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Chapter 29
Applied genetics
Multiple-choice questions
1.
What conclusion can be made from the following evidence from an analysis of
woman
child II
child I
man
DNA fragments?
A
Both children are related to both parents.
B
Child I is related to the man but child II is not.
C
Both children are unrelated to either of the parents.
D
Child II is related to the man but child I is not.
IB Biology Standard Level Paper 1 (TZ1) May 2009 Q18
2.
What could be achieved by DNA profiling using gel electrophoresis?
A
The chromosome number of an organism could be counted.
B
It could be shown that human tissue found at the site of a crime did not
come from a person suspected of having committed the crime.
C
A karyotype could be produced.
D
Extinct species of living organisms could be brought back to life.
IB Biology Standard Level Paper 1 (TZ2) May 2009 Q26
1
3.
The diagram below shows the result of a DNA profile of samples collected from
two crime scenes and four suspects.
Which suspect was present at both crime scenes?
crime
crime suspect suspect suspect suspect
scene 1 scene 2
A
B
C
D
SQA Biotechnology Higher Section A 2009 Q29
4.
The gel image shown below has two lanes. The DNA is loaded onto the gel at the
origin. To separate the DNA fragments a negative charge is applied to the origin
of the gel. What conclusion could be made about the DNA fragments?
1
2
origin
A
The size of the DNA fragment in lane 1 is greater than in lane 2.
B
C
D
The size of the DNA fragment in lane 2 is greater than in lane 1.
The charge of the DNA fragment in lane 1 is positive.
The charge of the DNA fragment in lane 2 is positive.
IB Biology Higher Level Paper 1 Nov 2008 Q11
2
5.
Which features of DNA fragments are used to separate them in the process of gel
electrophoresis?
A
their charge and their size
B
their charge and base composition
C
the sequence of their bases and their charge
D
their base composition and their size
IB Biology Higher Level Paper 1 (TZ1) May 2008 Q11
6.
The result of profiling various DNA samples in a criminal investigation is shown
below.
Key:
1
2
3
4
5
1
2
3
4
blood sample of victim
blood sample of suspect X
blood sample of suspect Y
first sample from forensic
evidence
second sample from forensic
evidence
5
Which of the following could the DNA analyst conclude about the crime?
A
Only suspect X was involved.
B
Only suspect Y was involved.
C
Suspects X and Y were both involved.
D
Neither suspect X nor Y was involved.
SQA Biology Advanced Higher Section A 2008 Q12
3
7.
The biological father of four children has gone missing. A forensic scientist is
reconstructing his DNA profile to help trace him.
The DNA profile of the four children and their biological mother is shown
below.
Key:
1
2
3
4
5
1
2
3
4
mother
child P
child Q
child R
child S
5
Which of the following is likely to be the DNA profile of the missing father?
A
B
C
D
SQA Biotechnology Higher Section A 2008 Q30
8.
What is the aim of the Human Genome Project?
A
B
C
D
identify human infectious diseases
make improvements to the human genome
allow transfer of genes from other species to humans
sequence genetic information in humans
4
9.
The diagram below shows some DNA bands in a gel.
X
Y
DNA size increases
Which of the following statements is/are correct?
(1) DNA moves from left to right under an electric field.
(2) X is connected to the positive terminal of the power supply.
(3) Each DNA band contains a chromosome.
A
B
C
D
(1) only
(2) only
(3) only
(1) and (3) only
10. Which of the following statements about the process of gel electrophoresis is not
correct?
A
B
DNA samples have to be cut before loading into the wells.
DNA fragments move under an electric field because it is positively
charged.
C
D
DNA fragments are separated according to their size.
Staining is needed to see the DNA bands.
Directions: Questions 11 to 13 refer to the major steps for cloning a gene of interest
below.
(1) Introduce the plasmid into a host cell.
(2) The gene of interest increases in number.
(3) Isolate the gene of interest from a donor cell.
(4) Insert the gene into a plasmid.
