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Question 1

Where does the replication starts

Answer 1

At a specific sequence of DNA called the origin of replication

Question 2

Origin of replication in prokaryotic cells

Answer 2

Single&raquo_space;oriC

Question 3

Origin of replication in eukaryotic cells

Answer 3

Multiple&raquo_space;autonomous replication sequences (ARS)

Question 4

What enzyme initiate the DNA separation

Answer 4

DNAa (it recognize the bases sequence at the origin of replication and separate a small region in the origin by atp hydrolysis)

Question 5

DNA helicase enzyme function

Answer 5

Breaking the hydrogen bonds between the DNA strands using ATP

Question 6

Single strand DNA binding proteins (SSB) function

Answer 6

Prevent the separated strands from rejoining & protect the single strand of DNA from nucleases

Question 7

Pre priming complex is composed of what

Answer 7

DNAa protien+DNAc helicase loader+ssb protien +DNA helicase DNAb protien

Question 8

Function of the pre priming complex

Answer 8

1. Replication initiation
2. Maintaining the DNA strands separation

Question 9

The 2 strands separation create what

Answer 9

Supercoils(prevent further separation)

Question 10

Function of DNA topoisomerase

Answer 10

Removes the supercoils

Question 11

Topoisomerase consists of what

Answer 11

1. Nuclease (strand cutting)
2. Ligase( strand releasing)

Question 12

DNA gyrase function

Answer 12

Subclass of type 2 topoisomerase&raquo_space;deal with negative supercoils

Question 13

E.g on quinolones antimicrobial drugs

Answer 13

Ciprofloxacin,,levofloxacin( inhibit bacterial gyrase )

Question 14

E.g on anticancer drugs

Answer 14

Topotecan(target topoisomerase 1)
Etoposide(target topoisomerase 2)

Question 15

Bloom syndrome cause

Answer 15

Defect in DNA helicase

Question 16

DNA polymerases function

Answer 16

They add complementary nucleic Acid chain by forming phosphodiester bonds