Epigenetics Flashcards

1
Q

The changes in gene expression or phenotype that are potentially heritable without altering the underlying DNA base sequence is called

A

Epigenetics

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2
Q

what coined the term epigenetics

A

Conrad Waddington

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3
Q

what molecular process lead to epigenetic changes

A

1.changes in chromatin structure altering gene expression
2. molecular mechanisms that alter chromatin structure.

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4
Q

what is the addition of methyl groups to nucleotide bases

A

DNA methylation

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5
Q

what is the most common methylation

A

methylation of cytosine to produce 5-methylcytosine

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6
Q

methylation occurs in single or both DNA strands

A

both DNA strands

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7
Q

what is a common epigenetic modification of chromatin

A

DNA methylation

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8
Q

what is responsible for the differences in the phenotypes of honeybee queens and workers

A

Epigenetics in DNA methylation

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9
Q

histone modification are on the tails or head that interact with DNA

A

tails

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10
Q

histone modification affect

A

chromatin structure and gene transcription.

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11
Q

the post-translational modification of histones are called

A

epigenetic marks / histone code

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12
Q

Post translational modifications inludes

A

addition of phosphates, methyl groups, acetyl groups, ubiquitin

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13
Q

Acetylation of histones destabilizes the chromatin which affects transcription in what way

A

increased transcription

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14
Q

deacylation affects transcription in what way

A

decreases transcription

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15
Q

what histones are associated with active transcription

A

H3 K4 Me3 AND H3 K36 Me3

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16
Q

what histones are associated with transcriptional repression

A

H3 K9 Me3 and H4 K20 Me3

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17
Q

effect of hypoacetylated lysine on transcription

A

repression

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18
Q

effect of acetylated lysine on transcription

A

activated

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19
Q

effect of methylated lysine on transcription

A

activation, elongation, repression

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20
Q

effect of methylated arginine on transcription

A

activation

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21
Q

effect of ubiquitinylated lysine on transcription

A

activation, repression

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22
Q

do single histone modifications individually determine the transcriptional activity of a gene. true/false

A

false, it is the combined presence of a multiple epigenetic marks

23
Q

explain crosstalk

A

cross talk between epigenetics such that one histone mark may affect whether additional marks occur nearby and how they finction

24
Q

why do crosstalks occur?

A

because epigenetic marks recruit enzymes and protein that modify other histone

25
Q

Epigenetic effects by

A

RNA molecules

26
Q

an interaction between two alleles that leads to a heritable change in expression of one of the alleles

A

Paramutation

27
Q

explain paramutation in corn

A

a copy of the B’ allele converts the B-I allele to B’*, which has the same phenotype as B’

28
Q

pigmentation of b1 corn locus

A

B-I B-I produces a pigmented plant
B’ B’ and B’ B* lightly pigmented

29
Q

paramutation in Kit locus in mice

A

a cross between kit+Kit+ and kit+kit t produces some kit+kit+ with phenotypes of Kit+ kit+ and kit+kit t

30
Q

life experiences, especially early in life having long-lasting effects on behavior is called

A

bahvioral epigenetics

31
Q

Effects of epigenetics

A

behavioral epigenetics
changes induced by maternal behavior
early stress in humans
in cognition
environmental chemicals

32
Q

licking and grooming of offsprings in rodents affects

A

DNA methylation

33
Q

childhood abuse leads to

A

more methylation of glucocorticoid receptor gene

34
Q

histone acetylation in mice improved

A

learning and memory in mice with a Alzheimer like disorder

35
Q

what is the effect of maternal behavior in mice

A

alters the expression of stress-response genes which makes them less fearful as adult

36
Q

what fungicide acts as an endocrine disruptot increasing DNA methylation in sperm

A

vinclozin (prevented sperm production in treated animals)

37
Q

the offsprings of males on the low protein diet has

A

increased expression of genes involved in lipid and cholesterol metabolism and differences in DNA methylation

38
Q

explain epigenetic effects in monozygotic twins

A

methylation and acetylation patterns were similar in early life but older twins are different in gene expression

39
Q

how is X inactivation a type of epigenetics

A

x inactivation results in a stabel change in gene expression that is passed on to daughter cells

40
Q

X-inactivation starts at

A

X inactivation center and spreads to the remainder of the X chromosome

41
Q

what gene on the inactive X produces an long noncoding RNA that coats the inactive X chromosome and suppress transcription

A

Xist gene

42
Q

what gene inhibits transcription of Xist on active chromosome

A

Tsix

43
Q

what gene stimulates trasncription of Xist on inactive X chromosome

A

Jpx

44
Q

what gene sustains Tsix exoression on active X, which inhibits Xist and maintains transcription

A

Xite

45
Q

stem cells are undifferentiatec cells that can generate every cell type in an organism, this property is called

A

Pluripotency

46
Q

gene expression profile during cell differentiation is

A

increasingly fixed

47
Q

the transcription factors that induce pluripotency causes

A

extensive epigenetic reprogramming which alters patterns of DNA methylation and histone modifications

48
Q

effect of reprogramming differentiated adult cells forms

A

induced pluripotent stem cells (iPCSs)

49
Q

epigenetics in genomic imprinting

A

the expression of an allele depends on whether it is inherited from male or female parents

50
Q

what is the overall pattern of chromatin modification possessed by each individual organism

A

Epigenome

51
Q

what are used to detect DNA methylation

A

restriction endonucleases
bisulfate sequencing

52
Q

waht is used to detect histone modifications

A

ChIP

53
Q

what can be used to determine the locations of 5-methylcytosines

A

bisulfate sequencing