11.05.2013 Molecular Biology 4

Question 1

Accurate mechanism for replication

• repair of accidental lesion
• -is required for genetic (instability/stability)

Answer 1

stability

Question 2

(transition/transversions)substitution of a pyrimidine with a purine or vice versa.

Answer 2

tranversion

Question 3

(transition/transversions)substitution of a pyrimidine with another pyrimidine or a purine with another purine.

Answer 3

transition

Question 4

First level of repair during replication is ?

Answer 4

3’ to 5’ exonuclease activty of DNA polymerase

Question 5

T/F Distortion in the DNA helix is recognized and repaired by strand-directed mismatch repair

Answer 5

T

Question 6

Single strand breaks or nicks provide the repair signal.

-mechansims for recognizing mismatch in (e.coli/mammalian cells)

Answer 6

mammalian cells

Question 7

Both strands are methylated (dam methylase) at A in the sequence GATC.
There is a lag in the methylation of GATC sequence in the newly synthesized strand
(e.coli/mammalian cells)

Answer 7

e.coli

Question 8

(MutS/MutL) recognizes mismatched bases

Answer 8

Mut S

Question 9

(MutS/MutL)scans the DNA
for a nick to determine
the newly replicated
DNA.

Answer 9

MutL

Question 10

T/F Colon cancer phenotype has FAP stands for familial adenomatous polyposis and HNPCC stands for hereditary non-polyposis

Answer 10

T

Question 11

(transversions/frameshift) due to addition/deletion of bases

Answer 11

frameshift

Question 12

Cellular metabolic activity
Heat 
Extreme pH
Radiations
Substances in environment
--- can all case what?

Answer 12

structural alteration in DNA bases

Question 13

(spontaneous changed/UV damage) sepurination, deamination

Answer 13

spontaneous changed

Question 14

(spontaneous changed/UV damage) pyrimidine dimers

Answer 14

UV damage

Question 15

(Depurination/deamination) converst C to U

Answer 15

damination

Question 16

(Depurination/deamination) removes a purine from the nucleotide

Answer 16

depurination

Question 17

which one of the DNA bases would not undergo deamination?

guanin/cytosine/thymine

Answer 17

thymine has no amino group

Question 18

T/F mehtylated cytosine is commonly found in DNA

Answer 18

T

Question 19

Uv induces pyrimidne (A or G/ Cor T) dimers

Answer 19

C or T

Question 20

(deamination/depurination) changes the base

Answer 20

deamination

Question 21

(deamination/depurination) leads to deletion

Answer 21

depurination

Question 22

(Base excision repair/Nucleotide excision repair)Specific base is removed and repaired

Answer 22

Base excision repair

Question 23

(Base excision repair/Nucleotide excision repair)A stretch of DNA strand is removed and new strand with correct base is synthesized

Answer 23

Nucleotide excision repair

Question 24

(T/U) is an unusual base for DNA

Answer 24

U

Question 25

(RAD3/RAD6/RAD52)excision repair

Answer 25

RAD 3

Question 26

(RAD3/RAD6/RAD52) recombination-mediated repair

Answer 26

rad6

Question 27

(RAD3/RAD6/RAD52) post replication repair

Answer 27

rad 52

Question 28

yeast is best model system characterized for (prokaryote/eukaryotic) repari

Answer 28

eukaryotic

Question 29

T/F active genese are preferentially repaired

Answer 29

T

Question 30

(RAD3/RAd6) a helicase is required for repair is componenet of transcription factore associated with (DNA/RNA) polymerase

Answer 30

Rad3, RNA

Question 31

recombination , ionizing radiation | -double stand breaks are(repaired/occur)

Answer 31

occur

Question 32

Homologous end-joining (HEJ) Non-homologous end-joining (NHEJ) double strands breaks are (repaired/occur)

Answer 32

repaired

Question 33

(nonhomologous/homologous) end-joining results in loss of original sequence

Answer 33

non-homologous

Question 34

(nonhomologous/homologous) repair of double stranded breaks has no loss of sequences

Answer 34

homologous

Question 35

T/F BRCA1 and BRCA2 predispose women to breast and ovarian cancer

Answer 35

T

Question 36

(BRCA1/BRCA2) 1863 amino acids

Answer 36

BRCA1

Question 37

(BRCA1/BRCA2) 3418 amino acids

Answer 37

BRCA2

Question 38

(BRCA1/BRCA2)also involved in transcriptional regulation of genes activated in response to DNA damage.

Answer 38

BRCA1

Question 39

(BRCA1/BRCA2)Initial studies indicated involvement of BRCA1 in repairing DNA damage.

Answer 39

BRCA1

Question 40

BRCA1 and BRCA2 interact with other proteins that activate repair of double strand breaks and initiate (homologous/nonhomologous) recombination.

Answer 40

homologous

Question 41

Werner syndrome is autosomal recessive what type of manifest in the eye does it have?

Answer 41

cataracts

Question 42

``` Autosomal recessive: stunted growth sunlight sensitivity chromosome breakage immunologic deficiency infertility increased risk for neoplasia --describes (bloom syndrome/werner syndrome) ```

Answer 42

bloom syndrome

Question 43

Autosomal recessive cataracts changing of skin conditions atypical short stature premature graying or thinning of the hair. Patients also often develop hypogonadism, osteoporosis, diabetes mellitus, atherosclerosis and cancers (sarcomas) --describes (bloom syndrome/werner syndrome)

Answer 43

werner syndrome

Question 44

both werner syndrome and bloom syndrome mutations in the helicase of Rec Q family

Answer 44

T