rI
1
l
I
I
I
.l
I
B[OL265 Exam 3
The distinct characteristics of different cell tlpes in a multicellular organism result mainly from the
diflerential regulation of the _.
A) transcription of genes transcribed by RNA polymerase II.
B) transcriptionofhousekeepinggenes.
C) proteins that dtectly bind the TATA box of eukaryotic genes.
D), replication ofspecific genes.
) The human genome encodes about 21,000 protein-coding genes. Approximately how many such genes
does the typical differentiated human cell express at any one time?
A) between 5000 and 15,000
B) less than 2100
C) between 18,900 and 21,000-at least 90% of the genes
D) 21,0OG-all of them
J. Which of the following is not a good example of a housekeeping protein?
A) hemoglobin
B) ATP synthase
C) DNA repair enzymes
D) histones
4. Which of the following statements about differentiated cells is true?
A) Some of the proteins found in differentiated cells are found in all cells of a multicellular organism.
B) Cells of distinct t)?es express nonoverlapping sets of transcription factors.
C) Once a cell has differentiated, it can no longer change its gene expression.
D) Once a cell has differentiated, it will no longer need to transcribe RNA.
5. Investigators performed nuclear transplant experiments to determine whether DNA is altered irreversibly
during development. Which of the following statements about these experiments is true?
A) Although nuclear transplantation has been successful in producing embryos in some mammals with
the use of foster mothers, evidence of DNA alterations during differentiation has not been obtained
for plants.
B) Because the donor nucleus is taken from an adult animal, the chromosomes from the nucleus urust
undergo recombination with the DNA in the egg for successful development to occur.
C) The embryo that develops from the nuclear transplant experiment is genetically identical to the
donor of the nucleus.
D) The meiotic spindle of the egg must interact with the chromosomes of the injected nuclei for
successful nuclear transplantation to occur.
Page I
, Use the following to answer questions 6-9:
You are interested in examining the Ps/gene. It is known that Psf is normally produced when cells are exposed to high levels of both
calcium (Ca*) and magnesium (Mg'*). MetA, MetB, and MetC are important for binding to the promoter of the Ps/gene and are
involved in regulating its transcription. MetA binds to the "A" site in the promoter region, MetB to the "B" site, and MetC to the "C"
site. You create binding-site mutations in the A, B, and C sites and observe what happens to transcription of the Py'gene. Your results
are summarized in Table Q8-17.
Transcription in the presence of Ca2* andlor Mgz+ .t'
No Ca2* with with with ca2+
Binding sites present or Mgz* Ca2* Mg'* and Mg2*
4 u"d 4oI\'
A, B, and C ++
A only
B only
C only
A and B only
A and C only
B and C only
For this table:
-+ =- no transcription of Pst
low level of transcription of Psf, and
++ = high levels of transcription of Psf.
Table Q8-17
6. Which of the following proteins are likely to act as gene activators?
A) MetB only
B) MetC only
C) Both MetA and MetC
D) MetA only
7. Which of the following proteins are likely to act as gene repressors?
A) MetB only
B) Both MetA and MetC
C) MetA only
D) MetC only
8. Which kanscription factors are normally bound to the Ps/promoter in the presence of Mg2* only?
A) MetA, MetB, andMetC
B) none
C) MetAonly
D) MetA and Met B
9. Which transcription factors are normally bound to the Ps/promoter in the presence of both Mg2* and
Ca2*?
A) MetA, MetB, andMetC
B) MetAandMetC
C) MetAandMetB
D) MetB andMetC
Page2
1
l
I
I
I
.l
I
B[OL265 Exam 3
The distinct characteristics of different cell tlpes in a multicellular organism result mainly from the
diflerential regulation of the _.
A) transcription of genes transcribed by RNA polymerase II.
B) transcriptionofhousekeepinggenes.
C) proteins that dtectly bind the TATA box of eukaryotic genes.
D), replication ofspecific genes.
) The human genome encodes about 21,000 protein-coding genes. Approximately how many such genes
does the typical differentiated human cell express at any one time?
A) between 5000 and 15,000
B) less than 2100
C) between 18,900 and 21,000-at least 90% of the genes
D) 21,0OG-all of them
J. Which of the following is not a good example of a housekeeping protein?
A) hemoglobin
B) ATP synthase
C) DNA repair enzymes
D) histones
4. Which of the following statements about differentiated cells is true?
A) Some of the proteins found in differentiated cells are found in all cells of a multicellular organism.
B) Cells of distinct t)?es express nonoverlapping sets of transcription factors.
C) Once a cell has differentiated, it can no longer change its gene expression.
D) Once a cell has differentiated, it will no longer need to transcribe RNA.
5. Investigators performed nuclear transplant experiments to determine whether DNA is altered irreversibly
during development. Which of the following statements about these experiments is true?
A) Although nuclear transplantation has been successful in producing embryos in some mammals with
the use of foster mothers, evidence of DNA alterations during differentiation has not been obtained
for plants.
B) Because the donor nucleus is taken from an adult animal, the chromosomes from the nucleus urust
undergo recombination with the DNA in the egg for successful development to occur.
C) The embryo that develops from the nuclear transplant experiment is genetically identical to the
donor of the nucleus.
D) The meiotic spindle of the egg must interact with the chromosomes of the injected nuclei for
successful nuclear transplantation to occur.
Page I
, Use the following to answer questions 6-9:
You are interested in examining the Ps/gene. It is known that Psf is normally produced when cells are exposed to high levels of both
calcium (Ca*) and magnesium (Mg'*). MetA, MetB, and MetC are important for binding to the promoter of the Ps/gene and are
involved in regulating its transcription. MetA binds to the "A" site in the promoter region, MetB to the "B" site, and MetC to the "C"
site. You create binding-site mutations in the A, B, and C sites and observe what happens to transcription of the Py'gene. Your results
are summarized in Table Q8-17.
Transcription in the presence of Ca2* andlor Mgz+ .t'
No Ca2* with with with ca2+
Binding sites present or Mgz* Ca2* Mg'* and Mg2*
4 u"d 4oI\'
A, B, and C ++
A only
B only
C only
A and B only
A and C only
B and C only
For this table:
-+ =- no transcription of Pst
low level of transcription of Psf, and
++ = high levels of transcription of Psf.
Table Q8-17
6. Which of the following proteins are likely to act as gene activators?
A) MetB only
B) MetC only
C) Both MetA and MetC
D) MetA only
7. Which of the following proteins are likely to act as gene repressors?
A) MetB only
B) Both MetA and MetC
C) MetA only
D) MetC only
8. Which kanscription factors are normally bound to the Ps/promoter in the presence of Mg2* only?
A) MetA, MetB, andMetC
B) none
C) MetAonly
D) MetA and Met B
9. Which transcription factors are normally bound to the Ps/promoter in the presence of both Mg2* and
Ca2*?
A) MetA, MetB, andMetC
B) MetAandMetC
C) MetAandMetB
D) MetB andMetC
Page2
