The two strands of DNA in a double helix associate with one another due to ____ bonding between opposite bases in the helix and due to the nucleotides stacking on top of one another to form a ladder-like structure.

hydrogen

Parental DNA strands are used as templates to produce daughter DNA strands during the process called ____ ____.

DNA replication

When two strands of DNA associate to form a double helix, the bases on opposite strands of DNA interact via hydrogen bonds. Different numbers of hydrogen bonds form between the different base-pairs: there are ____ hydrogen bonds between adenine and ____, and between cytosine and ____ there are ____ hydrogen bonds.

2; thymine; guanine; 3

In the DNA double helix, there are ____ strands of DNA.

2 or double

Select all that apply

Which of the following are analogous to the antiparallel arrangement of strands of DNA in a double helix?

Multiple select question.

Two pencils laid next to one another pointing in opposite directions

A single set of train tracks

Two pencils laid end to end (eraser to tip, eraser to tip)

A two lane, two way highway with a divider/median

Two pencils laid next to one another pointing in opposite directions

A two lane, two way highway with a divider/median

Individual strands of DNA are composed of building blocks called

nucleotides

In a DNA double helix, one strand of DNA runs 5' to 3' and the other strand runs 3' to 5'. Because the two strands are arranged like this and never cross one another, the two strands are said to be

antiparallel

Select all that apply

What are the types of bases found in DNA?

Multiple select question.

Thymine

Cytosine

Guanine

Adenine

Ribose

Uracil

Deoxyribose

Thymine

Cytosine

Guanine

Adenine

Select all that apply

How are the two strands of DNA held together in a double helix?

Multiple select question.

Ionic bonds between opposite bases

Stacking of the bases on top of one another

Phosphodiester bonds between opposite bases

Hydrogen bonds between opposite bases

Stacking of the bases on top of one another

Hydrogen bonds between opposite bases

What is the name given to the strand of DNA that contains the information to make the new strand of DNA during DNA replication?

Multiple choice question.

The conserved strand

The template strand

The complementary strand

The daughter strand

The template strand

Select all that apply

Which of the following demonstrate correct base pairing?

Multiple select question.

C - G with 2 hydrogen bonds

A - T with 2 hydrogen bonds

C - G with 3 hydrogen bonds

A - T with 3 hydrogen bonds

A - T with 2 hydrogen bonds

C - G with 3 hydrogen bonds

What is the name of the new strand of DNA that is produced during DNA replication?

Multiple choice question.

The coding strand

The daughter strand

The template strand

The parental strand

The daughter strand

Escalators usually come in pairs; one moves people upwards between floors and one moves people downward between floors. Given that one goes in one direction and the other goes in the other direction, and they don't cross over one another, this is an example of something that is ______.

Multiple choice question.

antiparallel

confluent

redundant

parallel

complimentary

antiparallel

Match the three proposed models of DNA replication with the correct description.

Dispersive

Conservative

Semiconservative

The daughter molecules of DNA consist of one strand of parental DNA and one complementary strand of newly formed DNA.

Both strands of parental DNA remain together following replication and the daughter molecule consists of only newly synthesized DNA strands.

Pieces of parental DNA and newly synthesized DNA are interspersed throughout both daughter strands in the newly formed molecule.

• Dispersive Pieces of parental DNA and newly synthesized DNA are interspersed throughout both daughter strands in the newly formed molecule.

• Conservative Both strands of parental DNA remain together following replication and the daughter molecule consists of only newly synthesized DNA strands.
• Semiconservative
  The daughter molecules of DNA consist of one strand of parental DNA and one complementary strand of newly formed DNA.

As shown in the figure, the two strands of the DNA double helix run in opposite directions: one runs 5' to 3' and the other runs 3' to 5'. Also, the two strands never cross one another. This arrangement of the two strands of DNA in a double helix as described as

antiparallel

In the Meselson and Stahl experiment, E.coli was first grown in medium containing ¹⁵N compounds such that all N in the DNA contained ¹⁵N. The cells were then grown in medium containing ¹⁴N for various periods of time. The bacterial lysate was then separated by CsCl centrifugation. The experiment yielded the data in the image shown. This experiment suggested that DNA replication is

semiconservative

The figure shows data from Meselson and Stahl's experiment to determine the mechanism of DNA replication. After one generation, which model(s) for DNA replication does the data support?