11. Which of the following is the correct sequence of the steps?
A
B
C
D
(1), (2), (3) and (4)
(2), (3), (1) and (4)
(3), (4), (1) and (2)
(4), (1), (3) and (2)
5
12. Enzyme X can cut DNA at specific sites, producing small fragments. Which of
the following steps involve the use of enzyme X?
A
C
(1) and (2) only
(2) and (4) only
B
D
(1) and (3) only
(3) and (4) only
13. Enzyme Y can join DNA fragments together. Which of the following steps
involves the use of enzyme Y?
A
C
(1) only
(3) only
B
D
(2) only
(4) only
14. Which of the following is not an advantage of applying recombinant DNA
technology in agriculture and food production?
A
B
C
D
increasing the yield
increasing the popularity of the food
increasing the nutritional value of the food
reducing the cost
15. Genetic engineering
(1) involves the manipulation of genes.
(2) changes the genetic make-up of an organism.
(3) can be done by using recombinant DNA technology.
A
B
C
D
(1) and (2) only
(1) and (3) only
(2) and (3) only
(1), (2) and (3)
Directions: Questions 16 and 17 refer to the diagram below, which shows a
recombinant plasmid involved in the production of human insulin using
recombinant DNA technology.
human
insulin
gene
plasmid
16. Which of the following cells is the best source of the human insulin gene?
6
A
E. coli
B
C
D
pig pancreatic cell
human red blood cell
human pancreatic cell
17. Which cell should the recombinant plasmid be introduced into for rapid
replication?
A
B
C
D
bacterial cell
plant cell
pig pancreatic cell
human pancreatic cell
18. Which of the following are the benefits of the Human Genome Project?
(1) It helps scientists understand how genes control biological processes.
(2) It helps develop new treatment methods for diseases.
(3) It overcomes all problems created by genetic engineering.
A
C
(1) and (2) only
(2) and (3) only
B
D
(1) and (3) only
(1), (2) and (3)
19. The diagram below shows some genetically modified (GM) tomatoes.
Which of the following modifications can be made in tomatoes using
recombinant DNA technology?
(1) More nutrients can be added.
(2) The shelf life of tomatoes can be extended.
(3) The taste of tomatoes can be made sweeter.
A (1) and (2) only
B (1) and (3) only
C (2) and (3) only
D (1), (2) and (3)
20. Which of the following are the goals of the Human Genome Project?
7
(1) To sequence human DNA.
(2) To modify human genes.
(3) To map human genes.
A
C
(1) and (2) only
(2) and (3) only
B
D
(1) and (3) only
(1), (2) and (3)
8
Short questions
1.
Outline a basic technique for gene transfer.
(6 marks)
IB Biology Standard Level Paper 2 (TZ1) May 2009 Q7
2.
Outline some of the outcomes of the sequencing of the human genome.
(3 marks)
IB Biology Standard Level Paper 2 (TZ2) May 2009 Q2
3.
Genetic engineering has the potential to prevent or treat genetic disease.
If genes are to be used in this way, it is necessary to understand the biology of
suitable vectors, such as bacterial plasmids.
The diagram below shows a bacterium.
plasmid
Describe the structure of bacterial plasmids and explain why they make good
vectors.
(4 marks)
OCR GCE (A) Human Biology Jan 2009 Q7
4.
Progress in the use of genetic engineering to treat human genetic disease has
been greatly accelerated by the Human Genome Project.
a
Suggest how the Human Genome Project has contributed to the use of
genetic engineering to treat genetic diseases.
b
(2 marks)
State the ways in which the information gained from the Human Genome
Project and the development of genetic engineering could create social and
ethical issues.
(4 marks)
OCR GCE (A) Human Biology Jan 2009 Q7
9
5.
The diagram below shows a DNA profiling of a family with five children.
Segments of the DNA inherited by some members of the family are shown as
two dark bands in each column.
The DNA fragments are labelled U to Z.
son 1
son 2
son 3
son 4 daughter mother
father
maternal paternal paternal
grand- grand- grandmother father mother
U
V
W
X
Y
Z
a
State two properties of the fragmented pieces of DNA which allow them to
be separated in gel electrophoresis.
