MCB2050 Post MT Exam Questions with Correct Answers Latest Update 2025/2026
What is the specific Guanine nucleotide Exchange Factor that binds and activates Ran? -
Answers RCC1
What nuclear import/export proteins recognises & binds the classic nuclear localization signal
(NLS) on cargo proteins? - Answers Importin-a
The mesh like network of proteins distributed throughout the nucleoplasm is called _________ -
Answers nuclear matrix
What is the function of the FG nucleoporins in the NPC? - Answers to prevent the passive
diffusion of larger molecules through the NPC
Long filamentous proteins that extend from the cytoplasm ring of the NPC into the cytoplasm
are ___________ - Answers Cytoplasmic filaments
Regions w/in the nucleus where transcription factors are concentrated and where transcription
occurs are called: - Answers transcription factories
where do nuclear speckles locate? - Answers in interchromosomal channels next to
transcription factories
functions of nuclear matrix? - Answers structural role and scaffold
functions of nuclear envelope? - Answers -to separates the contents of the nucleus from the
surround cytoplasm (barrier). -provides the structural framework for the nucleus.
The disease Hutchinson-Gilford progeria syndrome is caused by point mutations in the gene
encoding i)___________ protein and characterized by ii)_______________. - Answers i) lamina A; ii)
pre-mature ageing
The protein located in the cytoplasm that promotes the hydrolysis of Ran-GTP to Ran-GDP,
maintaining low [Ran-GTP] in the cytosol is: - Answers Ran-Gap 1
The transcription of ribosomal RNA, rRNA processing and the initial assembly the ribosomal
subunits occurs in the: - Answers Nucleolus
Ran-GAP1 is a i) ___________ which functions in the ii) __________ to help maintain the [Ran-GTP]
gradient which drives nuclear transport. - Answers i) GTPase activating protein; ii) cytosol
How does RCC1 convert Ran-GDP to Ran-GTP? - Answers It exchanges the GDP molecule for a
GTP molecule on Ran
The inactive form of the G-protein Ran found in relatively low concentration in the nucleus is: -
Answers Ran-GDP
, The large family of transport receptor proteins responsible for moving macromolecules into /
out of the nucleus are called: - Answers Karyopherins
In the cytosol i) [__________] > [____________], & the reverse is true in the nucleus. This
concentration gradient is maintained in the cytosol by the accessory protein ii) ____________
which promotes the hydrolysis of Ran-GTP to Ran-GDP - Answers i) [Ran-GDP] > [Ran-GTP]; ii)
Ran-GAP1
function of nuclear envelope - Answers Regulates transport in & out of the nucleus
RCC1 is a i) _____________ which functions in the ii) ____________ to maintain the [Ran-GTP]
gradient which drives nuclear export - Answers i) GEF; ii) nucleus
The activated form of the G-Protein Ran found in high concentration in the nucleus is: - Answers
Ran-GTP
Transcription factories are found in which subdomain of the nucleus? - Answers Inter-
chromosomal channels
The specific nuclear enzyme which converts Ran-GDP to Ran-GTP maintaining high [Ran-GTP] in
the nucleus is: - Answers RCC1
function of nuclear Lamina - Answers Provides structural support for the nucleus & serves as an
attachment for chromatin and the nuclear matrix
function of nuclear Matrix - Answers Maintains overall shape of the nucleus & serves as a
scaffold for nuclear organization
___________ refers to the minimum distance that can separate two pts while still maintaining the
ability to distinguish them as separate points - Answers Resolution
What is the specific GTPase activating protein that binds & promotes the GTPase activity of Ran?
- Answers Ran-GAP 1
Put the following steps of importin B nuclear recycling in the correct order.
A) Driven by the [Ran-GTP] gradient Ran-GTP/importin-B moves back thru the NPC into the
cytoplasm
B) Importin-B is released into the cytoplasm where it will bind importin-a in preparation for
another round of nuclear import
What is the specific Guanine nucleotide Exchange Factor that binds and activates Ran? -
Answers RCC1
What nuclear import/export proteins recognises & binds the classic nuclear localization signal
(NLS) on cargo proteins? - Answers Importin-a
The mesh like network of proteins distributed throughout the nucleoplasm is called _________ -
Answers nuclear matrix
What is the function of the FG nucleoporins in the NPC? - Answers to prevent the passive
diffusion of larger molecules through the NPC
Long filamentous proteins that extend from the cytoplasm ring of the NPC into the cytoplasm
are ___________ - Answers Cytoplasmic filaments
Regions w/in the nucleus where transcription factors are concentrated and where transcription
occurs are called: - Answers transcription factories
where do nuclear speckles locate? - Answers in interchromosomal channels next to
transcription factories
functions of nuclear matrix? - Answers structural role and scaffold
functions of nuclear envelope? - Answers -to separates the contents of the nucleus from the
surround cytoplasm (barrier). -provides the structural framework for the nucleus.
The disease Hutchinson-Gilford progeria syndrome is caused by point mutations in the gene
encoding i)___________ protein and characterized by ii)_______________. - Answers i) lamina A; ii)
pre-mature ageing
The protein located in the cytoplasm that promotes the hydrolysis of Ran-GTP to Ran-GDP,
maintaining low [Ran-GTP] in the cytosol is: - Answers Ran-Gap 1
The transcription of ribosomal RNA, rRNA processing and the initial assembly the ribosomal
subunits occurs in the: - Answers Nucleolus
Ran-GAP1 is a i) ___________ which functions in the ii) __________ to help maintain the [Ran-GTP]
gradient which drives nuclear transport. - Answers i) GTPase activating protein; ii) cytosol
How does RCC1 convert Ran-GDP to Ran-GTP? - Answers It exchanges the GDP molecule for a
GTP molecule on Ran
The inactive form of the G-protein Ran found in relatively low concentration in the nucleus is: -
Answers Ran-GDP
, The large family of transport receptor proteins responsible for moving macromolecules into /
out of the nucleus are called: - Answers Karyopherins
In the cytosol i) [__________] > [____________], & the reverse is true in the nucleus. This
concentration gradient is maintained in the cytosol by the accessory protein ii) ____________
which promotes the hydrolysis of Ran-GTP to Ran-GDP - Answers i) [Ran-GDP] > [Ran-GTP]; ii)
Ran-GAP1
function of nuclear envelope - Answers Regulates transport in & out of the nucleus
RCC1 is a i) _____________ which functions in the ii) ____________ to maintain the [Ran-GTP]
gradient which drives nuclear export - Answers i) GEF; ii) nucleus
The activated form of the G-Protein Ran found in high concentration in the nucleus is: - Answers
Ran-GTP
Transcription factories are found in which subdomain of the nucleus? - Answers Inter-
chromosomal channels
The specific nuclear enzyme which converts Ran-GDP to Ran-GTP maintaining high [Ran-GTP] in
the nucleus is: - Answers RCC1
function of nuclear Lamina - Answers Provides structural support for the nucleus & serves as an
attachment for chromatin and the nuclear matrix
function of nuclear Matrix - Answers Maintains overall shape of the nucleus & serves as a
scaffold for nuclear organization
___________ refers to the minimum distance that can separate two pts while still maintaining the
ability to distinguish them as separate points - Answers Resolution
What is the specific GTPase activating protein that binds & promotes the GTPase activity of Ran?
- Answers Ran-GAP 1
Put the following steps of importin B nuclear recycling in the correct order.
A) Driven by the [Ran-GTP] gradient Ran-GTP/importin-B moves back thru the NPC into the
cytoplasm
B) Importin-B is released into the cytoplasm where it will bind importin-a in preparation for
another round of nuclear import