Multiple choice question.

Only the dispersive model

Both semiconservative and dispersive models

Only the conservative model

Only the semiconservative model

Both semiconservative and conservative models

Both conservative and dispersive models

Both semiconservative and dispersive models

The strand of DNA that contains the information used to make a new strand of DNA during DNA replication is called the ____ strand.

template

The area highlighted in yellow, where DNA replication begins, is called the ____ ____ ____.

origin of replication

The strand of DNA that is produced during DNA replication is generally called the ____ strand.

daughter

Because DNA replication proceeds in both directions from a single origin of replication, it is said to be ____ replication.

bidirectional

Match the three proposed types of replication with the correct figure.

Instructions

A

B

C

Semiconservative model

Dispersive model

Conservative model

• A Conservative model
• B Semiconservative model
• C Dispersive model

The sites where the parental template strands of DNA separate during replication are called the ____ ____.

replication fork

List the steps of Meselson and Stahl's experiment, which provided evidence of semiconservative DNA replication, in the correct sequence.

Lyse the cells and separate the lysate in a CsCl gradient.

Add ¹⁴N to the growth medium and incubate for various lengths of time such that all newly formed DNA will contain ¹⁴N.

Grow E. coli in the presence of ¹⁵N for many generations such that all of the N in the DNA is labeled with ¹⁵N.

Centrifuge the gradients such that all DNA molecules reach their equilibrium densities.

Observe the DNA under UV light.

1) Grow E.coli in the presence of 15N for many generations such that all of the N in the DNA is labeled with 15N.
2) Add 14N to the growth medium and incubate for various lengths of time such that all newly formed DNA will contain 14N.
3) Lyse the cells and separate the lysate in a CsCl gradient.
4) Centrifuge the gradients such that all DNA molecules reach their equilibrium densities.
5) Observe the DNA under UV light.

The figure shows data from Meselson and Stahl's experiment to determine the mechanism of DNA replication. After 1.9 generations, which model(s) for DNA replication does the data support?

Multiple choice question.

Both the conservative and dispersive models

Only the conservative model

Only the dispersive model

Only the semiconservative model

Both the semiconservative and dispersive models

Only the semiconservative model

DNA replication begins at a site called the ____ of ____.

origin of replication

The three types of DNA sequences located within the oriC complex are the ____ rich region, ____ box sequence and the ____ methylation site.

AT

DNAa

GATC

As shown in the image, bacterial DNA replication occurs ____ from a single origin of replication.

bidirectionally

For E. coli, what occurs prior to helicase binding and creating two replication forks?

Multiple choice question.

DnaA proteins bind to sequences in the five DnaA boxes

Initiation factors bind to the promoter

mRNA binds to the ribosome

DNA polymerase binds to the template strand

DnaA proteins bind to sequences in the five DnaA boxes

The areas at the tips of the arrows in this replicating molecule of DNA are called the ____ ____.

replication forks

DNA helicase ______.

Multiple choice question.

joins two Okasaki fragments together

separates double-stranded DNA into two single strands

removes positive supercoils that accumulate ahead of the replication fork

creates negative supercoils in DNA molecules

separates double-stranded DNA into two single strands

The name of the enzyme that methylates the GATC methylation site within the oriC is

DAM

Identify the proteins shown in the image that are involved in E. coli DNA replication.

A

B

C

D

E

F

DNA ligase

DNA polymerase III

Topoisomerase II

Single stranded binding protein

Primase

DNA helicase

• A DNA polymerase III
• B Single stranded binding protein
• C DNA helicase
• D Topoisomerase II
• E Primase
• F DNA ligase

Select all that apply

Select the three types of DNA sequences located within the oriC complex.

Multiple select question.

Promoter

DnaA box sequence

AT-rich region

Replication fork

GATC methylation site

DnaA box sequence

AT-rich region

GATC methylation site

List the events that occur at oriC to initiate DNA replication, putting the first step at the top.

