Question 1

How are the telomeric regions on the ends of the linear eukaryotic chromosomes preserved during replication?

Accepted Answer

Telomerase recognizes the G-rich telomer

Question 2

When John Cairns first visualized the replication of E.coli chromosomes in 1963 what did he conclude? 1.The chromosomes of E.coli are circular structures that exist as u-shaped intermediates during replication.
2)The unwinding of the two complementary parental strands and their semiconservative replication occur simultaneously or are closely coupled.
3)Semiconservative replication of the E.coli chromosome started at a specific site,and proceeded sequentially and unidirectionally around the circular structure

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  All of these 
A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  All of these

Question 3

Which of the following does not replicate in a bidirectional format?

Accepted Answer

A)  Lambda phage 
B)  E. coli 
C)  SV40 
D)  Coliphage P2 
E)  All of these replicate bidirectionally 
A)  Lambda phage 
B)  E. coli 
C)  SV40 
D)  Coliphage P2 
E)  All of these replicate bidirectionally

Question 4

Which of the following statements is not true regarding DNA replication?

Accepted Answer

A)  DNA replication occurs in a semi-conservative manner. 
B)  DNA replication begins at unique initiation points 
C)  DNA replication proceeds bidirectionally from the initiation point. 
D)  DNA replication proceeds in one direction from the initiation point. 
E)  All of these are false 
A)  DNA replication occurs in a semi-conservative manner. 
B)  DNA replication begins at unique initiation points 
C)  DNA replication proceeds bidirectionally from the initiation point. 
D)  DNA replication proceeds in one direction from the initiation point. 
E)  All of these are false

Question 5

Which of the following statements about telomerase are true: 1.It extends the 3' end of a linear chromosome one repeat at a time.
2)It uses a built-in DNA to act as a template for synthesis of the telomeric repeat.
3)Without telomerase,linear chromosomes would become progressively shorter.

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  1 and 3 
A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  1 and 3

Question 6

In the E.coli chromosome the origin of replication,called oriC,is characterized as being rich in:

Accepted Answer

A)  A-T base pairs 
B)  A-G base pairs 
C)  C-G base pairs 
D)  C-T base pairs 
E)  G-T base pairs 
A)  A-T base pairs 
B)  A-G base pairs 
C)  C-G base pairs 
D)  C-T base pairs 
E)  G-T base pairs

Question 7

The idea that eukaryotic chromosomes replicate semiconservatively was supported by Taylor et al,in experiments using ³H-thymidine labeled DNA from ______:

Accepted Answer

A)  E. coli , and saw that the DNA was of intermediate density after one round of replication 
B)  Vicia faba, and saw that only one of the chromatids of each pair was radioactive after a second round of c-metaphase. 
C)  Vicia faba , and saw that only one of the chromatids of each pair was radioactive after a single round of c-metaphase. 
D)  E. coli , and saw that the DNA was of light density after one round of replication 
E)  None of these 
A)  E. coli , and saw that the DNA was of intermediate density after one round of replication 
B)  Vicia faba, and saw that only one of the chromatids of each pair was radioactive after a second round of c-metaphase. 
C)  Vicia faba , and saw that only one of the chromatids of each pair was radioactive after a single round of c-metaphase. 
D)  E. coli , and saw that the DNA was of light density after one round of replication 
E)  None of these

Question 8

Since the parental double helix must rotate 360° to unwind each gyre of the helix,during the semi-conservative replication of the bacterial chromosome,some kind of "swivel" must exist.What do geneticists now know that the required swivel is?

Accepted Answer

A)  Topoisomerase 
B)  Helicase 
C)  A transient single-strand break produced by the action of topoisomerases 
D)  A transient single-strand break produced by the action of helicases 
E)  A transient single-strand break produced by the action of Ligase 
A)  Topoisomerase 
B)  Helicase 
C)  A transient single-strand break produced by the action of topoisomerases 
D)  A transient single-strand break produced by the action of helicases 
E)  A transient single-strand break produced by the action of Ligase

Question 9

The RNA containing enzyme that participates in the addition of the telomeric ends of the chromosome is known as:

Accepted Answer

A)  Replicase 
B)  Gyrase 
C)  Telomerase 
D)  Ligase 
E)  Polymerase V 
A)  Replicase 
B)  Gyrase 
C)  Telomerase 
D)  Ligase 
E)  Polymerase V

Question 10

Which of the following prokaryotic replication events is incorrect?

