Exam 2 review

Question 1

What trans-acting elements in a holoenzyme increases processivity during DNA replication?

Answer 1

clamp loader and clamp

Question 2

Base excision repair utilize which enzyme(s) to remove the damaged base?

Answer 2

glycosylase and lyase

Question 3

True or False: a kinetochore is a DNA cis element that recruits the centromere?

Answer 3

False

Question 4

What are the three general steps in bacterial DNA replication?

Answer 4

initiation, elongation, termination

Question 5

The term ____________ is in reference to a polymerase with the ability to scrutinize newly added bases as they are added and correct any errors.

Answer 5

proofreading

Question 6

The “hand” structure of a typical DNA polymerase has three primary domains. Which statement(s) that is(are) true about the hand

Answer 6

the “thumb” interacts with DNA exiting the polymerase, the “palm” represents the main catalytic domain of the polymerase, and DNA lies across the “palm”

Question 7

The puffs on a polytene chromosome represent areas of…

Answer 7

active gene expression.

Question 8

What trans-acting elements regulate or interact with a prokaryotic ori?

Answer 8

DnaA, DnaB, and DnaC

Question 9

Which of the following components represent parts of the replisome?

Answer 9

β-clamp, helicase, replication fork, and holoenzyme

Question 10

What cis-acting element is a target for Dam methylase?

Answer 10

GATC sequence motif

Question 11

True or False: DNA polymerase epsilon exhibits higher processivity than DNA polymerase delta.

Answer 11

True

Question 12

In yeast a(an) _______________ is functionally similar to a bacterial ori.

Answer 12

autonomous replicating sequence

Question 13

True or False: DNA repair mechanisms are roughly equivalent in terms of fidelity.

Answer 13

False

Question 14

DNA replication in prokaryotes and eukaryotes is…

Answer 14

bidirectional for both.

Question 15

Which is true regarding licensing factors in eukaryotic DNA replication?

Answer 15

the nuclear membrane to regulate interaction of licensing actors with DNA

Question 16

When duplex DNA is unwound at a replication bubble tension builds from overwinding of the helix. What enzyme(s) is(are) able to release the tension while maintaining control of the DNA strands?

Answer 16

Topoisomerase II, Topoisomerase I, and Topoisomerase II

Question 17

A core histone octamer is composed of…

Answer 17

two H2A-H2B heterodimers and a H32-H42 tetramer.

Question 18

Similar to prokaryotes the sequence of origin of replications show very little variability in a vertebrate genome.

Answer 18

False

Question 19

True or False: Recombination-repair always restores damaged DNA back to the original sequence.

Answer 19

False

Question 20

True or False: In general core histone acetylation is associated with transcriptionally active regions of DNA

Answer 20

True

Question 21

Euchromatin is …

Answer 21

transcriptionally active.

Question 22

In G-U mismatch repair the Uracil is preferentially replaced because…

Answer 22

uracil is not normally used n DNA

Question 23

True or False: Yeast generally have one origin of replication.

Answer 23

False

Question 24

Benzo(a)pyrene linkage to a guanine nucleotide is an example of…

Answer 24

an adduct and helix distorting damage

Question 25

What direction is a DNA template read during replication?

Answer 25

3' to 5'

Question 26

MTOC stands for ...

Answer 26

microtubule organizing center

Question 27

Which statement is true about accentric fragments?

Answer 27

an accentric fragment lacks a centromere and an accentric fragment can occur from double strand breaks in DNA

Question 28

True or False: In bacteria hemimethylated DNA is necessary for DNA replication.

Answer 28

False

Question 29

True or False: Tau is responsible for dimerization of E. coli's DNA polymerase III holoenzyme in the replisome.

Answer 29

True

Question 30

Which is a trans-acting licensing factor in bacterial replication?

Answer 30

Dam methylase

Question 31

Nucleoid associated proteins ...

Answer 31

facilitate packaging of the bacterial genome.

Question 32

What enzyme's activity can release the tension in an overwound circular DNA molecule?

Answer 32

Topoisomerase II, Topoisomerase I, Endonuclease, and Nickase

Question 33

Which core histones contribute to a core histone octamer? Select all that apply.

Answer 33

H3, H2B, H2A, andH4

Question 34

During replication, mismatch repair preferentially corrects the base in which DNA strand?

Answer 34

nascent strand

Question 35

True or False: During DNA synthesis a seed sequence is always derived from an RNA primase.

Answer 35

False

Question 36

Why is DNA damage repaired by non-homologous end joining (NHEJ) more likely to result in a deleterious mutation than most other repair systems?

Answer 36

NHEJ does not use any template sequence to direct repair

Question 37

True or False: Helicase can initiate the melting of duplex DNA

Answer 37

False

Question 38

True or False: Processivity generally improves a polymerases fidelity.

Answer 38

True

Question 39

True or False: A nick in DNA during DNA replication can result in an acentric fragment.

Answer 39

True

Question 40

True or False: kinetochores attach a centromere to microtubules?

Answer 40

True

Question 41

During bacterial replication what enzyme removes the RNA primer and replaces it with DNA?

Answer 41

DNA pol I