DNA helicase proteins bind to the origin

HU, IHF and other DNA binding proteins cause the DNA to wrap around the DnaA complex

DNA helicase separates the DNA in both directions creating two replication forks

DnaA protein binds to the DnaA box sequence

The double-stranded DNA molecule separates at the AT-rich region

Answer in the picture.

The role of topoisomerase II (DNA gyrase) in replication is to ______.

Multiple choice question.

synthesize the RNA primer

synthesize new DNA

stabilize the replication fork

break hydrogen bonds between complementary bases

remove positive supercoiling in the DNA

remove positive supercoiling in the DNA

The enzyme that converts a double-stranded DNA region into two single strands by breaking the hydrogen bonds between the strands is called DNA ____.

helicase

Proteins that function to stabilize the replication fork by preventing the reformation of the double strand are called ______.

Multiple choice question.

helicases

GATC methylation sites

single strand binding proteins

DNA polymerases

topoisomerases

single strand binding proteins

During DNA replication, what is the role of the GATC methylation site within the oriC?

Multiple choice question.

Promote termination of replication

Recruit DNA helicase to bind

Regulate DNA replication initiation

Alleviate positive supercoiling

Regulate DNA replication initiation

The enzyme that synthesizes the short molecules of RNA, called RNA primers, is called ____.

primase

Match the following proteins with the function they serve in E. coli DNA replication.

Primase

DNA polymerase III

DNA polymerase I

DNA ligase

Tus

Synthesizes RNA primers

Covalently attaches adjacent Okazaki fragments

Removes RNA primers and fills the gaps with DNA

Binds to ter sequences, preventing the advancement of the replication fork

Synthesizes DNA of both leading and lagging strand

• Primase Synthesizes RNA primers
• DNA polymerase III Synthesizes DNA of both leading and lagging strand
• DNA polymerase I Removes RNA primers and fills the gaps with DNA
• DNA ligase Covalently attaches adjacent Okazaki fragments
• Tus Binds to ter sequences, preventing the advancement of the replication fork

Which newly synthesized DNA molecule has multiple primers?

Multiple choice question.

Lagging strand

Leading strand

Lagging strand

The name of the enzyme that travels in front of helicase to remove positive supercoiling in the DNA is called ____ ____.

DNA gyrase or topoisomerase II

What is the function of DNA polymerase?

Multiple choice question.

Synthesis of RNA primers

Stabilization of the replication fork

Synthesis of DNA on both the leading and lagging strands

Reduction of positive supercoiling in the DNA

Synthesis of DNA on both the leading and lagging strands

Identify the role of single-strand binding proteins.

Multiple choice question.

Stabilize the replication fork by preventing the reformation of the double strand

Break hydrogen bonds between complementary bases

Synthesize the RNA primer

Remove positive supercoiling in the DNA

Synthesize the new DNA molecule

Stabilize the replication fork by preventing the reformation of the double strand

The short molecules of RNA that start the DNA replication process are called ____ ____.

RNA primers

Select all that apply

Identify the three DNA polymerases found in E. coli that play a role in the replication of damaged DNA and DNA repair.

Multiple select question.

DNA polymerase II

DNA polymerase III

DNA polymerase V

DNA polymerase I

DNA polymerase IV

DNA polymerase II

DNA polymerase V

DNA polymerase IV

Which newly synthesized DNA molecule has a single primer?

Multiple choice question.

Lagging strand

Leading strand

Leading strand

Which DNA polymerase involved in E. coli DNA replication consists of 10 subunits?

Multiple choice question.

DNA polymerase IV

DNA polymerase III

DNA polymerase I

DNA polymerase II

DNA polymerase III

List the functions of key proteins involved with bacterial DNA replication

Answer in the picture.

Which enzyme synthesizes the DNA of both the leading and lagging strand?

Multiple choice question.

DNA polymerase

RNA primase

Helicase

DNA gyrase

DNA polymerase

DNA polymerase can only add nucleotides in the ____ to ____ direction.

5' to 3'

Proteins that function to stabilize the replication fork by preventing the reformation of the double strand are called ______.

Multiple choice question.