Accepted Answer

A)  Interaction of prepriming proteins with oriC, such as DnaA, DnaB, and DnaC. 
B)  Initiation of Okazaki fragments on the lagging strand carried out by the primosome, a protein complex of primase and DNA helicase. 
C)  RNA primers are covalently extended with deoxynucleotides by Pol I 
D)  The replisome contains two Pol III holoenzymes, one for the leading and one for lagging strands. 
E)  Only one of the two Pol III holoenzymes contains a primosome. 
A)  Interaction of prepriming proteins with oriC, such as DnaA, DnaB, and DnaC. 
B)  Initiation of Okazaki fragments on the lagging strand carried out by the primosome, a protein complex of primase and DNA helicase. 
C)  RNA primers are covalently extended with deoxynucleotides by Pol I 
D)  The replisome contains two Pol III holoenzymes, one for the leading and one for lagging strands. 
E)  Only one of the two Pol III holoenzymes contains a primosome.

Question 11

E.coli chromosomes:

Accepted Answer

A)  Replicate in a unidirectional pattern from a single, unique origin, called oriC. 
B)  Adopt a u-shaped conformation during replication. 
C)  Consist of two Y-shaped replication forks which move in same direction 
D)  Have AT-rich regions at the origin of replication to maintain a tight conformation between strands, this facilitates the formation of the replication bubble. 
E)  None of these 
A)  Replicate in a unidirectional pattern from a single, unique origin, called oriC. 
B)  Adopt a u-shaped conformation during replication. 
C)  Consist of two Y-shaped replication forks which move in same direction 
D)  Have AT-rich regions at the origin of replication to maintain a tight conformation between strands, this facilitates the formation of the replication bubble. 
E)  None of these

Question 12

Which of the following enzymes catalyzes DNA synthesis?

Accepted Answer

A)  DNA Ligase 
B)  DNA Helicase 
C)  DNA Polymerase 
D)  DNA Gyrase 
E)  None of these 
A)  DNA Ligase 
B)  DNA Helicase 
C)  DNA Polymerase 
D)  DNA Gyrase 
E)  None of these

Question 13

In eukaryotes,two DNA polymerases were found to be essential to leading and lagging strand synthesis of the SV40 virus.They are:

Accepted Answer

A)    
B)    
C)    
D)    
E)   
A)    
B)    
C)    
D)    
E)

Question 14

Briefly compare the origins of replication in bacterial chromosomes and eukaryotic chromosomes?

Accepted Answer

In bacterial and viral chromosomes,there

Question 15

In order for DNA to replicate in a semi-conservative manner,what must occur? 1.The double stranded parent DNA molecule must be separated by breaking the hydrogen bonds between the nitrogenous bases
2)Both parent strands of DNA must serve as a template for the synthesis of the new strands
3)The parent strands of DNA must re-anneal after serving as a template for the synthesis of new DNA.

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  2 and 3 
A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  2 and 3

Question 16

Consider the replicated strand of DNA: 3'-ATCGGGAAATTCGGA-5 .' Which of the following choices shows the template strand of DNA used for replication?

Accepted Answer

A)  3'---ATCGGGAAATTCGGA-5' 
B)  5'---ATCGGGAAATTCGGA---3' 
C)  3'---TAGCCCTTTAAGCCT---5'. 
D)  3'---TAGCCCTTTAAGCCT---5'.. 
E)  5'---UAGCCCUUUAAGCCU---3' 
A)  3'---ATCGGGAAATTCGGA-5' 
B)  5'---ATCGGGAAATTCGGA---3' 
C)  3'---TAGCCCTTTAAGCCT---5'. 
D)  3'---TAGCCCTTTAAGCCT---5'.. 
E)  5'---UAGCCCUUUAAGCCU---3'

Question 17

Briefly explain the mechanism for rolling circle replication.

