Question 1

Increasing the ion concentration increases the Tm because the ions

Accepted Answer

A)  bind to the phosphate groups of the DNA backbone and increase stability. 
B)  bind to the nucleic acids and disrupt the base pairs, decreasing stability. 
C)  increase the base length of the DNA, increasing stability. 
D)  associate with the ribose sugars, decreasing stability. 
A)  bind to the phosphate groups of the DNA backbone and increase stability. 
B)  bind to the nucleic acids and disrupt the base pairs, decreasing stability. 
C)  increase the base length of the DNA, increasing stability. 
D)  associate with the ribose sugars, decreasing stability.

Question 2

What mediates the binding of histone proteins to DNA?

Accepted Answer

A)  ionic attractions 
B)  London dispersion forces 
C)  hydrophilic interactions 
D)  hydrophobic interactions 
A)  ionic attractions 
B)  London dispersion forces 
C)  hydrophilic interactions 
D)  hydrophobic interactions

Question 3

Genes found in prokaryotes that only contain a single coding sequence are referred to as

Accepted Answer

A)  exons. 
B)  introns. 
C)  polycistronic. 
D)  monocistronic. 
A)  exons. 
B)  introns. 
C)  polycistronic. 
D)  monocistronic.

Question 4

Deletions or insertions into the genome cause a polymorphism called

Accepted Answer

A)  short tandem repeats. 
B)  variable number tandem repeats. 
C)  long tandem repeats. 
D)  single nucleotide polymorphism. 
A)  short tandem repeats. 
B)  variable number tandem repeats. 
C)  long tandem repeats. 
D)  single nucleotide polymorphism.

Question 5

In plasmid transformation, DNA is transferred when

Accepted Answer

A)  bacteriophages infect bacteria. 
B)  foreign DNA fragments are inserted into the plasmid using multiple cloning sites. 
C)  there is a horizontal gene transfer during the bacteria mating process. 
D)  a dead bacterium releases DNA into the environment and it is obtained by another bacterium. 
A)  bacteriophages infect bacteria. 
B)  foreign DNA fragments are inserted into the plasmid using multiple cloning sites. 
C)  there is a horizontal gene transfer during the bacteria mating process. 
D)  a dead bacterium releases DNA into the environment and it is obtained by another bacterium.

Question 6

A double helix that crosses itself in a left-handed twist is referred to as a

Accepted Answer

A)  positive supercoil. 
B)  negative supercoil. 
C)  topoisomer. 
D)  linking number. 
A)  positive supercoil. 
B)  negative supercoil. 
C)  topoisomer. 
D)  linking number.

Question 7

The most common purpose for cloning a gene sequence using mRNA is to

Accepted Answer

A)  disrupt antibiotic resistance. 
B)  determine homologous genomic sequences. 
C)  generate a library of actively transcribed genes. 
D)  disrupt the lacZ gene, resulting in blue-white screening. 
A)  disrupt antibiotic resistance. 
B)  determine homologous genomic sequences. 
C)  generate a library of actively transcribed genes. 
D)  disrupt the lacZ gene, resulting in blue-white screening.

Question 8

When DNA molecules from multiple sources have been connected in the laboratory, the result is referred to as

Accepted Answer

A)  promoters. 
B)  cloning vectors. 
C)  cloning sites. 
D)  recombinant DNA. 
A)  promoters. 
B)  cloning vectors. 
C)  cloning sites. 
D)  recombinant DNA.

Question 9

The K+ ion concentration in a DNA sample is increased from 50 mM to 100 mM. The Tm will

Accepted Answer

A)  remain the same. 
B)  decrease. 
C)  increase. 
D)  vary unpredictably. 
A)  remain the same. 
B)  decrease. 
C)  increase. 
D)  vary unpredictably.

Question 10

Many different genetic variations can be found when comparing the gene sequence of two individuals. Explain three causes of the variations.

Accepted Answer

(1) Single nucleotide polymorphisms are

Question 11

DNA regions rich in A-T are more easily denatured than regions with a higher G-C content. Why is this biologically significant?

Accepted Answer

Regions rich in A-T are often the initia

Question 12

The linking number of a relaxed DNA strand whose axis is not coiling is 30. Predict the twist and writhe of the DNA stand.

Accepted Answer

A)  Wr = 0, Tw = 30 
B)  Wr = 30, Tw = 0 
C)  Wr = 15, Tw = 15 
D)  Wr = 30, Tw = -30 
A)  Wr = 0, Tw = 30 
B)  Wr = 30, Tw = 0 
C)  Wr = 15, Tw = 15 
D)  Wr = 30, Tw = -30

Question 13

In plasmid conjugation, DNA is transferred when

Accepted Answer

A)  bacteriophages infect bacteria. 
B)  foreign DNA fragments are inserted into the plasmid using multiple cloning sites. 
C)  there is a horizontal gene transfer during the bacteria mating process. 
D)  a dead bacterium releases DNA into the environment and it is obtained by another bacterium. 
A)  bacteriophages infect bacteria. 
B)  foreign DNA fragments are inserted into the plasmid using multiple cloning sites. 
C)  there is a horizontal gene transfer during the bacteria mating process. 
D)  a dead bacterium releases DNA into the environment and it is obtained by another bacterium.