(1 mark)
b
Determine which DNA fragment son 2 inherited from his mother and which
from his father.
(1 mark)
c
Identify the child that genetically most resembles one of the grandparents.
(1 mark)
d
Apart from determining family relationships, outline one other application
for DNA profiling.
(1 mark)
IB Biology Standard Level Paper 2 Nov 2007 Q3
10
6.
The diagram below shows a bacterium with several pieces of circular DNA in
addition to the bacterial chromosome.
circular
DNA
bacterial
chromosome
a
Name the circular DNA.
(1 mark)
b
Describe the role of the circular DNA in the production of human insulin in
bacteria using recombinant DNA technology.
c
Explain why human insulin can be produced in bacteria with the circular
DNA introduced.
7.
(3 marks)
(2 marks)
DNA fingerprinting can be used to identify criminals. The diagram below shows
four DNA fingerprints. One of them is from a blood sample found at the crime
scene and the other three are from three suspects.
blood sample
found at the
crime scene
a
i
suspect suspect suspect
X
Y
Z
Name the technique that is used to separate DNA fragments.
(1 mark)
ii
Describe the principle of this technique.
(3 marks)
b
Which suspect is most likely to be the criminal?
(1 mark)
c
State one other application of DNA fingerprinting.
(1 mark)
11
8.
DNA fingerprints are used to identify the murderer in a legal case. A blood
sample collected at the crime scene, blood samples of the victim and the three
suspects are analysed using gel electrophoresis. The results are shown below.
blood sample
found at the
crime scene
victim
suspect X
suspect Y
suspect Z
a
Describe how the DNA analyst can keep a record of the results. (1 mark)
b
Explain why the DNA of the victim has to be included in the analysis.
(2 marks)
c
Which suspect is most likely to have committed the crime? Explain briefly.
(2 marks)
9.
Scientists are now using recombinant DNA technology to produce genetically
modified organisms (GMOs).
a
GMOs are widely used in agriculture for food production. State two
possible advantages of using GMOs in agriculture.
(2 marks)
b
GM bacteria can be used to produce human proteins like human growth
hormone. Describe how this can be done.
(4 marks)
c
State one other use of GMOs.
(1 mark)
12
10. Complete the following paragraph with suitable words.
(4 marks)
A genome refers to the DNA sequence on a ______ set of chromosomes in an
organism. The Human Genome Project is a research project aims at determining
the complete b ______ of human DNA, c ______ all the genes in the human
genome, developing related new technologies and addressing the d ______, legal
and social issues that may arise from the project.
11. Two major tasks in the Human Genome Project are DNA sequencing and
mapping. Distinguish between these two tasks.
(4 marks)
12. The diagram below shows the DNA fingerprints from a blood sample collected at
the crime scene and blood samples from two suspects.
blood sample suspect P
found at the
crime scene
a
suspect Q
According to the DNA fingerprints, which suspect is more likely to have
committed the crime? Explain briefly.
b
(2 marks)
State two advantages of using DNA fingerprints as evidence in legal cases.
(2 marks)
13. Read the passage below and answer the questions that follow.
Genetic engineering is the changing of the genetic make-up of an
organism by direct manipulation of genes or DNA. In the United States,
farmland for growing genetically engineered crops has increased from about 8
million acres in 1996 to more than 67 million acres in 1998.
List the advantages of growing genetically engineered crops, in terms of quality
of crops, crop yield, pest control and environmental conservation.
(4 marks)
13
14. Read the passage below and answer the questions that follow.
Bt is a bacterium in the soil that can produce a pest-killing protein. In
1996, genetically modified crops with pest resistance became available. The
gene for the pest-killing protein was cut from Bt bacterium and inserted into
the DNA of the crops. When pests eat the leaves of the Bt crops, the pests will
die within a few days.
a
Name the technology used to produce Bt crops.
(1 mark)
b
What desirable character is introduced into Bt crops?
(1 mark)
c
What kind of substance can be used to cut the gene of interest from the Bt
bacterium?
d
(1 mark)
List one benefit of Bt crops to the farmers and one benefit of Bt crops to the
environment.
