lq - 24 genetic engineering

Certificate Biology New Mastering Basic Concepts Chapter 24Question Bank V2.0 Structured Questions

Ch 24 Genetic engineering

[241001]

[E] a Diseases might be caused by the deficiency of human proteins. Name one

human protein and its deficiency disease. (2 marks)

b Name three disadvantages of using proteins extracted from animal tissues.

(3 marks)

c Human proteins can be produced by bacteria. Briefly describe the process.

(4 marks)

d State one advantage and one disadvantage of using bacteria to produce

human proteins. (2 marks)

e State one advantage of human proteins produced in the milk of transgenic

animals, e.g. sheep, when compared to that produced in bacteria. (1 mark)

-- ans --

a Insulin, diabetes 1m+1m

OR any other reasonable answers

b Many tissues are needed. 1m

The animal proteins are slightly different from the human proteins. 1m

The animal proteins may cause side effects. 1m

c The gene responsible for the production of the protein is removed from the cells in

humans. 1m

It is then inserted into the bacteria. 1m

When the bacteria reproduce, many copies of the desired gene are produced. 1m

The protein is then extracted and purified for sale and use. 1m

d Advantage:

Large amount of proteins can be produced in a short time. /

Oxford University Press 2005 / 18


The proteins are human proteins in nature. 1m

Disadvantage:

It may lead to unexpected 'super bacteria' which may harm other organisms. /

The proteins may have unexpected side effects on human health. 1m

e The threat of 'super bacteria' is avoided. /

The side effects will be much more reduced as the proteins are produced by

mammals. /

The cost is lowered. 1m

-- ans end --



[241002]

Read the following article and answer the questions below.

The process of producing living organisms having desired traits by using

traditional artificial breeding is very time-consuming. In 1996, scientists

successfully created Dolly, the first animal cloned from a mammary gland

cell of a six-year old sheep. Her birth started the current fascination for

cloning all other things. It also turned down the thought of most biologists

that the cells in our bodies were fixed in their roles.

a Give two reasons why Dolly was created by scientists in 1996. (2 marks)

b Genetic engineering is applied in different areas. Name four areas it can be

beneficial to human life. Give an example to each area. (8 marks)

c Humans are worried about the harmful effects caused by genetic

engineering. State three potential hazards imposed by it. (3 marks)

-- ans --

a To produce living organisms possessing desired traits in a short time. /

To clone organisms from body cells. /

To challenge the impossibilities. (Any 2, 1 m each)

b Increase crop yields, e.g. a large amount of GM tomatoes can be produced in a

short time. /

Produce food with enriched nutritive value, e.g. GM rice containing more vitamin A

and iron. /

Increase resistance of crops to pests and increase their tolerance to cold, drought

or salinity, e.g. GM corn can produce a toxic protein when attacked by pests, thus

reducing the use of pesticides. /

Eliminate the allergy-causing properties of food, e.g. the proteins in the milk from

GM cows are modified so that they may not cause allergies to humans. /

Reduce wastage and cost of food, e.g. GM tomatoes can last longer and be sold in

the market for a longer time. /



Produce drugs, e.g. human insulin, growth hormones, haemoglobin, vaccines and

antibodies. (Any 4, 1m+1m each)

c A threat to cause unknown harmful effects to human health. /

A threat to disturb ecological balance in a habitat. /

A threat to pose financial threat to the farmers in the third world. /

Ethical problems such as production of GM food violates the value of organisms in

nature. /

Possible production of 'super organisms'. (Any 3, 1m each)

-- ans end --



[241003]

a i Genetic engineering is both beneficial and harmful to our living. Give

three points on each side to explain it. (6 marks)

ii Suggest two measures to regulate the development of genetic

engineering. (2 marks)

[E] b Genetic engineering can be applied in producing drugs. Name one drug and

describe its production by means of genetic engineering. (5 marks)

-- ans --

a i Benefits:

Increase crop yields /

Produce food of enriched nutritive value /

Increase resistance of crops to pests or increase their tolerance to cold,

drought or salinity /

Eliminate the allergy-causing properties of food /

Reduce the wastage and cost of food /

Produce drugs (Any 3, 1m each)

Harmful effects:

A threat to cause unknown harmful effects to human health. /

A threat to disturb ecological balance in a habitat. /

A threat to pose financial threat to the farmers in the third world. /

Ethical problems such as production of GM food violates the value of

organisms in nature. /

Possible production of 'super organisms'. (Any 3, 1m each)

ii Do not clone humans. /

Preventive measures to avoid the spread of 'super organisms' outside the

laboratories. /



Legislation to define what is ethical and lawful.

OR any reasonable answers (Any 2, 1m each)

b Insulin. 1m

The gene responsible for the production of insulin is removed from the cells in

humans. 1m

It is then inserted into the bacteria. 1m

When the bacteria reproduce, many copies of the insulin gene are produced. 1m

The insulin is then extracted and purified for sale and use. 1m

-- ans end --



[241004]

Read the following article and answer the questions below.

