon is false?
Correct
Mark 1.00 out of Select one:
1.00
a. It is an inducible system.
Flag question
b. Binding of lactose to the operator allows for transcription of the three lac genes.
c. It regulates the production of a series of three enzymes.
d. It is normally off if glucose is present.
e. The structural genes make products that allow for lactose metabolism.
The correct answer is: Binding of lactose to the operator allows for transcription of the three lac
genes.
https://ccle.ucla.edu/mod/quiz/review.php?attempt=78149&showall=1 2/12
CABANA, ELIZABETH DIZON | Help & Feedback | Logout
► Shared Server Fall 2012 Finals week
My home ► My courses ► 12FLIFESCI23L1 ► Site info ► LS23L final exam
Quiz navigation
Started on Wednesday, December 12, 2012, 10:07 AM
1 2 3 4 5 6 State Finished
7 8 9 10 11 12 Completed on Wednesday, December 12, 2012, 11:07 AM
Time taken 1 hour
13 14 15 16 17 18
Marks 37.00/40.00
19 20 21 22 23 24 Grade 92.50 out of a maximum of 100.00
25 26 27 28 29 30
Question 1 While pipetting for an experiment, your P20 shows the values 1, 2, 8 from top to bottom
31 32 33 34 35 36
Correct respectively. How much did you pipette?
37 38 39 40 Mark 1.00 out of
Show one page at a time 1.00 Select one:
Flag question a. 128 microliters
Finish review
b. 1.28 microliters
c. 0.128 microliters
d. 12.8 microliters
e. 1280 microliters
The correct answer is: 12.8 microliters
Question 2 A student picks up the P1000 pipetter turns the volume adjustment ring until the top digit reads
Correct 0, the middle digit reads 8, and the bottom digit reads 3. He then places a tip on the shaft of
Mark 1.00 out of the pipetter and aspirates an unknown liquid from a test tube, and expels the liquid into a clean
1.00 graduated cyllinder. After ejecting the tip from the P1000 and placing it on the tray, he picks up
Flag question a P200 pipetter and turns the volume adjustment ring until the top digit reads 1, the middle digit
reads 7, and the bottom digit reads 0. He then places a tip on the shaft of the pipetter and
aspirates the same unknown liquid from the same test tube, and expels the liquid into the same
graduated cylinder. The student, who did not pay attention in Lab 1, is bewildered, and then
looks at the graduated cylinder to see how much liquid total he took out of the test tube. What
is the reading on graduated cylinder?
Select one:
a. 0.85 mL
b. 0.001mL
c. 10 mL
d. 0.1 mL
e. 1 mL
The correct answer is: 1 mL
Question 3 Gel filtration determined the total size of a protein to be 230 kD. When a SDS polyacrylamide
Correct gel electrophoresis was run, there was one band at 70 kD and another at 40kD. Based on this,
Mark 1.00 out of how many subunits might make up this protein?
1.00
https://ccle.ucla.edu/mod/quiz/review.php?attempt=78149&showall=1 1/12
, 12/12/12 LS23L final exam
Flag question Select one:
a. five
b. three
c. six
d. two
e. four
The correct answer is: five
Question 4 What other property was accounted for along with shape in running proteins in the SDSPAGE
Correct lab?
Mark 1.00 out of
1.00 Select one:
Flag question a. amino acid composition
b. time
c. pH
d. size
e. error
The correct answer is: size
Question 5 A particular E. coli cell contains a lac operon that continuously breaks down lactose into
Correct glucose and galactose. What could be a possible explanation for this occurrence?
Mark 1.00 out of
1.00 Select one:
Flag question a. The operator has a mutation that does not allow the RNA polymerase to bind to it.
b. The I gene in the lac operon is mutated and does not encode for the lac repressor.
c. This particular E. coli cell does not use glucose as a viable sugar source.
d. Betagalactosidase is being inhibited by an allosteric inhibitor.
e. The lac repressor has a mutation in the lactose binding site.
The correct answer is: The I gene in the lac operon is mutated and does not encode for the lac
repressor.
Question 6 Which of the following statements about the lac operon is false?
Correct
Mark 1.00 out of Select one:
1.00
a. It is an inducible system.
Flag question
b. Binding of lactose to the operator allows for transcription of the three lac genes.
c. It regulates the production of a series of three enzymes.
d. It is normally off if glucose is present.
e. The structural genes make products that allow for lactose metabolism.
The correct answer is: Binding of lactose to the operator allows for transcription of the three lac
genes.
https://ccle.ucla.edu/mod/quiz/review.php?attempt=78149&showall=1 2/12
