Please be patient as the PDF generation may take upto a minute.

For a couple of decades, biologists knew
the nucleus contained DNA and proteins. The
prevailing opinion was that the genetic material
was proteins, and not DNA. The reason for
this belief was that proteins are more complex
than DNA. What was the basis of this
thinking?
1. Proteins have a greater variety of three-
dimensional forms than does DNA.
2. Proteins have two different levels of structural
organization; DNA has four.
3. Proteins are made of 40 amino acids and DNA
is made of four nucleotides.
4. Some viruses only transmit proteins.

What does transformation involve in
Bacteria?
1. assimilation of external DNA into a cell
2. the creation of a strand of DNA from RNA
3. the creation of a strand of RNA from DNA
4. the infection of cells by a phage DNA
molecule

For a science fair project, two students
decided to repeat the Hershey and Chase
experiment, with modifications. They decided to
label the nitrogen of the DNA, rather than
the phosphate. They reasoned that each
nucleotide as only one phosphate and two to
five nitrogens. Thus, labeling the nitrogens
would provide a stronger signal than labeling
the phosphates.Why won't this experiment
work?
1. There is o radioactive isotope of nitrogen.
2. Radioacive nitrogen has a half-life of 100,000
years, and the material would be too
dangerous for too long.
3. Although there are more nitrogens in a
nucleotide, labeled phosphates actually have
16 extra neutrons; therefore, they are more
radioactive.
4.Amino acids (and thus proteins) also have
nitrogen atoms; thus, the radioactivity
would not distinguish between DNA and
proteins.

Cytosine makes up 38% of the
nucleotides in a sample of DNA from an
organism. Approximately what percentage of
the nucleotides in this sample will be thymine?
1. 12
2. 24
3. 31
4. 38

Which of the following can be determined directly from X-ray diffraction photographs of crystallized DNA?
1. the diameter of the helix
2. the rate of replication
3. the sequence of nucleotides
4. the frequency of A vs. T nucleotides

Replication in prokaryotes differs from
replication in eukaryotes for which of these
reasons?
1. The prokaryotic chromosome has histones,
whereas eukaryotic chromosomes do not.
2. Prokaryotic chromosomes have a single origin
of replication, whereas eukaryotic
chromosomes have many.
3. The rate of elongation during DNA
replication is slower in prokaryotes than in
eukaryotes.
4. Prokaryotes produce Okazaki fragments
during DNA replication, but eukaryotes do
not.

Once the pattern found after one round of replication was observed, Meselson and Stahl could be confident of which of the following conclusions?
1. Replication is semi-conservative.
2. Replication is not dispersive.
3. Replication is not semi-conservative.
4. Replication is not conservative.

In E. coli, there is a mutation in a gene called dnaB that alters the helicase that normally acts at the origin. Which of the following would you expect as a result of this mutation?
1. No proofreading will occur.
2. No replication fork will be formed.
3. The DNA will supercoil.
4. Replication will occur via RNA polymerase
alone.

What determines the nucleotide sequence of the newly synthesized strand during DNA replication?
1. the particular DNA polymerase catalyzing the
reaction
2. the relative amounts of the four nucleoside
triphosphates in the cell
3. the nucleotide sequence of the template strand
4. the primase used in the reaction

The difference between ATP and the nucleoside triphosphates used during DNA synthesis is that
1. the nucleoside triphosphates have the sugar
deoxyribose; ATP has the sugar ribose.
2. the nucleoside triphosphates have two
phosphate groups; ATP has three phosphate
groups.
3. ATP contains three high-energy bonds; the
nucleoside triphosphates have two.
4. ATP is found only in human cells; the
nucleoside triphosphates are found in all
animal and plant cells.

Which of the following best describes the addition of nucleotides to a growing DNA chain?
1. A nucleoside triphosphate is added to the 5'
end of the DNA, releasing a molecule of
pyrophosphate.
2. A nucleoside triphosphate is added to the 3'
end of the DNA, releasing a molecule of
pyrophosphate.
3. A nucleoside diphosphate is added to the 5'
end of the DNA, releasing a molecule of
phosphate.
4. A nucleoside diphosphate is added to the 3'
end of the DNA, releasing a molecule of
phosphate.

Which of the following help to hold the DNA strands apart while they are being replicated?
1. primase
2. ligase
3. DNA polymerase
4. single-strand binding proteins

Which would you expect of a eukaryotic cell lacking telomerase?
1. a high probability of becoming cancerous
2. production of Okazaki fragments
3. inability to repair thymine dimers
4. a reduction in chromosome length

Why do histones bind tightly to DNA?
1. Histones are positively charged, and DNA is
negatively charged.
2. Histones are negatively charged, and DNA is
positively charged.
3. Both histones and DNA are strongly
hydrophobic.
4. Histones are covalently linked to the DNA.

What is the basis for the difference in how the leading and lagging strands of DNA molecules are synthesized?
1. The origins of replication occur only at the 5'
end.
2. Helicases and single-strand binding proteins
work at the 5' end.
3. DNA polymerase can join new nucleotides
only to the 3' end of a growing strand.
4. DNA ligase works only in the 3' → 5'
direction.

Using RNA as a template for protein synthesis instead of translating proteins directly from the DNA is advantageous for the cell because
1. RNA is much more stable than DNA.
2. RNA acts as an expendable copy of the
genetic material.
3. only one mRNA molecule can be transcribed
from a single gene, lowering the
potential rate of gene expression.
4. tRNA, rRNA and others are not transcribed.

A mamalian cell typically has 1.2 meters (when completely outstretched) of double stranded DNA.The total time to duplicate the DNA is 5 hours. How many origins of replication are there if the rate of duplication is 16μmeters/min ?
1. 250
2. 15000
3. 1
4. 500

Which of the DNA’s, with the melting points as given, has the highest amount of A-T pairs?
1. 84 C
2. 73 C
3. 69 C
4. 78 C

To form a nucleoside, a nitrogenous base is linked to a pentose sugar:
1. Through a P-Glycosidic linkage at
carbon atom number 1
2. Through a P-Glycosidic linkage at
carbon atom number 5
3. Through a N-Glycosidic linkage at
carbon atom number 1
4. Through a N-Glycosidic linkage at
carbon atom number 5

Transcriptionally active chromatin is termed as:
1. Heterochromatin
2. Euchromatin
3. Prechromatin
4. Prochromatin