(2 marks)
14
Structured questions
15. In an experiment, gel electrophoresis is used to separate DNA fragments. The
diagram below shows the pattern of bands obtained. Lane 1 is loaded with a
DNA marker containing DNA fragments of known size. Lanes 2 and 3 are loaded
with two DNA samples.
lane
1
2
3
upper
side
well
X
Y
Z
lower
side
a
What is the aim of this experiment?
(1 mark)
b
What are the functions of the agarose gel?
(2 marks)
c
What is the function of the DNA marker?
(2 marks)
d
Which side of the agarose gel, the upper side or the lower side, was
connected to the positive terminal of the power supply? Explain your
answer.
e
Explain why a fluorescent dye has to be added to the agarose gel after gel
electrophoresis.
f
(3 marks)
(1 mark)
Which of the bands, X, Y or Z, contains the shortest DNA fragments?
Explain your answer.
(2 marks)
15
16. a
The Human Genome Project was started in 1990.
This project has provided information about the inheritance of some genetic
diseases.
b
i
What is the human genome?
(1 mark)
ii
State two other aims of the Human Genome Project.
(2 marks)
Discuss the ethical and social implications of diagnosing genetic disease.
(5 marks)
OCR GCE (AS) Human Biology Jan 2009 Q4
17. The diagram below shows the DNA fingerprints of a family.
father
a
mother
daughter
Explain how the DNA fingerprints show the parent-child relationship
between the four people.
b
son
(2 marks)
By referring to the events that occur during gamete formation, explain why
the patterns of bands in the DNA fingerprints of the son and the daughter
are different.
c
(4 marks)
How would the DNA fingerprints of identical twins appear? Explain briefly.
(2 marks)
16
18. The diagram below shows how human insulin is produced by recombinant DNA
technology.
plasmid
human insulin
gene
recombinant
plasmid
bacteria
bacteria with
recombinant plasmid
human insulin
a
Explain the term recombinant DNA technology.
(1 mark)
b
What is a recombinant plasmid?
(1 mark)
c
State two enzymes that are required in the production of the recombinant
plasmid in the diagram. Give the function of each enzyme.
d
(4 marks)
Describe how to obtain pure human insulin from the bacteria with the
recombinant plasmid.
(3 marks)
e
What is the medical use of human insulin?
(1 mark)
f
State two advantages of producing human insulin using recombinant
technology over the traditional method of extracting insulin from the
pancreases of cattle.
(2 marks)
17
19. a
If the human body fails to produce a certain protein, diseases may result.
Name one such disease and give the protein involved.
b
(2 marks)
One method to control these diseases is to inject proteins that are extracted
from animal tissues. State two disadvantages of using proteins extracted
from animal tissues.
c
(2 marks)
Due to advances in biotechnology, human proteins can be produced by
bacteria using recombinant DNA technology.
i
Briefly describe the process involved.
(5 marks)
ii
State two advantages of using bacteria to produce human proteins.
(2 marks)
20. a
b
What is genetic engineering?
(2 marks)
Genetically modified organisms (GMOs) can be created using genetic
engineering. List four ways in which GMOs can be beneficial to human life.
(4 marks)
c
State two potential hazards imposed by genetic engineering.
(2 marks)
21. Read the passage below and answer the questions that follow.
Traditionally, vaccines have been prepared either by killing a specific
pathogen or by making it unable to grow. Today, vaccines are made by using
recombinant DNA technology. Gene that codes for the surface protein of the
pathogen is introduced into harmless bacteria. The modified bacteria produce
the surface protein, which will become the active ingredient of the vaccines.
The vaccines produced by this method are safer than those produced using the
traditional method.
a
Explain why vaccines produced by using recombinant DNA technology are
safer than the vaccines produced by the traditional method.
b
(3 marks)
Draw a flow chart to illustrate how the vaccine against hepatitis B can be
produced using recombinant DNA technology.
