Download DNA- HL sample test

Choose the best answer.
What is the function of helicase?
A.
It forms bonds between DNA nucleotides.
B.
It adds new nucleotides to the DNA helix.
C.
It forms the DNA helix.
D.
It separates DNA strands.
What is removed to form mature eukaryotic mRNA?
A.
RNA primers
B.
Exons
C.
RNA polymerases
D.
Introns
What is the composition of the backbone of DNA?
A.
Alternating sugar and phosphate molecules
B.
Complementary base pairs
C.
Alternating sugar and base molecules
D.
A polysaccharide
A certain gene codes for a polypeptide that is 120 amino acids long. Approximately how many
nucleotides long is the mRNA that codes for this polypeptide likely to be?
A.
30
B.
40
C.360
Where do transcription and translation occur in eukaryotic cells?
Transcription
Translation
A.
Cytoplasm
Cytoplasm
B.
Cytoplasm
Mitochondria
C.
Nucleus
Cytoplasm
D.
Nucleus
Nucleus
D. 480
Which of the following are connected by a hydrogen bond?
A.
The hydrogen and oxygen atoms of a water molecule
B.
A base pair of a DNA molecule
C.
Two amino acid molecules of a dipeptide
D.
Two glucose molecules in a disaccharide
The diagram below shows a short section of DNA molecule before and after replication. If the
nucleotides used to replicate the DNA were radioactive, which strands in the replicated molecules
would be radioactive?
I
G C T A C
C G A T G
II
G C T A C
C G A T G
III
G C T A C
C G A T G
IV
A.
II and III only
B.
I and III only
C.
I and II only
D.
I, II, III and IV]
To which parts of the deoxyribose molecule do phosphates bind in DNA?
A.
I and V
B.
III and IV
C.
II and III
D.
III and V
A biochemist isolated and purified molecules needed for DNA replication. When some DNA was
added replication occurred, but the DNA molecules formed were defective. Each consisted
of a normal DNA strand paired with segments of DNA a few hundred nucleotides long.
Which of the following had been left out of the mixture?
A.
DNA ligase
B.
Helicase
C.
Nucleotides
D.
DNA polymerase
What is a difference between the sense and antisense strands of DNA?
A.
Nucleotides are linked to the sense strand by hydrogen bonding during transcription,
but not to the antisense strand.
B.
The sense strand has the same base sequence as tRNA, but the antisense strand does
not.
C.
Nucleotides are linked to the antisense strand by hydrogen bonding during
transcription, but not to the sense strand.
D.
The antisense strand has the same base sequence as mRNA but the sense strand does
not.
During the process of translation which of the following statements describes the relationship
between nucleic acids?
A.
Anticodons on mRNA bind to complementary codons on DNA.
B.
Anticodons on tRNA bind to complementary codons on mRNA.
C.
Bases on DNA bind to complementary bases on mRNA.
D.
A single strand of mRNA is produced from the DNA in the nucleus.
The drawing below shows a short section of a DNA molecule. What is labeled by I, II and III? (
Bonus)
I
II
III
I
II
III
A.
3′ end
purine
hydrogen bond
B.
5′ end
pyrimidine
covalent bond
C.
3′ end
pyrimidine
hydrogen bond
D.
5′ end
purine
covalent bond
How would the following DNA sequence, ACGTTGCATGGCA, be transcribed?
A.
UGCAACGUACCGU
B.
TGCAACGTACCGT
C.
ACGTTGCATGGCA
D.
ACGUUGCAUGGCA
The diagram below represents DNA replication. Some of the bases are indicated.
In which direction is the replication fork moving and which bases would be needed to
replicate the section of DNA shown?
Direction of movement of replication fork
Bases needed
A.
Left to right
U, G and C
B.
Right to left
U, G and C
C.
Left to right
T, G and C
D.
Right to left
T, G and C
Which are the correct directions of the following processes?
Replication
Transcription
Translation
A.
5’ to 3’
3’ to 5’
3’ to 5’
B.
3’ to 5’
5’ to 3’
5’ to 3’
C.
5’ to 3’
5’ to 3’
5’ to 3’
D.
3’ to 5’
3’ to 5’
3’ to 5’
Which stage of translation is illustrated by the diagram below?
A.
Termination
B.
Initiation
C.
Translocation
D.
Elongation
II -Structural factual questions (12 points)
1) The information needed to make polypeptides is carried in the mRNA from the nucleus to the
ribosomes of eukaryotic cells. This information is decoded during translation. The diagram
below represents the process of translation.
(a)
Annotate the diagram to show the direction in which the ribosome moves during
translation.
(1)
(b)
State the name of the next amino acid which will attach to the polypeptide.
..............................................................................................................................
(1)
(c)
Explain how the amino acid was attached to the tRNA.
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(3)
(d)
Identify two locations within a eukaryotic cell where translation occurs.
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(1)
(Total 6 marks)
2-The following diagram represents replication in DNA.
A
B
[Freeman, Scott, Biological Science, 1st,  2002. Electronically reproduced by permission of Pearson Education, Inc.,
Upper Saddle River, New Jersey]
(a)
State the name and describe the function for the enzymes labelled A and B on the
diagram.
(i)
(ii)
A:
B:
Name:
..........................................................................................
Function:
..........................................................................................
Name:
..........................................................................................
Function:
..........................................................................................
(2)
(b)
Identify the cellular location of DNA replication in eukaryotic cells.
..............................................................................................................................
(1)
(c)
State at which period during the cell cycle DNA replication occurs.
..............................................................................................................................
(1)
(d)
Explain the significance of complementary base pairing during DNA replication.
..............................................................................................................................
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(2)
III-Data base questions ( 11 marks)
1- It had always been assumed that eukaryotic genes were similar in organization to prokaryotic
genes. However, modern techniques of molecular analysis indicated that there are
additional DNA sequences that lie within the coding region of genes. Exons are the DNA
sequences that code for proteins while introns are the intervening sequences that have to be
removed. The graph shows the number of exons found in genes for three different groups
of eukaryotes.
Percentage of genes
100
80
Saccharomyces cerevisiae (a yeast)
60
40
20
0
40
30
Drosophila melanogaster (fruit fly)
20
10
0
20
15
Mammals
10
5
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 <30<40<60>60
Number of exons
[Source: Benjamin Lewin, (1999) Genes VII, OUP, page 55]
(a)
Calculate the percentage of genes that have five or less exons in mammals.
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
Describe the distribution of the number of exons and the percentage of genes in
D. melanogaster.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
(i)
Compare the distributions of the number of exons found in genes of S.
cerevisiae and mammals.
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...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Suggest one reason for the differences in the numbers of exons found in genes
of
S. cerevisiae and mammals.
...........................................................................................................................
...........................................................................................................................
(1)
2- The figure below represents the process and the results of the experiment done by Hershey
and Chase.
a) Where was the radioactive material found? ( 1)
...........................................................................................................................
b) Explain why the genetic material should be found in that location. (2)
...........................................................................................................................
...........................................................................................................................
c) Discuss whether the evidence that DNA is the chemical which transforms the bacterial into
infected cells.( 2)
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III- Extended response. (14 marks)
1- Discuss the differences between the processes of transcription and translation.
(4marks)
2- Outline how gene expression is regulated in Prokaryotes and Eukaryotes. ( 3 marks)
3- a) Define gene mutation. (2 marks)
b) Sickle cell anemia is a serious disease caused by a single base substitution mutation. Explain
how a single base substitution mutation can have significant consequences for an
individual.
(5 marks)