GATC methylation sites

topoisomerases

DNA polymerases

single strand binding proteins

helicases

single strand binding proteins

During DNA replication, synthesis of the ____ strand is continuous while synthesis of the ____ strand is discontinuous.

leading; lagging

Select all that apply

Identify the two DNA polymerases found in E. coli that play a role in normal DNA replication.

Multiple select question.

DNA polymerase IV

DNA polymerase II

DNA polymerase III

DNA polymerase V

DNA polymerase I

DNA polymerase III

DNA polymerase I

Match the following proteins involved in E. coli DNA replication with the correct function.

DnaA proteins

DnaC proteins

DnaB (helicase)

Topoisomerase II (DNA gyrase)

Single stranded binding proteins

Removes positive supercoiling ahead of the replication forks

Bind to DnaA box proteins within the oriC to initiate DNA replication

Separates double-stranded DNA

Aid DnaA in the recruitment of helicase to the origin

Bind to single-stranded DNA and prevent it from re-forming a double-stranded structure

• DnaA proteins Bind to DnaA box proteins within the oriC to initiate DNA replication
• DnaC proteins Aid DnaA in the recruitment of helicase to the origin
• DnaB (helicase) Separates double-stranded DNA
• Topoisomerase II (DNA gyrase) Removes positive supercoiling ahead of the replication forks
• Single stranded binding proteins Bind to single-stranded DNA and prevent it from re-forming a double-stranded structure

Small segments of DNA synthesized on the lagging strand of DNA are called ___ ___.

Okazaki fragments

DNA polymerase III is a complex of ______ subunit(s) while DNA polymerase I is composed of ______ subunit(s).

Multiple choice question.

5 ; 3

3 ; 1

1 ; 5

10 ; 1

10 ; 3

10 ; 1

DNA polymerase attaches nucleotides to the newly synthesized strand in the ______.

Multiple choice question.

5'-to-3' direction or the 3'-to-5' direction

3'-to-5' direction only

5'-to-3' direction only

5'-to-3' direction only

The enzyme that catalyzes the formation of a covalent phosphodiester bond between adjacent Okazaki fragments is called DNA

ligase

List the events of DNA synthesis at the replication fork in the correct sequence.

DNA strands separate at the origin, creating two replication forks.

DNA polymerase I removes the primers and adds DNA.

DNA ligase catalyzes the phosphodiester bond between adjacent Okazaki fragments.

RNA primers are added to both the leading and lagging strand.

DNA polymerase III adds nucleotides to the 3' end continuously on the leading strand, and discontinuously on the lagging strand.

Answer in the picture.

Select all that apply

Which components are needed to make up the complex called a primosome?

Multiple select question.

DNA polymerase III

primase

topoisomerase II

DNA polymerase I

DNA ligase

DNA helicase

primase

DNA helicase

Small segments of DNA, called Okazaki fragments, are synthesized on the ____ ____.

Lagging strand

What is a replisome?

Multiple choice question.

A primosome physically associated with two DNA polymerase holoenzymes

A complex of two DNA polymerase molecules

A primase complexed with DNA helicase

DNA ligase associated with an Okazaki fragment

A primosome physically associated with two DNA polymerase holoenzymes

Which DNA polymerase involved in E. coli DNA replication consists of 10 subunits?

Multiple choice question.

DNA polymerase III

DNA polymerase IV

DNA polymerase II

DNA polymerase I

DNA polymerase III

In dimeric DNA polymerase, two molecules of DNA polymerase _____ act together to replicate the leading and lagging strands of DNA.

Multiple choice question.

IV

III

I

II

V

III

Which enzyme catalyzes the formation of a covalent bond between adjacent Okazaki fragments?

Multiple choice question.

DNA gyrase

DNA polymerase I

RNA primase

DNA ligase

Helicase

DNA ligase

Identify the protein that binds to the ter sequence to terminate DNA replication.

Multiple choice question.

oriC

DnaA

Tus

DnaB

Tus

A complex consisting of DNA helicase and primase is called a ____.

primosome

Two transiently intertwined molecules of DNA are called a ____.

catenanes

A primosome physically associated with two DNA polymerase holoenzymes is called a ____.

replisome

A temperature-sensitive mutant is an example of a ____ mutant.

conditional

A complex of two DNA polymerase holoenzymes that move as a unit during DNA replication is described as ______ DNA polymerase.