(6 marks)
18
22. Read the passage below and answer the questions that follow.
In a test done by the Consumer Council, 6 out of 10 samples of
vegetarian food products were found to contain genetically modified (GM) soy
ingredients. The ingredients come from soybeans produced by genetic
engineering to make them resistant to a non-selective herbicide. In Hong
Kong, food manufacturers are not required to declare GM ingredients in their
food products.
a
i
What are genetically modified organisms?
(1 mark)
ii
iii
What desirable character do the GM soybeans have?
(1 mark)
State two benefits offered by the character in ii to the farmers.
(2 marks)
b
How can the Consumer Council test whether the food samples contain GM
soy ingredients?
(2 marks)
c
The production of GM food is not fully supported by the public and some
people urge the government to implement a compulsory GM food labelling
system.
i
State two criticisms of producing GM food.
(2 marks)
ii
Give two benefits offered by GM food labelling.
(2 marks)
23. a
Genetic engineering can be beneficial and harmful to humans. List three
benefits and three harmful effects brought about by genetically modified
organisms (GMOs) in agriculture.
(6 marks)
b
Suggest two measures to regulate the development of genetic engineering.
(2 marks)
19
Essays
24. Discuss the ethical, legal and social issues that arise from the Human Genome
Project.
(11 marks)
25. Describe the major steps of DNA fingerprinting and discuss the applications of
DNA fingerprinting in forensic science.
(11 marks)
20
Answers
Questions No.
Key
Question No.
1.
31.
2.
32.
3.
33.
4.
34.
5.
35.
6.
36.
7.
37.
8.
38.
9.
39.
10.
40.
11.
41.
12.
42.
13.
43.
14.
44.
15.
45.
16.
46.
17.
47.
18.
48.
19.
49.
20.
50.
21.
51.
22.
52.
23.
53.
24.
54.
25.
55.
26.
56.
27.
57.
28.
58.
29.
59.
30.
60.
Key
21
1.
A plasmid is removed from bacteria.
1m
The plasmid is cut open by an enzyme.
1m
The DNA is extracted from the donor cell.
1m
DNA from the donor cell is cut using the same enzyme.
1m
The plasmid and the gene of interest are mixed and joined using another enzyme to
form a recombinant plasmid.
1m
The recombinant plasmid is inserted into a host cell.
1m
2.
The location of human genes / position of human genes on chromosomes will be known. /
The number of genes / interaction of genes will be known. / We can understand more
about the mechanism of mutations. /
We will know more about the evolutionary relationships between humans and other
animals. /
Some proteins may be discovered. / We can understand more about the functions of
proteins. / Some genetic diseases may be detected. /
The sequence may lead to the development of medical treatments / enhance research
techniques. /
We may know more about the base sequence of the genes. / Sequencing may allow the
study of variations between individuals within the genome. (any 3)
1m x 3
Plasmids are circular molecules / rings of DNA.
1m
3.
They can be cut by enzymes. /
The gene of interest can be easily incorporated in the plasmids. /
They can be taken up by bacteria. /
They can be genetically engineered. /
They can clone themselves. (any 3)
1m x 3
22
4.
a
The Human Genome Project has located the loci of some genes. /
The Human Genome Project has identified the differences in genotypes of
individuals with a genetic disease. /
The Human Genome Project has identified some genes coding for proteins which
may be malfunctioning. (any 2)
b
1m x 2
It is difficult to decide who owns the information. /
It is difficult to decide who has access to the information. /
Discrimination against people when obtaining insurance / applying for mortgages
may result. /
Some individuals may not want to know whether they have genetic diseases. /
Changing somatic cells during genetic engineering does not prevent the damaged
alleles from being passed on to the next generation. /
Genetic engineering may create genetic underclass. (any 4)
1m x 4
a
Charge and size
1m
b
V is inherited from his mother while Y is from his father.
1m
c
Son 1
1m
d
DNA profiling is used in criminal investigations to confirm suspects / used in
5.
tracking individuals in populations. (or other reasonable answers)
1m
a
Plasmid
1m
b
The plasmid acts as a vector.
1m
The plasmid carries the human insulin gene
1m
and transfers it into a bacterium.
1m
The human insulin gene in the plasmid is expressed.
