Question 1

Which factor distinguishes bacterial topoisomerase III from topoisomerase IB?

Accepted Answer

A)   consumption of ATP
B)   cleavage of one or two strands
C)   relaxing or increasing the amount of supercoiling
D)   the mechanism of action
E)   amino acid involved in covalent attachment to nucleic acidF) B) and C)
G) All of the above

Question 2

Which aspect does NOT distinguish bacterial SMC proteins from eukaryotic SMC proteins?

Accepted Answer

A)  formation of coiled-coil structures
B)  binding and hydrolysis of ATP
C)  formation of "hinge" domains
D)  formation of "head" domains
E)  formation of homodimers versus heterodimersF) A) and E)
G) A) and D)

Question 3

Define "specific linking difference" ($\sigma$), also called superhelical density.

Accepted Answer

The "specific linking difference," also ...

Question 4

How many nucleosomes would you expect to find in a 1,000 bp piece of linear DNA?

Accepted Answer

A)   zero to one
B)   two to three
C)   four to five
D)   six to seven
E)   eight to nineF) D) and E)
G) A) and B)

Question 5

SMC proteins facilitate the structural maintenance of chromosomes; describe the roles of the two main classes.

Accepted Answer

The two main classes of SMC proteins are...

Question 6

DNA in a closed-circular, double-stranded molecule with no net bending of the DNA axis on itself is:

Accepted Answer

A)   a left-handed helix.
B)   a mixed right- and left-handed helix.
C)   relaxed.
D)   supercoiled.
E)   underwound.F) B) and E)
G) A) and D)

Question 7

Bacterial plasmids:

Accepted Answer

A)   are always covalently joined to the bacterial chromosome.
B)   are composed of RNA.
C)   are never circular.
D)   cannot replicate when cells divide.
E)   often encode proteins not normally essential to the bacterium's survival.F) None of the above
G) C) and D)

Question 8

The eukaryotic SMC protein condensin contains which SMC subunits?

Accepted Answer

A)   SMC1 and SMC2
B)   SMC1 and SMC3
C)   SMC2 and SMC3
D)   SMC2 and SMC4
E)   SMC3 and SMC4F) C) and E)
G) A) and B)

Question 9

Which statement is TRUE for histones?

Accepted Answer

A)   They vary in size from 200 to 400 amino acids in length.
B)   They form covalent complexes with DNA.
C)   They form both protein:DNA and protein:protein interactions.
D)   They contain large amounts of Asp residues.
E)   DNA wraps around them in a right-handed helical structure.F) A) and D)
G) B) and D)

Question 10

Which protein carries out ATP hydrolysis?

Accepted Answer

A)   histone H2A
B)   histone H1
C)   E. coli topoisomerase I
D)   condensin
E)   E. coli topoisomerase IIIF) C) and D)
G) A) and D)

Question 11

In which phase of the cell cycle is DNA MOST condensed?

Accepted Answer

A)   G1 phase
B)   S phase
C)   G2 phase
D)   prophase
E)   metaphaseF) None of the above
G) All of the above

Question 12

Plectonemic supercoils in a negatively supercoiled DNA molecule:

Accepted Answer

A)   are always left-handed.
B)   are always right-handed.
C)   are balanced by solenoidal supercoils
D)   can be either right- or left-handed.
E)   never occur.F) A) and C)
G) None of the above

Question 13

Introns:

Accepted Answer

A)   are frequently present in prokaryotic genes but are rare in eukaryotic genes.
B)   are spliced out before transcription.
C)   are translated but not transcribed.
D)   can occur many times within a single gene.
E)   encode unusual amino acids in proteins.F) B) and C)
G) A) and E)

Question 14

An average base pair in DNA is 650 Da. Histone masses are shown in the table. What is the approximate mass of a nucleosome core in kiloDaltons (kDa) ? Histone
Mass (Daltons) 
Histone H1
21,130
Histone H2A
13,960
Histone H2B
13,774
Histone H3
15,273
Histone H4
11,236

Accepted Answer

A)   ~55 kDa
B)   ~75 kDa
C)   ~170 kDa
D)   ~205 kDa
E)   ~230 kDaF) B) and E)
G) A) and B)

Question 15

The genome of organism A is 4.6 million base pairs long, while that of organism B is 12.1 million base pairs long. Given this information, what can be stated regarding these two organisms?

Accepted Answer

A)   Organism B will contain approximately three times the number of genes as organism A.
B)   Organism B will contain approximately 7.5 million more base pairs in introns compared with organism A.
C)   Organism B will contain three times as many chromosomes as organism A.
D)   All of the statements are valid.
E)   None of the statements is valid.F) B) and D)
G) A) and C)

Question 16

The SMC proteins (for structural maintenance of chromosomes)  include cohesins and condensins and are NOT known to have:

Accepted Answer

A)   a complete ATP binding site.
B)   a hinge region.
C)   topoisomerase activity to produce positive supercoils.
D)   the ability to condense DNA.
E)   two coiled-coil domains.F) D) and E)
G) A) and B)

Question 17

A commonality between type I and type II topoisomerases is that they both:

Accepted Answer

A)   change the linking number in increments of 1 or 2.
B)   require ATP.
C)   go through a mechanism using a covalent enzyme-substrate intermediate.
D)   are inhibited by quinoline antibiotics.
E)   All of the answers are correct.F) A) and E)
G) A) and C)

Question 18

Which elements are NOT necessary to make a stable yeast artificial chromosome (YAC) ?

