Bio Sci 99 quizzes Questions and Answers
Question 1.
What is the difference between exonucleases and endonucleases?
Correct Answer: Exo cuts the ends of DNA strands, endo cuts internally.
Question 2.
Watson and Crick proposed that during DNA replication, the double strand is unwound and
each parental strand is used as a template to generate a new daughter strand. The new
and old strands then form a new DNA helix. What is this mode of replication called?
Correct Answer: semi-conservative replication
Question 3.
Arthur Kornberg's group found that in vitro DNA replication required all four dNTPs. What
conclusion did they arrive at based on this result?
Correct Answer: The DNA synthesis enzyme must be using a DNA strand as a
template for synthesis.
Question 4.
Imagine Hershey/Chase had used an RNA virus (genome composed of RNA) instead of a
DNA virus in their experiment. Would radioactivity still have been found in the pellet?
Correct Answer: Yes, because DNA and RNA nucleotides are similar.
Question 5.
Which of the following is the correct order of the enzymes used during replication?
Correct Answer: -Helicase, Primase, DNA polymerase, Ribonuclease H, DNA
ligase
Question 6.
The human genome is mostly composed of: (270)
Correct Answer: Transposons and retrotransposons that are mostly inactive.
Question 7.
Observing replication of circular plasmid DNAs by electron microscopy show that:
Correct Answer: Replication initiates from a single origin, creating two
replication forks that move in opposite directions.
Question 8.
Which of the following are true regarding nucleic acid hybridization?
Correct Answer: -It is possible to visualize a region of genomic DNA using a
fluorescent probe. - It is possible to hybridize a DNA strand to an RNA strand. - It
is possible for DNA from different species to hybridize.
Question 9.
The carbons of the pentose group of DNA and RNA nucleotides are identical except for:
Correct Answer: A. The functional group attached to C1 B. The functional group
attached to C2 C. The functional group attached to C3 D. The functional group
attached to C4 E. The functional group attached to C5 = B because RNA has an
OH on C2 while DNA does not have an OH on C2
, Question 10.
Choose the answer that has the information flow of the central dogma in the correct order.
Correct Answer: DNA, transcription, RNA, translation, protein
Question 11.
A deoxyribonucleotide is composed of:
Correct Answer: A. Nitrogenous Base B. Ribose C. Phosphate group D. Pentose
with 3' OH = Nitrogenous Base, Phosphate Group, Pentose with 3' OH
Question 12.
In the following pathway, mutation of enzyme II would result in the accumulation of
__________ and the mutant would require __________ in the media in order to grow.
Correct Answer: ornithine, citrulline
Question 13.
DNA/RNA is the less stable molecule because:
Correct Answer: DNA, because it has a 2' H group
Question 14.
Which base is found in both DNA and RNA?
Correct Answer: A. Uracil B. Thymine C. Guanine C. Guanine
Question 15.
Which of the following does not describe an aspect of the Human Genome Project?
Correct Answer: -Overlapping clones from YAC and BAC libraries were identified
by hybridization and organized into long contiguous stretches called contigs.
-Landmark sequences on the contig called sequence tagged sites (STS) were
used to aid in ordering the contigs. -The contigs were sequenced using a
shotgun method, and the resulting sequences were assembled by computer.
Question 16.
Which of the following is necessary for a DNA synthesis reaction catalyzed by DNA
polymerase? Select all that apply.
Correct Answer: -Template DNA -RNA primer -dNTPs
Question 17.
Why is there a problem replicating the ends of linear DNA?
Correct Answer: The primer used for lagging strand synthesis can't be replaced
because there is no available 3' OH to add the replacement DNA on to.
Question 18.
Genomics is the field dedicated to the study of: (260)
Correct Answer: -DNA on a cellular scale.
Question 19.
An appropriate dNTP forms a hydrogen bond with an exposed base on the template strand.
The next dNTP forms a bond between the 3' OH group of the 1st nucleotide and the 5'
phosphate of the 2nd nucleotide. The enzyme responsible for catalyzing formation of this
bond is:
Correct Answer: DNA polymerase
Question 1.
