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BSCI330 Final Exam Questions With Complete
Solutions 2025
In reference to the genesis of ribosomes in a human cell:
Describe the steps (including the sites in nucleus)
that result in the production of each of the four rRNAs in
a ribosome. - ....ANSWER ....✔✔ In the nucleolus:
45S precursor rRNA molecules are transcribed off their
rRNA genes.
Each 45S rRNA undergoes several chemical
modifications (methylations of some nucleotide sugars
and isomerization of many uridines) then cleaved into
fragments that yield three of the RNAs found
in a ribosome: 18S, 5.8S, and 28S.
In the nucleus, but not necessarily in the nucleolus: The 5S
rRNA is transcribed from genes
separate from those coding the 45S rRNA
Outline the steps by which a protein (cargo) in the
nucleus gets exported to the cytoplasm and how the
transport machinery proteins return to the nucleus. Be
sure to include all proteins involved, the energy source,
and the release of the cargo in the cytoplasm. You may
,2|Page
use a labeled diagram. - ....ANSWER ....✔✔ 1. A
protein to be exported would contain a nuclear export
signal.
2. The cargo binds to a nuclear export receptor (or
Exportin) and to Ran-GTP.
3. The complex passes through a nuclear pore complex
to the cytoplasmic face of the nuclear
envelope.
4. In the cytoplasm, Ran-GAP causes the hydrolysis of
Ran-GTP to Ran-GDP. This leads to the
dissociation of the complex, thus the delivery of the
cargo to the cytoplasm.
5. The free export receptor (or Exportin) moves back
into the nucleus through a pore complex.
6. Ran-GDP in the cytoplasm binds to a Ran-GDP
receptor for movement back into the nucleus
through a nuclear pore complex.
7. In the nucleus Ran-GEF causes the exchange of the
GDP on Ran-GDP to a GT P, regenerating
Ran-GTP.
Summarize a study discussed in lecture showing that
proteins could pass from the cytoplasm into the nucleus
through nuclear pore complexes by indicating:
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A. The cells used in the study.
B. The protein used
C. With one sentence, how the protein molecules were
labeled for microscopy.
D. How and where the protein molecules were
introduced into cells (with just on sentence)
E. After the introduction of the protein into cells, how the
cells were treated and analyzed (two or three
sentences).
F. A typical result from the study with a labeled
diagram
G. Yes or No if you expect the results would have been
different had the analyses been done with the 5S rRNA;
explain why with one sentence. - ....ANSWER ....✔✔
A. Frog oocytes
B. Nucleoplasmin
C. The protein molecules were conjugated with colloidal
gold particles
D. The gold labeled protein molecules were injected into
the cytoplasm of each cell
E. After injection, each cell was incubated for certain
period then fixed and prepared for examination by
electron microscopy.
F. Electron micrograph showing gold-labeled
nucleoplasmin
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passing into the nucleus from the cytoplasm through the
pore complexes of the nuclear envelope.
G. Yes. The 5S rRNA molecules exit the nucleus (not
enter) as after being incorporated into the large
ribosome subunits.
T4 bacteriophage - ....ANSWER ....✔✔ a kind of virus
that infects only bacterial cells of the E. Coli species; has
six tail fibers
Adenovirus - ....ANSWER ....✔✔ Name the DNA virus:
• Linear dsDNA; naked; replicates in the nucleus
human immunodeficiency virus (HIV) - ....ANSWER
....✔✔ Acquired immunodeficiency syndrome (AIDS) is
caused by HIV, which damages the cells in the body's
immune system so that the body is unable to fight
infection or certain cancers.
Gortel and Grendel - ....ANSWER ....✔✔ First to
suggest that plasma membranes of red
blood cells consisted of lipid bilayers.
BSCI330 Final Exam Questions With Complete
Solutions 2025
In reference to the genesis of ribosomes in a human cell:
Describe the steps (including the sites in nucleus)
that result in the production of each of the four rRNAs in
a ribosome. - ....ANSWER ....✔✔ In the nucleolus:
45S precursor rRNA molecules are transcribed off their
rRNA genes.
Each 45S rRNA undergoes several chemical
modifications (methylations of some nucleotide sugars
and isomerization of many uridines) then cleaved into
fragments that yield three of the RNAs found
in a ribosome: 18S, 5.8S, and 28S.
In the nucleus, but not necessarily in the nucleolus: The 5S
rRNA is transcribed from genes
separate from those coding the 45S rRNA
Outline the steps by which a protein (cargo) in the
nucleus gets exported to the cytoplasm and how the
transport machinery proteins return to the nucleus. Be
sure to include all proteins involved, the energy source,
and the release of the cargo in the cytoplasm. You may
,2|Page
use a labeled diagram. - ....ANSWER ....✔✔ 1. A
protein to be exported would contain a nuclear export
signal.
2. The cargo binds to a nuclear export receptor (or
Exportin) and to Ran-GTP.
3. The complex passes through a nuclear pore complex
to the cytoplasmic face of the nuclear
envelope.
4. In the cytoplasm, Ran-GAP causes the hydrolysis of
Ran-GTP to Ran-GDP. This leads to the
dissociation of the complex, thus the delivery of the
cargo to the cytoplasm.
5. The free export receptor (or Exportin) moves back
into the nucleus through a pore complex.
6. Ran-GDP in the cytoplasm binds to a Ran-GDP
receptor for movement back into the nucleus
through a nuclear pore complex.
7. In the nucleus Ran-GEF causes the exchange of the
GDP on Ran-GDP to a GT P, regenerating
Ran-GTP.
Summarize a study discussed in lecture showing that
proteins could pass from the cytoplasm into the nucleus
through nuclear pore complexes by indicating:
,3|Page
A. The cells used in the study.
B. The protein used
C. With one sentence, how the protein molecules were
labeled for microscopy.
D. How and where the protein molecules were
introduced into cells (with just on sentence)
E. After the introduction of the protein into cells, how the
cells were treated and analyzed (two or three
sentences).
F. A typical result from the study with a labeled
diagram
G. Yes or No if you expect the results would have been
different had the analyses been done with the 5S rRNA;
explain why with one sentence. - ....ANSWER ....✔✔
A. Frog oocytes
B. Nucleoplasmin
C. The protein molecules were conjugated with colloidal
gold particles
D. The gold labeled protein molecules were injected into
the cytoplasm of each cell
E. After injection, each cell was incubated for certain
period then fixed and prepared for examination by
electron microscopy.
F. Electron micrograph showing gold-labeled
nucleoplasmin
, 4|Page
passing into the nucleus from the cytoplasm through the
pore complexes of the nuclear envelope.
G. Yes. The 5S rRNA molecules exit the nucleus (not
enter) as after being incorporated into the large
ribosome subunits.
T4 bacteriophage - ....ANSWER ....✔✔ a kind of virus
that infects only bacterial cells of the E. Coli species; has
six tail fibers
Adenovirus - ....ANSWER ....✔✔ Name the DNA virus:
• Linear dsDNA; naked; replicates in the nucleus
human immunodeficiency virus (HIV) - ....ANSWER
....✔✔ Acquired immunodeficiency syndrome (AIDS) is
caused by HIV, which damages the cells in the body's
immune system so that the body is unable to fight
infection or certain cancers.
Gortel and Grendel - ....ANSWER ....✔✔ First to
suggest that plasma membranes of red
blood cells consisted of lipid bilayers.