Accepted Answer

A)   centromeres
B)   replication origins
C)   satellite DNA sequences
D)   telomeres
E)   All of these are required to make a stable YAC.F) C) and D)
G) B) and E)

Question 19

Which protein is NOT important in the compaction of eukaryotic DNA?

Accepted Answer

A)   histone H1
B)   cohesins
C)   condensins
D)   topoisomerases
E)   HU proteinsF) B) and D)
G) A) and B)

Exam 24: Genes and Chromosomes

Which protein carries out ATP hydrolysis?

Correct Answer
verified

Which statement is TRUE for histones?

Correct Answer
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DNA in a closed-circular, double-stranded molecule with no net bending of the DNA axis on itself is:

Correct Answer
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Which elements are NOT necessary to make a stable yeast artificial chromosome (YAC) ?

Correct Answer
verified

Bacterial plasmids:

Correct Answer
verified

The eukaryotic SMC protein condensin contains which SMC subunits?

Correct Answer
verified

Plectonemic supercoils in a negatively supercoiled DNA molecule:

Correct Answer
verified

Define "specific linking difference" ( $\sigma$ ), also called superhelical density.

Correct Answer
Answered by ExamLex AI
The "specific linking difference," also ...
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Which protein is NOT important in the compaction of eukaryotic DNA?

Correct Answer
verified

A commonality between type I and type II topoisomerases is that they both:

Correct Answer
verified

How many nucleosomes would you expect to find in a 1,000 bp piece of linear DNA?

Correct Answer
verified

In which phase of the cell cycle is DNA MOST condensed?

Correct Answer
verified

Which factor distinguishes bacterial topoisomerase III from topoisomerase IB?

Correct Answer
verified

The genome of organism A is 4.6 million base pairs long, while that of organism B is 12.1 million base pairs long. Given this information, what can be stated regarding these two organisms?

Correct Answer
verified

An average base pair in DNA is 650 Da. Histone masses are shown in the table. What is the approximate mass of a nucleosome core in kiloDaltons (kDa) ? Histone Mass (Daltons) Histone H1 21,130 Histone H2A 13,960 Histone H2B 13,774 Histone H3 15,273 Histone H4 11,236

Correct Answer
verified

The SMC proteins (for structural maintenance of chromosomes) include cohesins and condensins and are NOT known to have:

Correct Answer
verified

Which aspect does NOT distinguish bacterial SMC proteins from eukaryotic SMC proteins?

Correct Answer
Answered by ExamLex AI

Introns:

Correct Answer
verified

SMC proteins facilitate the structural maintenance of chromosomes; describe the roles of the two main classes.

Correct Answer
Answered by ExamLex AI
The two main classes of SMC proteins are...
View Answer

Exam 24: Genes and Chromosomes

Which protein carries out ATP hydrolysis?

Correct AnswerverifiedShow Answer

Which statement is TRUE for histones?

Correct AnswerverifiedShow Answer

DNA in a closed-circular, double-stranded molecule with no net bending of the DNA axis on itself is:

Correct AnswerverifiedShow Answer

Which elements are NOT necessary to make a stable yeast artificial chromosome (YAC) ?

Correct AnswerverifiedShow Answer

Bacterial plasmids:

Correct AnswerverifiedShow Answer

The eukaryotic SMC protein condensin contains which SMC subunits?

Correct AnswerverifiedShow Answer

Plectonemic supercoils in a negatively supercoiled DNA molecule:

Correct AnswerverifiedShow Answer

Define "specific linking difference" ( σ\sigmaσ ), also called superhelical density.

Correct AnswerAnswered by ExamLex AIThe "specific linking difference," also ...View AnswerShow Answer

Which protein is NOT important in the compaction of eukaryotic DNA?

Correct AnswerverifiedShow Answer

A commonality between type I and type II topoisomerases is that they both:

Correct AnswerverifiedShow Answer

How many nucleosomes would you expect to find in a 1,000 bp piece of linear DNA?

Correct AnswerverifiedShow Answer

In which phase of the cell cycle is DNA MOST condensed?

Correct AnswerverifiedShow Answer

Which factor distinguishes bacterial topoisomerase III from topoisomerase IB?

Correct AnswerverifiedShow Answer

The genome of organism A is 4.6 million base pairs long, while that of organism B is 12.1 million base pairs long. Given this information, what can be stated regarding these two organisms?

Correct AnswerverifiedShow Answer

An average base pair in DNA is 650 Da. Histone masses are shown in the table. What is the approximate mass of a nucleosome core in kiloDaltons (kDa) ? Histone Mass (Daltons) Histone H1 21,130 Histone H2A 13,960 Histone H2B 13,774 Histone H3 15,273 Histone H4 11,236

Correct AnswerverifiedShow Answer

The SMC proteins (for structural maintenance of chromosomes) include cohesins and condensins and are NOT known to have:

Correct AnswerverifiedShow Answer

Which aspect does NOT distinguish bacterial SMC proteins from eukaryotic SMC proteins?

Correct AnswerAnswered by ExamLex AIShow Answer

Introns:

Correct AnswerverifiedShow Answer

SMC proteins facilitate the structural maintenance of chromosomes; describe the roles of the two main classes.

Correct AnswerAnswered by ExamLex AIThe two main classes of SMC proteins are...View AnswerShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
verified

Define "specific linking difference" ( $\sigma$ ), also called superhelical density.

Correct Answer
Answered by ExamLex AI
The "specific linking difference," also ...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
Answered by ExamLex AI

Correct Answer
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Correct Answer
Answered by ExamLex AI
The two main classes of SMC proteins are...
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