What is the difference between exonucleases and endonucleases?
Correct Answer: Exo cuts the ends of DNA strands, endo cuts internally.
Question 2.
Watson and Crick proposed that during DNA replication, the double strand is unwound and
each parental strand is used as a template to generate a new daughter strand. The new
and old strands then form a new DNA helix. What is this mode of replication called?
Correct Answer: semi-conservative replication
Question 3.
Arthur Kornberg's group found that in vitro DNA replication required all four dNTPs. What
conclusion did they arrive at based on this result?
Correct Answer: The DNA synthesis enzyme must be using a DNA strand as a
template for synthesis.
Question 4.
Imagine Hershey/Chase had used an RNA virus (genome composed of RNA) instead of a
DNA virus in their experiment. Would radioactivity still have been found in the pellet?
Correct Answer: Yes, because DNA and RNA nucleotides are similar.
Question 5.
Which of the following is the correct order of the enzymes used during replication?
Correct Answer: -Helicase, Primase, DNA polymerase, Ribonuclease H, DNA
ligase
Question 6.
The human genome is mostly composed of: (270)
Correct Answer: Transposons and retrotransposons that are mostly inactive.
Question 7.
Observing replication of circular plasmid DNAs by electron microscopy show that:
Correct Answer: Replication initiates from a single origin, creating two
replication forks that move in opposite directions.
Question 8.
Which of the following are true regarding nucleic acid hybridization?
Correct Answer: -It is possible to visualize a region of genomic DNA using a
fluorescent probe. - It is possible to hybridize a DNA strand to an RNA strand. - It
is possible for DNA from different species to hybridize.
Question 9.
The carbons of the pentose group of DNA and RNA nucleotides are identical except for:
Correct Answer: A. The functional group attached to C1 B. The functional group
attached to C2 C. The functional group attached to C3 D. The functional group
attached to C4 E. The functional group attached to C5 = B because RNA has an
OH on C2 while DNA does not have an OH on C2
, Question 10.
Choose the answer that has the information flow of the central dogma in the correct order.
Correct Answer: DNA, transcription, RNA, translation, protein
Question 11.
A deoxyribonucleotide is composed of:
Correct Answer: A. Nitrogenous Base B. Ribose C. Phosphate group D. Pentose
with 3' OH = Nitrogenous Base, Phosphate Group, Pentose with 3' OH
Question 12.
In the following pathway, mutation of enzyme II would result in the accumulation of
__________ and the mutant would require __________ in the media in order to grow.
Correct Answer: ornithine, citrulline
Question 13.
DNA/RNA is the less stable molecule because:
Correct Answer: DNA, because it has a 2' H group
Question 14.
Which base is found in both DNA and RNA?
Correct Answer: A. Uracil B. Thymine C. Guanine C. Guanine
Question 15.
Which of the following does not describe an aspect of the Human Genome Project?
Correct Answer: -Overlapping clones from YAC and BAC libraries were identified
by hybridization and organized into long contiguous stretches called contigs.
-Landmark sequences on the contig called sequence tagged sites (STS) were
used to aid in ordering the contigs. -The contigs were sequenced using a
shotgun method, and the resulting sequences were assembled by computer.
Question 16.
Which of the following is necessary for a DNA synthesis reaction catalyzed by DNA
polymerase? Select all that apply.
Correct Answer: -Template DNA -RNA primer -dNTPs
Question 17.
Why is there a problem replicating the ends of linear DNA?
Correct Answer: The primer used for lagging strand synthesis can't be replaced
because there is no available 3' OH to add the replacement DNA on to.
Question 18.
Genomics is the field dedicated to the study of: (260)
Correct Answer: -DNA on a cellular scale.
Question 19.
An appropriate dNTP forms a hydrogen bond with an exposed base on the template strand.
The next dNTP forms a bond between the 3' OH group of the 1st nucleotide and the 5'
phosphate of the 2nd nucleotide. The enzyme responsible for catalyzing formation of this
bond is:
Correct Answer: DNA polymerase
