Ch. 11 Concept Check & Comprehension Questions Flashcards Preview

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Flashcards in Ch. 11 Concept Check & Comprehension Questions Deck (24):
1

The complementarity of DNA strands is based on..

The AT/GC rule

2

To make a new DNA strand, what is necessary?

A template strand and nucleotides

3

The model that correctly describes the process of DNA replication is..

The semiconservative model

4

A site in a chromosome where DNA replication begins is..

An origin of replication

5

The origin of replication of E. coli contains..

- an AT-rich region
- DnaA box sequences
- GATC methylation sites

6

The enzyme known as ___ uses ___ and separates the DNA strands at the replication fork.

Helicase, ATP

7

In the lagging strand, DNA is made in the direction ___ the replication fork is made as ___.

Away from, Okazaki fragments

8

DNA polymerase III is a processive enzyme, which means that..

It does not dissociate from the growing strand after it has attached a nucleotide to the 3' end.

9

The proofreading function of DNA polymerase involves the recognition of a ___ and the removal of a short segment of DNA in the ___ direction.

Base mismatch, 3' to 5'

10

In eukaryotes, DNA replication is initiated at an origin of replication by..

The origin recognition complex

11

Which of the following statements regarding DNA polymerase in eukaryotes is NOT correct?

All are correct.

DNA polymerase alpha synthesizes a short RNA-DNA primer

DNA polymerases E and 8 synthesize most of the leading and lagging, respectively

Lesion-replicating DNA polymerases can replicate over damaged DNA

12

In eukaryotes, RNA primers are primarily removed by..

Flap endonuclease

13

To synthesize DNA, what does telomerase use as a template?

It uses RNA that is a component of telomerase

14

The structural basis for DNA replication.

What features of DNA structure enable it to be replicated?

The two features that allow DNA to be replicated are its double-stranded structure and the base pairing between A and T and between G and C.

15

The sequence of oriC in E. coli

What are the functions of the AT-rich region and DnaA boxes?

The DnaA boxes are recognized by DnaA protein, which binds to them and causes the DNA to unwind at the AT-rich region.

16

The events that occur at oriC to initiate the DNA replication process.

How many replication forks are formed at the origin?

Two replication forks are formed at the origin.

17

The proteins involved with bacterial DNA replication.

Why is primase needed for DNA replication?

Primase is needed for DNA replication because DNA polymerase cannot initiate DNA replication on a bare template strand.

18

The action of DNA polymerase.

Is the template strand read in the 5' to 3' or the 3' to 5' direction?

The template strand is read in the 3' to 5' direction.

19

The synthesis of DNA at the replication fork.

Describe the differences between the synthesis of the leading and lagging strands.

The leading strand is made as one, long continuous strand in the same direction that the replication fork is moving.

The lagging strand is made as Okazaki fragments in the direction away from the replication fork.

20

A three-dimensional view of DNA replication.

What is the advantage of having the replication machinery in a complex?

Having the replication machinery in a complex allows the coordination of different enzymes. For example, helicase and primase can work together to make multiple primers for the lagging strand.

21

Separation of catenanes.

Is DNA strand breakage needed for catenane separation?

Yes, so the strands can move relative to each and untangle the catenane.

22

The enzymatic action of DNA polymerase.

Does the oxygen in the newly made ester bond come from the phosphate or from the sugar?

The oxygen in the newly made ester bond comes from the sugar.

23

The replication of eukaryotic chromosomes.

Why do eukaryotes need multiple origins of replication?

Because eukaryotic chromosomes are so large, they need multiple origins so the DNA can be replicated in a reasonable length of time.

24

The enzymatic action of telomerase.

How many times would telomerase have to bind to a different site in the telomere to make a segment of DNA that is 36 nucleotides in length?

36/6 = 6 times