ETC REVIEW UPDATED QUESTIONS AND VERIFIED
ANSWERS
what two types of lamin come from one gene? - CORRECT ANSWER✅✅✅A and C, C is shorter
what links the nuclear lamina to the cytoskeleton? - CORRECT ANSWER✅✅✅Sun/KASH complexes
how are proteins imported into the nucleus? - CORRECT ANSWER✅✅✅solube receptors recognize
nuclear localization signals and carry molecules through nuclear pores
what is the first level of DNA packaging? - CORRECT ANSWER✅✅✅the nucleosome
what molecule does DNA wrap around in a nucleosome? - CORRECT ANSWER✅✅✅histone
how are nucleosomes organized? - CORRECT ANSWER✅✅✅like beads on a string, then coiled again
what is euchromatin? - CORRECT ANSWER✅✅✅more loosely packaged and highly expressed
what is heterochromatin? - CORRECT ANSWER✅✅✅tightly packaged with low expression
how does RNA polymerase cope with the compact structure of DNA to carry out transcription? -
CORRECT ANSWER✅✅✅histone modifications and chromatin-remodeling complexes act to locally
alter chromatin structure and recruit transcriptional activators
what is the histone code? - CORRECT ANSWER✅✅✅a hypothesized code consisting of covalent
histone tail modifications; chromatin-DNA interactions are guided by combinations of histone
modifications
how can individual mutations in one proteins lead to so many different diseases in distinct tissue types?
- CORRECT ANSWER✅✅✅1. links between the nuclear lamina and the cytoskeleton may be critical
for nuclear/cellular structural integrity, especially in cells such as muscle that are subject to considerable
,stress; 2. lamin A/C and other inner NE proteins interact with chromatin, chromatin modifying proteins
and transcription factors. NE proteins may influence gene expression through organization of chromatin
structure.
Histone Code - CORRECT ANSWER✅✅✅code consisting of covalent histone tail modifications;
chromatin-DNA interactions are guided by combinations of histone modifications
HDAC inhibitors - CORRECT ANSWER✅✅✅block the ability of HDAC to condense and
transcriptionally-silence chromatin; controls gene expression
2 possible models for laminopathies causing a plethera of problems - CORRECT ANSWER✅✅✅
describe double minute chromosomes - CORRECT ANSWER✅✅✅extrachromosal chunks of
chromosomes that can replicate on their own
is gene amplification a mutation? - CORRECT ANSWER✅✅✅yes
how do tumors activate oncogenes? - CORRECT ANSWER✅✅✅create double minute chromosomes
that can replicate on their own --> --> assemble lots of ribosomes, causing cell to grow too fast (think of
myc)
what do BH3's do? - CORRECT ANSWER✅✅✅punch holes in mitochondria to release cytochrome C
what do Bcl-2's do? - CORRECT ANSWER✅✅✅keep caspases inactivated as procaspases
Knudson's Two Hit Hypothesis - CORRECT ANSWER✅✅✅in familial cases with bilateral and
multifocal retinoblastoma, an enhanced predisposition is being passed down (a single mutant copy is in
every cell) then another mutation occurs
are tumor suppression mutations dominant or recessive? - CORRECT ANSWER✅✅✅recessive
, what is a bilaminar embryo? - CORRECT ANSWER✅✅✅epiblasts and hypoblasts
what are the cell types in blastocysts? - CORRECT ANSWER✅✅✅ICM and trophoblast
how does the trophectoderm differentiate? - CORRECT ANSWER✅✅✅into cytotrophoblasts -->
syncytiotrophoblasts
into what types of cells does the trophectoderm differentiate? - CORRECT
ANSWER✅✅✅cytotrophoblast and syncytiotrophoblast
what is the syncytiotrophoblasts? - CORRECT ANSWER✅✅✅a large, multinucleated cell that invades
the endometrium
what do epiblasts form? - CORRECT ANSWER✅✅✅embryo/amnion
what does the trophectoderm form? - CORRECT ANSWER✅✅✅embryonic portion of the placenta
what is the role of selectin? - CORRECT ANSWER✅✅✅helps blastocyst attach to endometrium
what do hypoblasts form? - CORRECT ANSWER✅✅✅yolk sac
what is a common endodermal CD? - CORRECT ANSWER✅✅✅tracheoesophageal fistulas
what does the yolk sac form? - CORRECT ANSWER✅✅✅incorporated into the umbilical cord
describe gastrulation - CORRECT ANSWER✅✅✅epiblasts migrate through the primitive streak to
form the endoderm and mesoderm
how is the endoderm formed? - CORRECT ANSWER✅✅✅epiblasts migrate through the primitive