Question 14

__________ maintain the length of the chromosome after replication.

Accepted Answer

A)  Telomeres 
B)  Centromeres 
C)  Kinetochores 
D)  Sister chromatids 
A)  Telomeres 
B)  Centromeres 
C)  Kinetochores 
D)  Sister chromatids

Question 15

What are the three ways that RNA and DNA differ?

Accepted Answer

1. RNA has a hydroxyl group on the 2 <su

Question 16

Compare and contrast the steps used to induce a positive supercoil and a negative supercoil.

Accepted Answer

Breaking the phosphodiester bond between

Question 17

Which of the following binds to DNA using a specific sequence?

Accepted Answer

A)  histones 
B)  Lac repressor protein 
C)  double-stranded binding proteins 
D)  single-stranded binding proteins 
A)  histones 
B)  Lac repressor protein 
C)  double-stranded binding proteins 
D)  single-stranded binding proteins

Question 18

Below are the steps involved in cloning gene sequences using mRNA. Arrange the steps in the appropriate order. 1. The double-stranded cDNA is treated with a restriction endonuclease to generate compatible ends for annealing and ligation.
2) mRNA is isolated from the cell and converted back into double-stranded sequences using reverse transcriptase to generate complementary DNA.
3) The RNA-DNA hybrid is treated with a nuclease to cleave the RNA strand, producing RNA fragments.
4) Reverse transcriptase completes the single-stranded cDNA when it reaches the 5 '  end of the mRNA transcript.
5) RNA fragments serve as primers for DNA synthesis of the second strand of cDNA using DNA polymerase.

Accepted Answer

A)  4, 2, 1, 5, 3 
B)  2, 4, 3, 5, 1 
C)  2, 3, 5, 4, 1 
D)  3, 2, 5, 4, 1 
A)  4, 2, 1, 5, 3 
B)  2, 4, 3, 5, 1 
C)  2, 3, 5, 4, 1 
D)  3, 2, 5, 4, 1

Question 19

The figure below shows part of the primary structure of DNA. Identify the nucleoside.

Accepted Answer

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

Question 20

Type II topoisomerase enzymes are important in replication and transcription because they

Accepted Answer

A)  prevent autocleavage. 
B)  prevent DNA cleavage. 
C)  relieve the positive supercoiling. 
D)  stabilize the cleaved complex. 
A)  prevent autocleavage. 
B)  prevent DNA cleavage. 
C)  relieve the positive supercoiling. 
D)  stabilize the cleaved complex.

Exam 3: Nucleic Acid Structure and Function

Increasing the ion concentration increases the Tm because the ions

What mediates the binding of histone proteins to DNA?

Genes found in prokaryotes that only contain a single coding sequence are referred to as

Deletions or insertions into the genome cause a polymorphism called

In plasmid transformation, DNA is transferred when

A double helix that crosses itself in a left-handed twist is referred to as a

The most common purpose for cloning a gene sequence using mRNA is to

When DNA molecules from multiple sources have been connected in the laboratory, the result is referred to as

The K+ ion concentration in a DNA sample is increased from 50 mM to 100 mM. The Tm will

Many different genetic variations can be found when comparing the gene sequence of two individuals. Explain three causes of the variations.

DNA regions rich in A-T are more easily denatured than regions with a higher G-C content. Why is this biologically significant?

The linking number of a relaxed DNA strand whose axis is not coiling is 30. Predict the twist and writhe of the DNA stand.

In plasmid conjugation, DNA is transferred when

__________ maintain the length of the chromosome after replication.

What are the three ways that RNA and DNA differ?

Compare and contrast the steps used to induce a positive supercoil and a negative supercoil.

Which of the following binds to DNA using a specific sequence?

The figure below shows part of the primary structure of DNA. Identify the nucleoside.

Type II topoisomerase enzymes are important in replication and transcription because they

Principles of Biochemistry

Physical Biochemistry: Energy Conversion, Water, and Membranes

Protein Structure

Methods in Protein Biochemistry

Protein Function

Enzyme Mechanisms

Cell Signaling Systems

Glycolysis: a Paradigm of Metabolic Regulation

The Citrate Cycle

Oxidative Phosphorylation

Photosynthesis

Carbohydrate Structure and Function

Carbohydrate Metabolism

Lipid Structure and Function

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Metabolic Integration

DNA Replication, Repair, and Recombination

RNA Synthesis, Processing, and Gene Silencing

Protein Synthesis, Posttranslational Modification, and Transport

Gene Regulation

Filters

Increasing the ion concentration increases the T_m because the ions

The K⁺ion concentration in a DNA sample is increased from 50 mM to 100 mM. The T_m will