Replicating genetic material and DNA repair

Question 1

Defines the nucleus

Answer 1

Nuclear envelope

Question 2

Network of intermediate filaments which form a thin mesh just beneath
the inner nuclear membrane for DNA replication

Answer 2

Nuclear lamina

Question 3

DNA =

Answer 3

deoxyribonucleic acid

Question 4

How are the strands of DNA held together

Answer 4

Hydrogen bonds

Question 5

Strands of DNA are ________ and act as a template

Answer 5

complementary

Question 6

What does it mean to be ‘semi-conservative’

Answer 6

Each of the two daughters of a dividing cell inherits a new DNA double helix containing one original
and one new strand

Question 7

DNA synthesis begins at

Answer 7

Replication origins

Question 8

Localised region of replication that moves progressively along the parental DNA double helix

Answer 8

Replication fork

Question 9

What pulls the strands of DNA apart and produces the replication bubble

Answer 9

DNA helicase

Question 10

True or false: G-C pairs are easier to pull apart because they are connected by less hydrogen bonds

Answer 10

False

Question 11

What do single stranded DNA binding proteins do?

Answer 11

Stabilise the DNA into a linear structure and avoid the formation of hairpins

Question 12

What enzyme copies the DNA

Answer 12

DNA polymerase

Question 13

What direction does DNA synthesis occur in

Answer 13

5’ to 3’

Question 14

Most DNA polymerases contain
a proof-reading _______________
activity

Answer 14

3’-5’ exonuclease

Question 15

What strand is synthesised continuously from 5’ to 3’

Answer 15

Leading strand

Question 16

True or false: formation of the lagging strand is discontinuous

Answer 16

True

Question 17

What are the fragments added to the lagging strand called

Answer 17

Okazaki fragments

Question 18

What enzyme joins fragments together by forming covalent bonds

Answer 18

DNA ligase

Question 19

Supercoiling of DNA produces

Answer 19

Torsional stress

Question 20

What enzyme induces a swivel point to reduce torsional stress

Answer 20

DNA topoisomerase

Question 21

__________ are packaged into specialized structures that protect
the ends of chromosomes

Answer 21

Telomeres

Question 22

True or false: telomeres lengthen with each cell division

Answer 22

False

Question 23

DNA primase adds

Answer 23

RNA primers

Question 24

Removes a specific type of altered/damaged base

Answer 24

Base excision repair (BER)

Question 25

___________ travels along DNA using base-flipping to check status of each base

Answer 25

DNA glycosylase

Question 26

Repairs large bulk helix distorting lesions

Answer 26

Nucleotide excision repair

Question 27

Repair double stranded breaks in any phase of the cell cycle using Ku heterodimers

Answer 27

Nonhomologous End Joining (NHEJ)

Question 28

Repair double stranded breaks in G2 via strand exchange between homologous DNA sequences

Answer 28

Homologous recombination

Question 29

Strand directed mismatch repair system removes replication errors that escape from the replication machinery

Answer 29

Mismatch repair (MMR)

Question 30

What are the main molecules involved in mismatch repair

Answer 30

MutS and MutL