1m
6.
c
Human insulin is produced by the process of protein synthesis using the
machinery of the bacterium.
1m
23
7.
a
i
Gel electrophoresis
1m
ii
DNA is negatively charged due to the phosphate groups present.
1m
DNA fragments move towards the positive terminal under an electric field.
1m
The molecular space in the gel allows shorter DNA fragments to move faster
than the longer ones.
1m
b
Suspect Y
1m
c
It can be used in victim identification / parentage test.
1m
a
The pattern of bands can be copied to a photographic film.
1m
b
It is to compare with the blood sample found at the crime scene.
1m
8.
The bands that appear in the DNA fingerprint from the blood sample found at the
crime scene but do not appear in the DNA fingerprint of the victim are likely to be
c
from the murderer.
1m
Suspect Y
1m
The bands match with those from the blood sample found at the crime scene.
1m
9.
a
The GMOs may grow faster. /
The GMOs may grow in undesirable environments. / may be more tolerant to
drought / cold / salinity / resistant to pests / diseases / herbicides. /
The food from GMOs may have a longer shelf life. /
The food from GMOs may contain more nutrients. /
It may be cheaper to grow GMOs. (any 2 or other reasonable answers)
b
1m x 2
DNA fragments containing the human growth hormone gene are obtained. 1m
The DNA fragments are cut with a specific enzyme.
1m
The DNA fragments are inserted into plasmids and the recombinant plasmids are
c
introduced into the bacteria.
1m
The bacteria express the gene and produce human growth hormone.
1m
GMOs can be used to produce human insulin / vaccines / chemical products / break
down oil spills / extract metals from ores.
1m
24
10.
a
one
1m
b
base sequence
1m
c
locating / mapping
1m
d
ethical
1m
11.
DNA sequencing is to determine the exact order of all base pairs in the DNA molecules of all
chromosomes.
2m
Mapping is to determine the location of all the genes in the human genome on the
chromosomes.
2m
a
1m
12.
Suspect Q
because the bands in suspect Q’s DNA fingerprint match with the bands in the DNA
fingerprint from the blood sample found at the crime scene.
b
1m
DNA fingerprint is unique to each individual. / DNA fingerprint of an individual does not
change over time / is not affected by the environment. /
DNA fingerprinting is an accurate method for identifying an individual. /
Only a small amount of DNA is needed. (any 2)
1m x 2
13.
The crops may have more nutrients. / The flavour and texture of the crops can be
improved. / The crops may have a longer shelf life.
1m
The crop yield can be increased as the crops can grow faster.
1m
Resistance of the crops to pests / herbicides can be increased.
1m
The use of fertilizers and pesticides can be reduced, thus causing less pollution. 1m
(or other reasonable answers)
25
14.
a
Recombinant DNA technology
1m
b
Pest resistance
1m
c
Enzyme
1m
d
The farmers can use less pesticide, thus the cost is lowered. / Fewer crops are
eaten by the pests, thus more crops are available for sale.
1m
As herbicide causes pollution when it is washed into rivers, using less herbicide
means causing less pollution.
1m
15.
a
To find out the size of the DNA fragments in the two DNA samples.
1m
b
It is used to contain the DNA
1m
and to provide a medium in which DNA fragments can be separated.
1m
It can be used to determine the size of the DNA fragments in the samples
1m
c
by comparing the positions of the bands of the samples and the DNA marker.
1m
d
The lower side was connected to the positive terminal of the power supply. 1m
The DNA fragments are negatively charged . They move towards the positive
terminal under an electric field.
1m
From the diagram, the DNA fragments moved from the upper side to the lower side,
indicating that the lower side was connected to the positive terminal.
1m
e
It allows the DNA fragments to be seen under ultraviolet light.
1m
f
Z
Z is furthest away from the well,
1m
indicating that its DNA fragments moved the fastest under the electric field, and
thus the DNA fragments are the shortest.