Multiple choice question.

conjoined

duplex

dimeric

paired

dimeric

The energy used to fuel the endergonic reaction of DNA replication is supplied from the exergonic cleavage of ______.

Multiple choice question.

the primosome

adenosine triphosphate (ATP)

DNA polymerase

the replisome

a deoxyribnucleoside triphosphate (dNTP)

a deoxyribnucleoside triphosphate (dNTP)

The area of DNA where Tus binds to stop the movement of the replication fork is called a ____ ____.termin

termination sequence

DNA polymerase III does not dissociate from the DNA template strand after it has catalyzed the joining of two adjacent nucleotides so it is described as a ____ enzyme.

processive

What are catenanes?

Multiple choice question.

Promoter sequences where initiation factors bind

Transiently intertwined DNA molecules formed during DNA replication

Termination sequences that prevent the movement of the replisome

Transiently intertwined DNA molecules formed during DNA replication

Which molecule, when bound to DNA polymerase III forming a holoenzyme, dramatically increases the processivity of the enzyme?

Multiple choice question.

dNTP

DnaB

DnaA

β subunit

β subunit

A mutation that only blocks DNA replication when specific environmental conditions are present is called a ____ mutant.

conditional or ts

For E. coli, the protein that promotes dimerization of two DNA polymerase III proteins at the replication fork is encoded by which gene?

Multiple choice question.

dnaX

dnaG

dnaB

dnaC

dnaE

dnaX

True or false: The formation of covalent bonds between adjacent nucleotides during DNA replication requires energy input.

True false question.TrueFalse

True

DNA polymerase III is described as a(n) ____ enzyme since, as shown in the diagram, it remains clamped to the DNA template and slides along the template as it catalyzes the synthesis of the daughter strand.

processive

The speed of DNA replication depends on the ability of DNA polymerase III to remain attached to the template strand after catalyzing covalent bonds between adjacent nucleotides. For this reason, it is called a(n) ______ enzyme.

Multiple choice question.

progressive

processive

adhering

binding

catalyzing

processive

Select all that apply

Identify the three mechanisms that ensure the fidelity of DNA replication.

Multiple select question.

DNA polymerase active site structure

DNA proofreading

The ter sequence

Stability of base pairing

Processivity induced by binding of the β clamp

DNA polymerase active site structure

DNA proofreading

Stability of base pairing

In E. coli, the DNA polymerase III holoenzyme, which includes the β subunit, can add nucleotides at a rate of ______ nucleotides per second.

Multiple choice question.

about 750

only 20

about 2,000

more than 10,000

about 750

Select all that apply

Select all of these that are similar in both prokaryotes and eukaryotes.

Multiple select question.

Linear chromosomes

Chromatin compacted within nucleosomes

DNA ligases

DNA helicases

Primases

DNA ligases

DNA helicases

Primases

For E. coli, the protein that recruits DNA helicase to the origin of replication is encoded by which gene?

Multiple choice question.

dnaX

dnaC

dnaB

dnaG

dnaE

dnaC

In the diagram, DNA polymerase III surrounds the DNA molecule like a curled hand. This structural arrangement allows DNA synthesis to proceed rapidly due to the ______ of the enzyme.

Multiple choice question.

accuracy

processivity

precision

reactivity

processivity

Which type of cell has chromosomes with multiple origins of replication?

Multiple choice question.

Eukaryote

Prokaryote

Eukaryote

The three mechanisms that ensure the fidelity of DNA replication are the stability of ____ ____, the active site structure of DNA ____ and the process of DNA ____.

Stability of base pairing
DNA polymerase active site structure
DNA proofreading

In eukaryotes, DNA replication occurs ______ from multiple origins of replication.

Multiple choice question.

unidirectionally

bidirectionally

bidirectionally

Which molecule, when bound to DNA polymerase III forming a holoenzyme, dramatically increases the processivity of the enzyme?

Multiple choice question.

dNTP

β subunit

DnaA

DnaB

β subunit

Autonomously replicating sequences (ARS) are required to initiate DNA replication in ______.

