MCB 252 Exam Questions and Correct
Answers
Page 1 of 260
,Question 1
You are studying a cell line in in which one cell cycle takes approximately 24
hours. You perform FACS analysis on a population of your dividing cells. Your
cells are growing asynchronously meaning different cells are in different
stages of the cell cycle. Your FACS analysis indicates that 1/3 of your cells
have a DNA content of 2n. How long is the G1 phase in these cells?
Correct Answer
8 hours
Question 2
You are studying one type of classic cadherin. You express that cadherin in a
cell line that normally does not adhere. You connect your gene to two
different promoters, one promoter expresses 5x as much cadherin as the
other promoter. You them perform a cell adhesion assay with a mixture cells
some of which contain the gene expressing the higher level of your cadherin
and others which contain a gene that expresses a lower level of your
cadherin. What result do you expect at the end of your adhesion assay?
Correct Answer
The cells expressing the higher level of cadherin will cluster in the middle of
a ball and the cells expressing the lower level will form a layer(s)
surrounding the central ball
Question 3
Which one of the following terms most specifically describes the type of
allele of the CDC genes that Lee Hartwell isolated in order to study the cell
cycle in the bakers/brewers yeast S. cerevisiae?
Correct Answer
conditional/temperature sensitive
Page 2 of 260
,Question 4
Yo are studying a particular protein we'll call YFP (for Your Favorite Protein).
You hypothesize that YFP binds tightly to other proteins in the cell and wish
to identify those proteins. Which technique discussed in lecture will most
directly allow you to achieve your goal?
Correct Answer
a co-immunoprecipitation experiment
Question 5
Which part of dynein family members contains the ATPase?
Correct Answer
the head
Question 6
Which family of cell-cell adhesion molecules has approximately 750 family
members in humans and is thought to play a role in wiring of the human
brain?
Correct Answer
Ig-CAMs
Question 7
true/false
when one is studying yeast and plates for single cells, all cells within a given
colony are expected to be genetically identical
Correct Answer
true
Page 3 of 260
, Question 8
In lecture we discussed the fact "n" represents the haploid DNA content in an
organism (the haploid amount of DNA found in each cell of that organism)
and that 2n is the diploid DNA content. What is the DNA content in a human
cell that is in the mitotic stage of the cell cycle?
Correct Answer
4n
Question 9
what is the role of centrioles in centrosome function?
Correct Answer
microtubule organizing center
"organize" the peri-centriolar material (PCM)
Question 10
In lecture we talked about an experiment that allow us to figure out the
conformational change associated with the power stroke of dynein. In that
experiment we compared EM micrographs of dynein molecules trapped in
the pre-power stroke conformation with EM micrographs of dynein
molecules trapped in the post-power stroke conformation. What nucleotide
did we use to trap dynein motors in the pre-power stroke conformation?
Correct Answer
ADP-Vi
Question 11
true/false
dyneins and kinesins are part of the same superfamily of proteins
Correct Answer
false
Page 4 of 260
Answers
Page 1 of 260
,Question 1
You are studying a cell line in in which one cell cycle takes approximately 24
hours. You perform FACS analysis on a population of your dividing cells. Your
cells are growing asynchronously meaning different cells are in different
stages of the cell cycle. Your FACS analysis indicates that 1/3 of your cells
have a DNA content of 2n. How long is the G1 phase in these cells?
Correct Answer
8 hours
Question 2
You are studying one type of classic cadherin. You express that cadherin in a
cell line that normally does not adhere. You connect your gene to two
different promoters, one promoter expresses 5x as much cadherin as the
other promoter. You them perform a cell adhesion assay with a mixture cells
some of which contain the gene expressing the higher level of your cadherin
and others which contain a gene that expresses a lower level of your
cadherin. What result do you expect at the end of your adhesion assay?
Correct Answer
The cells expressing the higher level of cadherin will cluster in the middle of
a ball and the cells expressing the lower level will form a layer(s)
surrounding the central ball
Question 3
Which one of the following terms most specifically describes the type of
allele of the CDC genes that Lee Hartwell isolated in order to study the cell
cycle in the bakers/brewers yeast S. cerevisiae?
Correct Answer
conditional/temperature sensitive
Page 2 of 260
,Question 4
Yo are studying a particular protein we'll call YFP (for Your Favorite Protein).
You hypothesize that YFP binds tightly to other proteins in the cell and wish
to identify those proteins. Which technique discussed in lecture will most
directly allow you to achieve your goal?
Correct Answer
a co-immunoprecipitation experiment
Question 5
Which part of dynein family members contains the ATPase?
Correct Answer
the head
Question 6
Which family of cell-cell adhesion molecules has approximately 750 family
members in humans and is thought to play a role in wiring of the human
brain?
Correct Answer
Ig-CAMs
Question 7
true/false
when one is studying yeast and plates for single cells, all cells within a given
colony are expected to be genetically identical
Correct Answer
true
Page 3 of 260
, Question 8
In lecture we discussed the fact "n" represents the haploid DNA content in an
organism (the haploid amount of DNA found in each cell of that organism)
and that 2n is the diploid DNA content. What is the DNA content in a human
cell that is in the mitotic stage of the cell cycle?
Correct Answer
4n
Question 9
what is the role of centrioles in centrosome function?
Correct Answer
microtubule organizing center
"organize" the peri-centriolar material (PCM)
Question 10
In lecture we talked about an experiment that allow us to figure out the
conformational change associated with the power stroke of dynein. In that
experiment we compared EM micrographs of dynein molecules trapped in
the pre-power stroke conformation with EM micrographs of dynein
molecules trapped in the post-power stroke conformation. What nucleotide
did we use to trap dynein motors in the pre-power stroke conformation?
Correct Answer
ADP-Vi
Question 11
true/false
dyneins and kinesins are part of the same superfamily of proteins
Correct Answer
false
Page 4 of 260