1m
16.
a
i
Human genome is the complete set of inherited information / genes in a
human.
ii
1m
To identify all of the human genes. /
To determine the base sequence of human DNA. /
To store the information. /
To develop related new technologies. /
To address the ethical, legal and social issues. (any 2)
1m x 2
26
b
The disease may be incurable, causing anxiety to the patient.
1m
Diagnostic test on the foetus / embryo may cause miscarriage / may raise religious
issues of termination of pregnancy.
1m
The diagnosis of genetic disease may lead to discrimination by employers /
insurance companies.
1m
The diagnosis of genetic disease may affect the public perception of an individual.
1m
Some may think that the money used should be spent on other areas like
developing life saving techniques.
1m
(or other reasonable answers)
17.
a
b
Half the bands in the DNA fingerprints of the son and the daughter come from the
father,
1m
and the other half come from the mother.
1m
The patterns of bands are different because genetic variations exist between
offspring.
1m
During meiotic cell division, the homologous chromosomes line up and separate
independently.
1m
The gametes formed will have different genetic combination.
1m
The gametes fuse randomly during fertilization, therefore each zygote produced
c
has different genetic combination from their mother and father.
1m
The DNA fingerprints of identical twins are the same.
1m
This is because their genetic make-up is identical.
1m
18.
a
Recombinant DNA technology refers to the techniques that a fragment of DNA from a
donor cell or organism is isolated and inserted into the DNA of another cell or
organism.
1m
b
Recombinant plasmid is a plasmid into which a gene of interest is inserted. 1m
c
An enzyme that works like a pair of scissors is needed.
1m
It is used to produce sticky ends in the human insulin gene and the plasmid. 1m
An enzyme that works like glue is needed.
1m
It is used to join the human insulin gene and the plasmid together.
1m
27
d
The bacteria containing recombinant plasmid are allowed to grow and reproduce.
1m
Human insulin gene in the recombinant plasmid is expressed in the bacteria. Human
insulin is produced.
1m
Human insulin produced is isolated from the bacteria and purified before use.
1m
e
It is injected into the body of the patients with type 1 diabetes to control the blood
glucose level.
f
1m
Human insulin will not cause immune response / allergy / has fewer side effects. /
The production cost is lower. /
It can be produced in larger quantity in a shorter time. /
It is safer as the insulin extracted from cattle may be contaminated and may contain
impurities.
(any 2 or other reasonable answers)
1m x 2
Disease: diabetes / dwarfism
1m
Protein: insulin / growth hormone
1m
19.
a
(or other reasonable answers)
b
Many animal tissues are needed. /
The animal proteins are slightly different from the human proteins, which may
cause immune response / allergy. /
The extracted animal proteins may be contaminated and may contain impurities. /
c
The cost is high. (any 2 or other reasonable answers)
1m x 2
i
The gene that codes for the protein is isolated from a human cell.
1m
It is then inserted into a vector / plasmid.
1m
The vector / plasmid is then introduced into a bacterium.
1m
The gene is expressed to produce the protein.
1m
The protein is then isolated and purified for use.
1m
ii
Human proteins will not cause immune response / allergy / has fewer side
effects. /
The production cost is lower. /
It can be produced in larger quantity in a shorter time. /
28
The product produced contains fewer impurities.
(any 2 or other reasonable answers)
1m x 2
20.
a
Genetic engineering is the changing of the genetic make-up of an organism 1m
by direct manipulation of genes or DNA.
b
1m
GMOs can be used to produce pharmaceutical products. /
GMOs can be used to improve the productivity and quality of farm animals and
crops. /
GMOs can be used to produce GM food. /
GMOs can be used to produce chemical products. /
GMOs can be used to break down oil spills. /
GMOs can be used to extract metals from ores more efficiently. (any 4)
c
1m x 4
Genetic engineering may cause unknown harmful effects to human health. /
Genetic engineering may disturb ecological balance in a habitat. /
Genetic engineering may pose financial threat to the farmers in the poor countries. /
Genetic engineering may give rise to ethical problems such as violation to the value
of organisms in nature. (any 2)
1m x 2
21.
a
If some of the pathogens in the traditional vaccines are not killed or weakened,
people who have been vaccinated may be infected.