Multiple choice question.

prokaryotes

eukaryotes

eukaryotes

Replication of the chromosome in the diagram is representative of that in a(n) ______.

Multiple choice question.

eukaryote.

prokaryote.

eukaryote

In eukaryotes, DNA replication begins with the ______.

Multiple choice question.

binding of MCM gyrase

assembly of a preRC

binding of MCM helicase

binding of DnaA

assembly of a preRC

True or false: Both prokaryotes and eukaryotes have multiple origins of replication.

True false question.TrueFalse

False
Reason:
Prokaryotes have a single origin of replication, while eukaryotes have multiple origins of replication.

DNA replication licensing allows DNA synthesis to begin after which protein binds to the origin of replication?

Multiple choice question.

primase

DNA polymerase α

DNA gyrase

MCM helicase

origin recognition complex (ORC)

MCM helicase

True or false: DNA replication in eukaryotes occurs unidirectionally from multiple origins of replication.

True false question.TrueFalse

False

In eukaryotes DNA polymerase ε synthesizes DNA on the ____ strand and DNA polymerase δ synthesizes DNA on the ____ strand.

leading; lagging

What consensus sequence is found in ARS elements?

Multiple choice question.

ATTATTATTATTATTATT

GCGCGCGCGCGCGC

ATTTAT (A or G) TTTA

AGCAGCAG (C or A) AA

ATTTAT (A or G) TTTA

A polymerase switch occurs when the complex of primase with DNA polymerase _____ is exchanged for DNA polymerase ______ on the leading strand and DNA polymerase ______ on the lagging strand.

Multiple choice question.

α; ε; δ

ε; α; δ

ε; δ; α

α; δ; ε

δ; ε; α

α; ε; δ

List the steps of eukaryotic DNA replication initiation in the correct sequence.

MCM helicases bind to the origin of replication

ORC binds to the origin of replication

DNA synthesis begins

1. ORC binds to the origin of replication.
2. MCM helicases bind to the origin of replication.
3. DNA synthesis begins.

What is the function of the complex of primase and DNA polymerase α?

Multiple choice question.

Unwind the DNA at the replication fork

Synthesize a short RNA-DNA primer

Synthesize DNA using the lagging strand as a template

Relax supercoils that form ahead of the replication fork

Synthesize DNA using the leading strand as a template

Synthesize a short RNA-DNA primer

A type of DNA polymerase that is attracted to damaged DNA and can synthsize a complementary strand over the abnormal region is called a - polymerase.

translesion replicating

In a process known as DNA replication ____, the binding of MCM helicase allows DNA replication to begin at an origin of replication in eukaryotic cells.

licensing

True or false: In both eukaryotes and prokaryotes RNA primers are removed by DNA polymerase I.

False

In eukaryotes, RNA primers are removed by flap endonuclease.

Match each eukaryotic DNA polymerase with the correct function.

α

ε

δ

γ

Replication of the leading strand

Initiate DNA replication

Replication of mitochondrial DNA

Replication of the lagging strand

• α Initiate DNA replication
• ε Replication of the leading strand
• δ Replication of the lagging strand
• γ Replication of mitochondrial DNA

The tandemly repeated DNA sequences located at the both ends of eukaryotic chromosomes, as shown in the image, comprise the ______.

Multiple choice question.

nucleosome

kinetochore

centromere

telomere

telomere

A ____ ____ is the exchange that occurs when a DNA polymerase α/primase complex dissociates from the replication fork and is replaced by DNA polymerase ε or δ.

polymerase switch

DNA polymerase cannot replicate the 3' end of a DNA strand because a ____ cannot be made upstream from this point.

primer

Select all that apply

A complex that synthesizes a short RNA-DNA complex used as a primer in eukaryotic DNA replication is made from which components?

Multiple select question.

DNA polymerase α

DNA polymerase ε

DNA polymerase δ

helicase

primase

DNA gyrase

DNA polymerase α

primase

The enzyme that synthesizes the short repetitive sequences at the ends of eukaryotic chromosomes is called ____.

telomerase

An enzyme that can replicate DNA in a damaged region is ______.

Multiple choice question.

