DNA REPLICATION

Question 1

DNA strands serve as

Answer 1

template for synthesis of one another

Question 2

two newly synthesized strands come together, original helix is preserved, this is what replication

Answer 2

Conservative

Question 3

parental strands are dispersed into two new double helices, this is which replication

Answer 3

dispersive replication

Question 4

in this replication, each replicated DNA molecule consists of one “old” and one new strand

Answer 4

Semiconservative

Question 5

DNA replication in E.COLI is

Answer 5

semiconservative

Question 6

what is the direction of DNA replication

Answer 6

bidirectional

Question 7

what is the origin of replication of eukaryotic chromosomes

Answer 7

multipple origin of replication

Question 8

bacterial chromosomes have how many origin of replication

Answer 8

single

Question 9

when new DNA is synthesized in both direction from the single origin, it creates what

Answer 9

an expanding replication bubble

Question 10

when is replication complete

Answer 10

when the replication fork meet

Question 11

when an helix unwounds, it creates a

Answer 11

replication fork

Question 12

length of DNA replicated is called

Answer 12

Replicon

Question 13

requirement for replication in linear eukaryote

Answer 13

1. template strand
2. raw material: nucleotides
3. enzymes and other protein

Question 14

DNA synthesis / replication run from

Answer 14

5’ to 3’

Question 15

DNA polymerase adds nucleotide to which end

Answer 15

3’ end of growing strand

Question 16

what has the most characterized ORI sequences

Answer 16

yeast (Saccharomyces cerevusiae)

Question 17

multiple origin of replication are called

Answer 17

Autonomously replicating sequences (ARS)

Question 18

Initiation of replication process

Answer 18

1. Dna A binds to the 9-mer repeats, bends DNA and breaks hydrogen bonds in the 13-mer regions
2. DnaB is a helicase that uses ATP energy to break hydrogen bonds to separate the strand and unwind helix
3. Dna B is carried to DNA helix by Dna C
4. Unwound DNA are kept from reannealing by SSB
5. unwinding of chromosomes leads to supercoiled DNA
6. topoisomerases catalyze controlled cleavage and rejoins DNA to prevent overwinding

Question 19

Can DNA polymerase initiate DNA strand synthesis on their own

Answer 19

no, they need RNA primers

Question 20

what is teh name of the specialized RNA polymerase

Answer 20

primase

Question 21

which DNA polymerase is abundant but not ideal for replication, its main job is clean-up

Answer 21

DNA polymerase I

Question 22

which DNA polymerase is the principal replication polymerase

Answer 22

DNA polymerase III

Question 23

WHICH DNA polymerase are involved in DNA repair

Answer 23

DNA polymerase II,IV & V

Question 24

WHICH of these two strands does DNA polymerase synthesise 5’ to 3’ to 3’ to 5’

Answer 24

5’ to 3’

Question 25

which is the continous DNA synthesis

Answer 25

leading strand

Question 26

which is the discontinuous DNA synthesis

Answer 26

lagging strand

Question 27

which polymerase is involved in removing an RNA primer nucleotide and adding a DNA nucleotide

Answer 27

DNA polymerase I

Question 28

what happens when the primer removal is finished in the strand

Answer 28

dna ligase replaces pol I at DNA-DNA single strand gaps catalyzing formation of a phosphodiester bond

Question 29

single steranded binding (SSB) protein coats single-stranded DNA to prevent

Answer 29

reannealing

Question 30

why must DNA form a loop

Answer 30

so that both strands can replicate simultaneously

Question 31

Characteristics of DNA replication

Answer 31

1. Semiconservative 2. bidirectional 3. Semidiscontinous

Question 32

when the leading strand copies continuously an dteh lagging strand copies in segments. This is called

Answer 32

semidiscontinuous

Question 33

how is eukaryotic DNA replication differ from Bacterial Replication

Answer 33

multiple origin Telomeres and telomerase

Question 34

Ends of DNA contain a tandem repetitive sequence called

Answer 34

Telomeres

Question 35

the answer to Teloneres is

Answer 35

telomerase

Question 36

HOw do telomerase function

Answer 36

template RNA of telomerase allows new DNA replication to lengthen the telomere sequence Once telomeres are elongated, polymerase synthesised additional RNA primers New DNA replication then fills out chromosomes ends

Question 37

telomerase is active in

Answer 37

germ-line cells and some stem sells in eukaryote