Mastering Biology Chapter 16
A difference between a DNA and an RNA molecule? – answer DNA is double-stranded,
whereas RNA is single-stranded.
(With some exceptions) DNA is a double-stranded molecule and RNA is a single-
stranded molecule.
Nucleotides are composed of - answer a pentose sugar, a nitrogenous base, and a
phosphate group
Phosphate groups contain - answer phosphorus
You can tell that this is an image of a DNA nucleotide and not an RNA nucleotide
because you see a _____. - answer sugar with two, and not three, oxygen atoms
Which of these nitrogenous bases is found in DNA but not in RNA? - answer thymine
DNA contains thymine; RNA does not.
Which letters are purines? – answer AG
Which letters are pyrimidines? – answer CUT
In a nucleotide, the nitrogenous base is attached to the sugar's _____ carbon and the
phosphate group is attached to the sugar's _____ carbon. - answer1' ... 5'
The nitrogenous base is attached to the sugar's 1' carbon and the phosphate group is
attached to the sugar's 5' carbon.
Nucleic acids are assembled in the _____ direction. - answer5' to 3'
New nucleotides are added to the 3' end of a growing polynucleotide.
In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the
complementary strand, and a guanine of one strand always pairs with a(n) _____ of the
complementary strand. - answer thymine ... cytosine
This is referred to as specific base pairing.
In an analysis of the nucleotide composition of DNA, which of the following will be
found? - answerA + C = G + T
, In the Hershey and Chase experiment that helped confirm that DNA, not protein, was
the hereditary material, what was the key finding? - answer Radioactively labeled
phosphorus was present inside the infected bacteria.
When the bacteria had been infected with T2 phage whose DNA was tagged with
radioactive phosphorus, the pellet of mainly bacterial material contained most of the
radioactivity, indicating that the labeled phage DNA had entered the cells.
Which of the following can be determined directly from X-ray diffraction photographs of
crystallized DNA? - answer the diameter of the helix
In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the
complementary strand, and a guanine of one strand always pairs with a(n) _____ of the
complementary strand. - answer thymine ... cytosine
This is referred to as specific base pairing.
After DNA replication is completed, _____. - answer each new DNA double helix
consists of one old DNA strand and one new DNA strand
The first step in the replication of DNA is catalyzed by _____. - answer helicase
The action of helicase creates _____. - answer replication forks and replication bubbles
A replication fork is the transition region between paired and unpaired DNA strands.
Why is the new DNA strand complementary to the 3' to 5' strands assembled in short
segments? – answer DNA polymerase can assemble DNA only in the 5' to 3' direction
Since DNA polymerase can assemble DNA only in the 5' to 3' direction, the new strand
complementary to the 3' to 5' strand must be assembled in short 5' to 3' segments,
which are later joined together by ligase.
The synthesis of a new strand begins with the synthesis of a(n) _____. – answer RNA
primer complementary to a preexisting DNA strand
The synthesis of a DNA strand begins with the formation of an RNA primer.
An old DNA strand is used as a _____ for the assembly of a new DNA strand. - answer
template
An old DNA strand is used as a template for the synthesis of a complementary new
strand.
What catalyzes DNA synthesis? – answer DNA polymerase
A difference between a DNA and an RNA molecule? – answer DNA is double-stranded,
whereas RNA is single-stranded.
(With some exceptions) DNA is a double-stranded molecule and RNA is a single-
stranded molecule.
Nucleotides are composed of - answer a pentose sugar, a nitrogenous base, and a
phosphate group
Phosphate groups contain - answer phosphorus
You can tell that this is an image of a DNA nucleotide and not an RNA nucleotide
because you see a _____. - answer sugar with two, and not three, oxygen atoms
Which of these nitrogenous bases is found in DNA but not in RNA? - answer thymine
DNA contains thymine; RNA does not.
Which letters are purines? – answer AG
Which letters are pyrimidines? – answer CUT
In a nucleotide, the nitrogenous base is attached to the sugar's _____ carbon and the
phosphate group is attached to the sugar's _____ carbon. - answer1' ... 5'
The nitrogenous base is attached to the sugar's 1' carbon and the phosphate group is
attached to the sugar's 5' carbon.
Nucleic acids are assembled in the _____ direction. - answer5' to 3'
New nucleotides are added to the 3' end of a growing polynucleotide.
In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the
complementary strand, and a guanine of one strand always pairs with a(n) _____ of the
complementary strand. - answer thymine ... cytosine
This is referred to as specific base pairing.
In an analysis of the nucleotide composition of DNA, which of the following will be
found? - answerA + C = G + T
, In the Hershey and Chase experiment that helped confirm that DNA, not protein, was
the hereditary material, what was the key finding? - answer Radioactively labeled
phosphorus was present inside the infected bacteria.
When the bacteria had been infected with T2 phage whose DNA was tagged with
radioactive phosphorus, the pellet of mainly bacterial material contained most of the
radioactivity, indicating that the labeled phage DNA had entered the cells.
Which of the following can be determined directly from X-ray diffraction photographs of
crystallized DNA? - answer the diameter of the helix
In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the
complementary strand, and a guanine of one strand always pairs with a(n) _____ of the
complementary strand. - answer thymine ... cytosine
This is referred to as specific base pairing.
After DNA replication is completed, _____. - answer each new DNA double helix
consists of one old DNA strand and one new DNA strand
The first step in the replication of DNA is catalyzed by _____. - answer helicase
The action of helicase creates _____. - answer replication forks and replication bubbles
A replication fork is the transition region between paired and unpaired DNA strands.
Why is the new DNA strand complementary to the 3' to 5' strands assembled in short
segments? – answer DNA polymerase can assemble DNA only in the 5' to 3' direction
Since DNA polymerase can assemble DNA only in the 5' to 3' direction, the new strand
complementary to the 3' to 5' strand must be assembled in short 5' to 3' segments,
which are later joined together by ligase.
The synthesis of a new strand begins with the synthesis of a(n) _____. – answer RNA
primer complementary to a preexisting DNA strand
The synthesis of a DNA strand begins with the formation of an RNA primer.
An old DNA strand is used as a _____ for the assembly of a new DNA strand. - answer
template
An old DNA strand is used as a template for the synthesis of a complementary new
strand.
What catalyzes DNA synthesis? – answer DNA polymerase
