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Flashcards in TBL 4 Deck (33)
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1
Q

What is the study of gene regulatory mechanisms which do not directly involve the DNA sequence?

A

Epigenetics

2
Q

The effect of methylation in CpG islands on gene regulation is usually:

A

Silencing

3
Q

The five epigenetic mechanisms are:

A
DNA methylation
Histone modification
ATP-Dependent chromatin remodeling
Histone variants
Noncoding RNA
4
Q

The effect of histone acetylation on DNA regulation is usually:

A

Activation

5
Q

DNA methylation is regulated by enzymes called:

A

DNA methyltransferases

6
Q

DNA methylation has ___ symmetry

A

dyad

7
Q

Following replication, methylations are copied onto the new DNA strand by:

A

maintenance methyltransferase

8
Q

In a spontaneous mutation from C to U, what repair mechanism replaces the U in DNA?

A

Base Excision Repair

9
Q

What are the two most common mutations at CpG’s?

A

C to T

G to A

10
Q

Deamination of 5’-methyl-cytosine leads to:

A

Thymine

11
Q

What gene is mutated in Rett Syndrome?

A

MeCP2

12
Q

One example of a DNA Methyltransferase used in transcriptional repression is:

A

DNMT1

13
Q

One example of a methyl-binding domain protein used for transcriptional repression is:

A

MeCP2

14
Q

What is the mechanism in which only certain genes from the allele found on a chromosome from a specific parent is:

A

Genomic imprinting

15
Q

Which allele is imprinted, the on that is turned off or left on?

A

Turned off (methylated)

16
Q

If a mutant gene is on the imprinted allele, will the disease be expressed?

A

No

17
Q

What is the disease which causes slow growin, mostly benign tumors of the parasympathetic ganglia, usually in the head/neck?

A

AD Paraganglioma (Glomus Tumors)

18
Q

Which parent is AD paragangioma inherited from? Why?

A

Father, maternally imprinted, paternally expressed

19
Q

Imprinted genes (and mutations in them) will result in a ___-of-origin effect

A

Parent

20
Q

Profound MR, happy demeanor, seizures, ataxia, and absent speech are symptoms of:

A

Angelman Syndrome

21
Q

Lack of maternal contribution of 15q11-13 is affiliated with:

A

Angelman Syndrome

22
Q

The UBE3A gene is associated with:

A

Angelman Syndrome

23
Q

Angelman Syndrome is associated wth the gene:

A

UBE3A

24
Q

Angelman syndrome is associated with a lack of paternal/maternal contribution to the ____ chromosomal region

A

Maternal, 15q11-13

25
Q

Hypotonia, failure to thrive, hyperphagia, obesity, hypopigmentation (variable), and mental retardation are symptoms of:

A

Prader-Willi Syndrome (PWS)

26
Q

Do patients of PWS have a normal karyotype?

A

Yes

27
Q

Prader-Willi Syndrome is associated with a lack of paternal/maternal contribution to the ____ chromosomal region

A

Paternal, 15q11-13

28
Q

Important genes in PWS include:

A

SNRPN and OCA2

29
Q

SNRPN is expressed from the ___ chromosome. What type of imprinting is this?

A

paternal, maternal imprinting

30
Q

UBE3A is expressed from the ___ chromosome. What type of imprinting is this?

A

maternal, paternal imprinting

31
Q

What has to occur to result in uniparental disomy?

A

Meiotic and mitotic nondisjunction resulting in trisomy rescue and a 1/3 chance of UD

32
Q

Heterodisomy must have occurred in:

A

Meiosis 1

33
Q

Isodisomy must have occurred in:

A

Meiosis 2