streak l
ANSWERS
what two types of lamin come from one gene? - CORRECT ANSWER✅✅✅A and C, C is shorter
what links the nuclear lamina to the cytoskeleton? - CORRECT ANSWER✅✅✅Sun/KASH complexes
how are proteins imported into the nucleus? - CORRECT ANSWER✅✅✅solube receptors recognize
nuclear localization signals and carry molecules through nuclear pores
what is the first level of DNA packaging? - CORRECT ANSWER✅✅✅the nucleosome
what molecule does DNA wrap around in a nucleosome? - CORRECT ANSWER✅✅✅histone
how are nucleosomes organized? - CORRECT ANSWER✅✅✅like beads on a string, then coiled again
what is euchromatin? - CORRECT ANSWER✅✅✅more loosely packaged and highly expressed
what is heterochromatin? - CORRECT ANSWER✅✅✅tightly packaged with low expression
how does RNA polymerase cope with the compact structure of DNA to carry out transcription? -
CORRECT ANSWER✅✅✅histone modifications and chromatin-remodeling complexes act to locally
alter chromatin structure and recruit transcriptional activators
what is the histone code? - CORRECT ANSWER✅✅✅a hypothesized code consisting of covalent
histone tail modifications; chromatin-DNA interactions are guided by combinations of histone
modifications
how can individual mutations in one proteins lead to so many different diseases in distinct tissue types?
- CORRECT ANSWER✅✅✅1. links between the nuclear lamina and the cytoskeleton may be critical
for nuclear/cellular structural integrity, especially in cells such as muscle that are subject to considerable
,stress; 2. lamin A/C and other inner NE proteins interact with chromatin, chromatin modifying proteins
and transcription factors. NE proteins may influence gene expression through organization of chromatin
structure.
Histone Code - CORRECT ANSWER✅✅✅code consisting of covalent histone tail modifications;
chromatin-DNA interactions are guided by combinations of histone modifications
HDAC inhibitors - CORRECT ANSWER✅✅✅block the ability of HDAC to condense and
transcriptionally-silence chromatin; controls gene expression
2 possible models for laminopathies causing a plethera of problems - CORRECT ANSWER✅✅✅
describe double minute chromosomes - CORRECT ANSWER✅✅✅extrachromosal chunks of
chromosomes that can replicate on their own
is gene amplification a mutation? - CORRECT ANSWER✅✅✅yes
how do tumors activate oncogenes? - CORRECT ANSWER✅✅✅create double minute chromosomes
that can replicate on their own --> --> assemble lots of ribosomes, causing cell to grow too fast (think of
myc)
what do BH3's do? - CORRECT ANSWER✅✅✅punch holes in mitochondria to release cytochrome C
what do Bcl-2's do? - CORRECT ANSWER✅✅✅keep caspases inactivated as procaspases
Knudson's Two Hit Hypothesis - CORRECT ANSWER✅✅✅in familial cases with bilateral and
multifocal retinoblastoma, an enhanced predisposition is being passed down (a single mutant copy is in
every cell) then another mutation occurs
are tumor suppression mutations dominant or recessive? - CORRECT ANSWER✅✅✅recessive
, what is a bilaminar embryo? - CORRECT ANSWER✅✅✅epiblasts and hypoblasts
what are the cell types in blastocysts? - CORRECT ANSWER✅✅✅ICM and trophoblast
how does the trophectoderm differentiate? - CORRECT ANSWER✅✅✅into cytotrophoblasts -->
syncytiotrophoblasts
into what types of cells does the trophectoderm differentiate? - CORRECT
ANSWER✅✅✅cytotrophoblast and syncytiotrophoblast
what is the syncytiotrophoblasts? - CORRECT ANSWER✅✅✅a large, multinucleated cell that invades
the endometrium
what do epiblasts form? - CORRECT ANSWER✅✅✅embryo/amnion
what does the trophectoderm form? - CORRECT ANSWER✅✅✅embryonic portion of the placenta
what is the role of selectin? - CORRECT ANSWER✅✅✅helps blastocyst attach to endometrium
what do hypoblasts form? - CORRECT ANSWER✅✅✅yolk sac
what is a common endodermal CD? - CORRECT ANSWER✅✅✅tracheoesophageal fistulas
what does the yolk sac form? - CORRECT ANSWER✅✅✅incorporated into the umbilical cord
describe gastrulation - CORRECT ANSWER✅✅✅epiblasts migrate through the primitive streak to
form the endoderm and mesoderm
how is the endoderm formed? - CORRECT ANSWER✅✅✅epiblasts migrate through the primitive
streak l
