DNA repair

Question 1

In E coli DNA repair is done by which proteins

Answer 1

Mut proteins

mismatch repair

Question 2

Newly Synthesized DNA is ____ {methylated/hemimethylated}

Answer 2

Hemimethylated

parental strand is methylated and daughter strand is not

Question 3

In which disease is there mutated mismatched repair proteins

Answer 3

Hereditary nonpolyposis colorectal cancer {HNPCC}

aka Lynch syndrome

Question 4

Which proteins excise Thymine dimers in E coli

by nucleotide excision repair

Answer 4

UvrABC excinuclease

it is a UV specific endonuclease

Question 5

Which proteins excise Thymine dimers in humans

Answer 5

XP proteins

Question 6

In which disease are there early skin cancer due to damage DNA repair {nucleotide excision repair}

Answer 6

Xeroderma Pigmentosum

Question 7

Which DNA repair mechanism will be present in case of Nitrous acid intoxication

convert cytosine to uracil adenine to hypoxanthine guanine to xanthine

Answer 7

Base Excision Repair

Question 8

Which kind of double stranded repair is less prone to cancer

Answer 8

Homologous

non homologous may lead to loss of dna as both strand are joined aise hi

Question 9

Name a disease due to non homologous joining repair

Answer 9

Ataxia telangiectasia

Question 10

Name diseases with defect in homologous joining repair

Answer 10

Defect in breast/ovarian cancer
Fanconi anemia

breast cancer due to defect in BRCA1 and BRCA2

Question 11

In which phase of cell cycle does nucleotide excision repair takes place

Answer 11

G1 phase

Question 12

In which phase of cell cycle does base excision repair takes place

Answer 12

all throughout cell cycle

Question 13

Which repair help in fixing spontaneous toxic deamination

Answer 13

Base excision repair

Question 14

In which phase does mismatch repair take place

Answer 14

S Phase

Question 15

Which mutation is involves in wobble hypothesis

Answer 15

Silent mutation

Question 16

Which mutation is involved in sickle sense anemia

Answer 16

missense mutation

Question 17

Which mutation is involved in Duchenne muscular dystrophy

Answer 17

Frameshift mutation

Question 18

What all disease are involves in frameshift mutation

addition or deletion of any no of nucleotide not divisible by 3

Answer 18

Duchenne muscular dystrophy
Cystic fibrosis
Tay sachs disease

Question 19

what all disease are involved in splice site mutation

intron not cleaved

Answer 19

Gaucher
Marfan
b thalassemia
Tay Sachs
Cancer
Epilepsy

Question 20

Lac genes are strongly expressed in which state of lac operon

Answer 20

When glucose is low and lactose is present

Question 21

Enzymes involved in base excision repair

Answer 21

Glycosylase
AP endonuclease
deoxyribose phosphate lyase
DNA polymerase
DNA ligase

in that order

Question 22

Mutation in gamete dna is called

Answer 22

Germline mutation

Question 23

A ______mutation is a change in one nucleotide in a gene sequence.

Answer 23

point