1m
Vaccines produced by recombinant DNA technology contain only the surface
proteins of the pathogens instead of the whole pathogens.
1m
The surface protein will not cause infection.
1m
29
b
Obtain DNA containing the gene for
the surface protein from hepatitis B
virus
Extract the plasmid from bacteria
Cut the DNA with an enzyme
Cut open the plasmid with an
enzyme
Join the DNA fragment and the
plasmid together with an enzyme
to form a recombinant plasmid
Introduce the recombinant plasmid
into bacteria
Bacteria express the gene to
produce surface protein
Isolate and purify the surface
protein for use in vaccine
6m
22.
a
i
Genetically modified organisms are organisms that the genetic make-up is
changed in a way that does not occur naturally by mating.
1m
ii
Resistance to a non-selective herbicide
1m
iii
This character allows the farmers to control weeds by applying the
non-selective herbicide without killing the soybeans.
1m
The production cost is lowered. / The quantity of soybean can be increased.
1m
b
GM soy ingredients come from GM soybeans that contain inserted genes.
1m
The Consumer Council can test the food samples for the presence of the inserted
genes.
c
i
1m
GM food may cause unknown health problems to humans. /
GM crops may modify the DNA of similar plant species by cross-pollination. /
The planting of GM crops in industrialized countries may reduce the
dependence of food supply from the poor countries and hence pose a financial
30
threat to the farmers in the poor countries. /
The modification of DNA violates the value of organisms in nature. /
GM crops may out compete other plants in nature, upsetting the balance of the
ecosystem. (any 2)
ii
1m x 2
Labelling offers consumers the right to know what is in their food. /
Labelling allows easy identification, tracing and verification if problems occur. /
Average quality of food will increase because labelling makes food
manufacturers responsible for their products. (any 2)
1m x 2
23.
a
Benefits:
Crop yields can be increased / cost can be lowered by growing GM crops. /
Food produced by GM crops may have higher nutritional value. /
GM crops may have increased resistance to herbicides / pests / diseases / tolerance
to cold / drought / salinity, thus crops can grow in areas of different environmental
conditions. /
Wastage of food can be reduced as the GM foods may have a longer shelf life.
(any 3 or other reasonable answers)
1m x 3
Harmful effects:
GM crops may cause unknown health problems to humans. /
GM crops may modify the DNA of similar plant species by cross-pollination. /
The planting of GM crops in industrialized countries may reduce the dependence of
food supply from the poor countries and hence pose a financial threat to the farmers
in poor countries. /
GM crops may out compete other plants in nature, upsetting the balance of the
ecosystem. (any 3 or any reasonable answers)
b
1m x 3
Ban the cloning of humans. /
Monitor the experiments involving GMOs to avoid the gene in GMOs from spreading
into the wild. /
Legislation to define what is ethical and lawful.
(any 2 or any reasonable answers)
1m x 2
31
24.
Ethical issues:
Would the diagnosis of an incurable disease cause anxiety to the patients?
2m
Legal issues:
Who can gain access to personal genetic information, the insurance company, the
employers, the government departments, the schools or the clinics?
2m
Who is the owner of personal genetic information?
2m
Social issues:
How does the personal genetic information affect the public perception of an individual?
2m
(or other reasonable answers)
Effective communication
3m
25.
DNA fingerprinting refers to the techniques involved in the use of DNA analyses to
identify individuals.
1m
It makes use of the 0.1% of the base sequence in DNA that is unique to each individual.
1m
To generate the DNA fingerprint of an individual, DNA is first extracted from the cells of
the individual.
1m
DNA fragments containing the highly variable regions are obtained through proper
processes.
1m
The DNA fragments are separated by gel electrophoresis according to their size. 1m
A specific pattern of bands is shown on the gel after gel electrophoresis. This pattern is
unique to each individual.
1m
By comparing the pattern of bands of suspects with that from the blood sample collected
at the crime scene, the criminal may be identified.
1m
It is an accurate method and therefore it can be used to provide evidence to the court in
legal cases.
1m
Effective communication
3m
32