DNA polymerase ε

a template repair enzyme

DNA polymerase α

a translesion-replicating polymerase

DNA polymerase δ

a translesion-replicating polymerase

During telomere synthesis the enzyme ____ binds to the 3' overhang region and synthesizes many 6-____ repeats.

telomerase; nucleotide

In eukaryotes, the enzyme ______ removes the RNA primers.

Multiple choice question.

DNA gyrase

MCM helicase

DNA polymerase I

DNA ligase

flap endonuclease

flap endonuclease

Select all that apply

The enzyme telomerase consists of which of the following?

Multiple select question.

RNA

Fatty acids

DNA

Protein subunit

ATP

RNA

Protein subunit

The name for the end of a linear, eukaryotic chromosome is the ____.

telomere

The component of telomerase that enables the enzyme to bind to the telomeric repeat sequence is composed of _____.

Multiple choice question.

DNA

RNA

protein

RNA

Select all that apply

Which characteristics of DNA polymerase prevent the enzyme from replicating the 3' ends of DNA strands?

Multiple select question.

DNA polymerase can only elongate an existing nucleotide strand.

DNA polymerase wraps around the DNA template like a curled hand.

DNA polymerase synthesizes DNA only in a 3' to 5' direction.

DNA polymerase can only catalyze the formation of phosphodiester bonds between nucleotides.

DNA polymerase synthesizes DNA only in a 5' to 3' direction.

DNA polymerase can only elongate an existing nucleotide strand.

DNA polymerase synthesizes DNA only in a 5' to 3' direction.

Telomerase reverse transcriptase is an enzyme that uses a(n) _____ template to produce a(n) ______ strand.

Multiple choice question.

RNA; DNA

RNA; RNA

DNA; RNA

DNA; DNA

RNA; DNA

What is the role of telomerase?

Multiple choice question.

Remove RNA primer flaps created by RNA polymerase I

Prevent the ends of eukaryotic chromosomes from extending

Prevent DNA replication of the centromere region

Prevent the ends of eukaryotic chromosomes from shortening

Prevent the ends of eukaryotic chromosomes from shortening

List the events of telomere synthesis in the correct sequence, putting the first event on top.

Telomerase binds to the 3' overhang region

Telomerase synthesizes a 6-nucleotide repeat

Telomerase shifts and synthesizes many more 6-nucleotide repeats

The complementary strand is made by primase, DNA polymerase, and ligase

1) telomerase binds to the 3' overhang region
2) telomerase synthesizes a 6-nucleotide repeat
3) telomerase shifts and synthesizes many more 6-nucleotide repeats
4) the complementary strand is made by primase, DNA polymerase, and ligase

The enzyme telomerase consists of protein subunits and ____, which is complementary to the DNA sequence in the telomeric repeat.

RNA

True or false: Telomeres remain the same length throughout the lifespan of a cell.

False

Telomerase RNA component ______.

Multiple choice question.

polymerizes DNA to lengthen the telomeres

synthesizes a strand of DNA that is complementary to the lengthened telomeric strand

contains a sequence complementary to the telomeric repeat sequence

contains a sequence complementary to the telomeric repeat sequence

As telomeres of a somatic cell shorten, the cell may become ______, losing the ability to divide.

Multiple choice question.

mature

senescent

unresponsive

quiescent

senescent

The subunits of the enzyme telomerase that are responsible for lengthening the ends of the chromosomes are called telomerase ____ ____.

reverse transcriptase

The ability of cancer cells to continue to divide indefinitely is due to an increase in the activity of the enzyme ______.

Multiple choice question.

DNA ligase

telomerase

DNA gyrase

DNA polymerase α

telomerase

The enzyme that synthesizes the short repetitive sequences at the ends of eukaryotic chromosomes is called ____.

telomerase

In actively dividing cells, telomeres tend to ______ with age.

Multiple choice question.

remain the same

shorten

lengthen

shorten

In somatic cells, telomeres tend to shorten with age. When telomeres are too short, the cells become ____, meaning that they lose their ability to ____.

senescent; divide, duplicate, or reproduce

Many types of cancer cells have an increase in the activity of ______.

Multiple choice question.

telomerase

DNA gyrase

MCM helicase

DNA polymerase α

telomerase