Control of gene expression

Question 1

cell types are determined by

Answer 1

differential gene expression resulting in different proteins

Question 2

basic functions for cell sustenance

Answer 2

Housekeeping

Question 3

example of a housekeeping gene

Answer 3

ribosomal proteins

Question 4

formed as DNA wraps around a histone octamer

Answer 4

nuclesome

Question 5

nucleosomes are not accessible to ______ when compared to free DNA

Answer 5

DNase I

Question 6

trasncriptionally inactive

Answer 6

heterochromatin

Question 7

transcriptionally active

Answer 7

euchromatin

Question 8

accessible to limiting amounts of DNase I

Answer 8

euchromatin

Question 9

not accessible to limiting amounts of DNAse I

Answer 9

heterochromatin

Question 10

requires chromatin structure rearrangement so that RNA polymerase may bind

Answer 10

Gene activation

Question 11

regulate chromatin organization over chromosomal domains

Answer 11

Locus control regions

Question 12

LCR example

Answer 12

all globin genes

Question 13

can alter chromatin structures

Answer 13

protein complexes

Question 14

protein complexes that can alter chromatin structure example

Answer 14

SWI-SNF

Question 15

Protein Complexes are thought to act globally to ____ mobility of ________ throughout the genome but some may target specific genes

Answer 15

Protein Complexes are thought to act globally to increase mobility of nucleosomes throughout the genome but some may target specific genes

Question 16

leads to unfolding of chromatin leading to transcritptional activation

Answer 16

histone acetylation

Question 17

histone acetylation happens in

Answer 17

lysine residues

Question 18

Many transcriptional “activators” have histone ____________ activity

Answer 18

acetyltransferase (HAT)

Question 19

Many transcriptional “repressors” are histone _________

Answer 19

deacetylases (HDAC)

Question 20

diminished gene expression

Answer 20

presence of methyl groups in promoter regions

Question 21

gene activity associated with

Answer 21

absence of methylation

Question 22

key mediator of X-inactivation

Answer 22

CpG

Question 23

____ _________ adds a methyl group to the _____carbons atom of some, but not all, cytosine residues in ____ ________

Answer 23

DNA methyltranserase adds a methyl group to the fifth carbon atom of some, but not all, cytosine residues in CpG dinucleotides

Question 24

CpG dinucleotides sequences are _______ for mutations because ______ of 5-methyl cytosine forms _____ and _____ _____ will not register this as a mutation

Answer 24

CpG dinucleotides sequences are hotspots for mutations because deamination of 5- methyl cytosine forms thymine and repair machinery will not register this as a mutation

Question 25

long CpG rich regions of DNA present in promoter regions that are actively transcribed in all cell types

Answer 25

CpG islands

Question 26

True or false: About 75% of human genes have a CpG island near their enhancers regions

Answer 26

false: About 50% of human genes have a CpG island near their promoter regions

Question 27

almost always lack methylation, regardless of whether the associated gene is active or nor

Answer 27

CpG islands

Question 28

certain genes are ______ by various signals

Answer 28

induced

Question 29

marked by protein binding to promoter or enhancer elements facilitating transcription

Answer 29

Inducible gene expression

Question 30

made in the pancreas

Answer 30

insulin

Question 31

example of hormonal induction signal

Answer 31

steroid hormones

Question 32

regulated by glucose via the PDX1 gene

Answer 32

insulin

Question 33

derived from cholesterol and are soluble in lipid membranes

Answer 33

cholesterol

Question 34

Cholesterol receptors are ______ and once bound to hormone these receptors bind to _______ or ______ elements of DNA

Answer 34

Cholesterol receptors are intracellular and once bound to hormone these receptors bind to response or enhancer elements of DNA

Question 35

used to determine differences in the mRNA population between two cell types

Answer 35

DNA microarrays

Question 36

requires mRNA isolated from two cell types

Answer 36

Microarray

Question 37

Microarray measures relative _______ in mRNA populations. Glass slides containing the ____ of interest is prepared by ________ the dsDNA so that ________ is available for complementary base pairing.

Answer 37

Microarray measures relative differences in mRNA populations. Glass slides containing the DNA of interest is prepared by denaturing the dsDNA so that ssDNA is available for complimentary base pairing

Question 38

(1) continuation of microarray. mRNA from each cell type is converted to ____ and labeled with a particular ____ probe. The ____ are pooled and _____ to the DNA on the microarray. Microscopes and computers are used to measure the amount of ________ to all of the spots on the microarray

Answer 38

mRNA from each cell type is converted to cDNA and labeled with a particular fluorescent probe. The cDNA are pooled and hybridize to the DNA on the microarray. Microscopes and computers are sued to measure the amount of hybridization to all of the spots on the microarray.

Question 39

(2) continuation of microarray. If a particular ______ is present at abnormal levels in once cell type compared to the other, the spot will not ___________________________

Answer 39

If a particular mRNA is present at abnormal levels in once cell type compared to the other, the spot will not blend of the two colors but rather on primary color

Question 40

alternative to microarray

Answer 40

RNA-seq

Question 41

RNA-seq relies on?

Answer 41

next generation sequencing to determine the composition and quantity of RNA present in a cell.

Question 42

true or false: in RNA-seq, the more sequence that appears, the more RNA is present

Answer 42

true

Question 43

excessive _______ expression is seen in multiple diseases

Answer 43

mRNA

Question 44

is used for RNA interference methods (RNAi)

Answer 44

small-interfering RNA (siRNA)

Question 45

ds-siRNA froms a

Answer 45

ribonucleoprotein complex--> RISC

Question 46

RISC binds to

Answer 46

target mRNA via complementary base pairing

Question 47

RNA interference leads to?

Answer 47

targeted destruction of "knock-down" of the bound mRNA

Question 48

can be used to "knock-out" specific genes

Answer 48

CRISPR-Cas

Question 49

programmable nuclease that can be guided to certain sites on DNA

Answer 49

Cas9

Question 50

true or false: there exists a possibility of never correcting gene defects in the future

Answer 50

false, YES WE CAN!!!

Question 51

knock-out

Answer 51

CRISPR-Cas

Question 52

Knock-down

Answer 52

RNAi