Accepted Answer

As the name implies,rolling-circle repli

Question 18

The 3' 5' exonuclease activities of DNA polymerases read nascent strands as they are synthesized,removing any mispaired nucleotides at the 3¢ termini of primer strands.This action is known as:

Accepted Answer

A)  Rereading 
B)  Proofreading 
C)  Editing 
D)  Splicing 
E)  Lysing 
A)  Rereading 
B)  Proofreading 
C)  Editing 
D)  Splicing 
E)  Lysing

Question 19

Proofreading activities of E.coli DNA polymerases is carried out by:

Accepted Answer

A)  Polymerase I by the 3' 5' exonuclease activity 
B)  Polymerase I by the 5' 3' exonuclease activity 
C)  Polymerase III by the 3' 5' exonuclease activity 
D)  Polymerase III by the 5' 3' exonuclease activity 
E)  Polymerase IV by the 5' 3' endonuclease activity 
A)  Polymerase I by the 3' 5' exonuclease activity 
B)  Polymerase I by the 5' 3' exonuclease activity 
C)  Polymerase III by the 3' 5' exonuclease activity 
D)  Polymerase III by the 5' 3' exonuclease activity 
E)  Polymerase IV by the 5' 3' endonuclease activity

Question 20

The work of Meselson and Stahl:

Accepted Answer

A)  Showed that DNA replication semiconservative, which means that the parental double helix is conserved. 
B)  Used the radioisotope ³H-thymidine in conjunction with centrifugation to separate DNA on the basis of size 
C)  Showed that the DNA, after one round of replication, was of intermediate density thereby showing that the DNA molecules contained one parent strand and one new strand. 
D)  All of these 
E)  None of these 
A)  Showed that DNA replication semiconservative, which means that the parental double helix is conserved. 
B)  Used the radioisotope ³H-thymidine in conjunction with centrifugation to separate DNA on the basis of size 
C)  Showed that the DNA, after one round of replication, was of intermediate density thereby showing that the DNA molecules contained one parent strand and one new strand. 
D)  All of these 
E)  None of these

Exam 10: Replication Of DNA And Chromosomes

How are the telomeric regions on the ends of the linear eukaryotic chromosomes preserved during replication?

Which of the following does not replicate in a bidirectional format?

Which of the following statements is not true regarding DNA replication?

Which of the following statements about telomerase are true: 1.It extends the 3' end of a linear chromosome one repeat at a time. 2)It uses a built-in DNA to act as a template for synthesis of the telomeric repeat. 3)Without telomerase,linear chromosomes would become progressively shorter.

In the E.coli chromosome the origin of replication,called oriC,is characterized as being rich in:

The idea that eukaryotic chromosomes replicate semiconservatively was supported by Taylor et al,in experiments using ³H-thymidine labeled DNA from ______:

Since the parental double helix must rotate 360° to unwind each gyre of the helix,during the semi-conservative replication of the bacterial chromosome,some kind of "swivel" must exist.What do geneticists now know that the required swivel is?

The RNA containing enzyme that participates in the addition of the telomeric ends of the chromosome is known as:

Which of the following prokaryotic replication events is incorrect?

E.coli chromosomes:

Which of the following enzymes catalyzes DNA synthesis?

In eukaryotes,two DNA polymerases were found to be essential to leading and lagging strand synthesis of the SV40 virus.They are:

Briefly compare the origins of replication in bacterial chromosomes and eukaryotic chromosomes?

Consider the replicated strand of DNA: 3'-ATCGGGAAATTCGGA-5 .' Which of the following choices shows the template strand of DNA used for replication?

Briefly explain the mechanism for rolling circle replication.

The 3'5' exonuclease activities of DNA polymerases read nascent strands as they are synthesized,removing any mispaired nucleotides at the 3¢ termini of primer strands.This action is known as:

Proofreading activities of E.coli DNA polymerases is carried out by:

The work of Meselson and Stahl:

The Science Of Genetics

Cellular Reproduction

Mendelism The Basic Principles Of Inheritance

Extensions Of Mendelism

The Chromosomal Basis Of Mendelism

Variation In Chromosome Number And Structure

Linkage,Crossing Over,And Chromosome Mapping In …

The Genetics Of Bacteria And Their Viruses

DNA And The Molecular Structure Of Chromosomes

Transcription And RNA Processing

Translation And The Genetic Code

Mutation,DNA Repair,And Recombination

The Techniques Of Molecular Genetics

Genomics

Applications Of Molecular Genetics

Transposable Genetics Elements

Regulation Of Gene Expression In Prokaryotes

Regulation Of Gene Expression In Eukaryotes

The Genetic Control Of Animal Development

The Genetic Basis Of Cancer

Inheritance Of Complex Traits

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