Traditionally, vaccines have been prepared either by killing a specific

pathogenic micro-organism or by making it unable to grow. Today there is

a new and much safer method of making vaccines. Using genetic

engineering techniques, the genes that encode the pathogen's surface

proteins can be inserted into the DNA of harmless bacteria or viruses. The

modified micro-organisms become an effective and safe vaccine to

stimulate the body to produce the antibodies. As a result, the body is

protected from infection.

a Why is it unsafe to use the traditional vaccines? (2 marks)

b Draw an annotated diagram to illustrate the method of making severe acute

respiratory syndrome (SARS) vaccines by using genetic engineering

techniques. (6 marks)

-- ans --

a If the pathogen fails to be killed or weakened, it will transmit the disease to the

person seeking protection. 2m

b

Diagram 3m

Annotations 3m

-- ans end --



[241005]

Read the following article extracted from the webpage of the department of

agriculture in the US and answer the questions below.

Genetic engineering is a technique used to alter or move genetic material

of living cells. U.S. acreage using genetically engineered crops has

increased from about 8 million acres in 1996 to more than 67 million acres

in 1998, in major states where data have been collected.

List the advantages of using genetically engineered crops by US farmers, in

terms of quality of crops, crop yield, pest control and environmental

conservation.

(5 marks)

-- ans --

Advantages:

Increase crop yield in a short time.

Produce crops with enriched nutritive value.

Increase resistance of crops to pests.

Increase tolerance of crops to cold, drought or salinity.

Reduce the use of fertilizers and pesticides.

Reduce the wastage and cost of food.

Eliminate the allergy-causing properties of food.

Improve flavour and texture of food. (Any 5, 1m each)

-- ans end --



[241101]

Answer the questions below with reference to the following news about

genetically modified (GM) food.

Vegetarian foods contain GM ingredients

In a test done by the Consumer Council, 6 out of 10 samples of

vegetarian food products were found to contain genetically modified

soy ingredients. The ingredients come from soybeans produced by

genetic engineering to render 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 the genetically modified organisms mentioned in the

news?

(1 mark)

ii What new desirable character do the organisms in i have? (1 mark)

iii State one benefit offered by the character in ii. (1 mark)

b How did the Consumer Council know some of the food samples contained

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)

-- ans --

a i Soybeans 1m

ii Resistance to a non-selective herbicide 1m



iii To control weeds by applying the non-selective herbicide without killing the

soybeans. 1m

b GM soy ingredients come from GM soybeans that contained inserted genes. 1m

The presence of the inserted genes in the food samples indicated that the food

samples contained GM soy ingredients. 1m

c i GM food may cause unknown health problem to humans. /

GM food may lead to the transfer of antibiotic resistance genes to

pathogens. /

GM crops may modify the DNA of similar plant species due to cross-

pollination. /

The planting of GM crops in industrialized countries reduces the

dependence of food supply from the third world countries and hence

poses a financial threat to the third world farmers. /

The modification of crop 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) 1m x 2

ii Offering consumers the right to know what is in their food, especially

concerning products for which health and environmental concerns have

been raised. /

Labelling allows problems to be easily identified, traced and verified,

should they occur.

More informed choices on food and health will be available, leading to an

increase in consumer confidence in product quality. /

Average quality of food will increase because labelling makes food

manufacturers responsible for their products.

(any 2) 1m x 2

-- ans end --



[241102]

Answer the questions below with reference to the following passage about Bt

crops.

Bt is a soil bacterium that can produce a pest-killing protein. In 1996,

genetically modified Bt crops with pest resistance became available. The

gene for the pest-killing protein is cut out from Bt and inserted into the DNA

of crops. When pests eat the leaves of Bt crops, the pests will die within a

few days. Although the gene from Bt has proven to be quite effective in the

short term for protecting against crop pest damage, there are concerns that

the widespread planting of Bt crops will eventually speed up the evolution of

Bt-resistant pests.

a What desirable character is introduced into Bt crops? (1 mark)

b What kind of substances can be used to cut out the target gene? (1 mark)

[E] c Based on the theory of natural selection to explain how the widespread

planting of Bt crops will speed up the development of Bt-resistant pests

from a population of non-resistant pests. (4 marks)

d Apart from the concern in c, give another two criticisms of producing Bt

crops. (2 marks)

e It is suggested to plant Bt crops in a field adjacent to a non-Bt crop field.

In this way, the Bt-resistant pests present in the Bt crop field are

encouraged to visit the non-Bt crop field where there are more non-

resistant pests (see diagram below). What is the purpose of this strategy? (2

marks)



-- ans --

a Pest resistance 1m

b By using enzymes. 1m

c Mutation in non-resistant pests may produce pests that are Bt-resistant. 1m

When there is no Bt crop, Bt-resistance is not important for the survival of pests.

1m

Under the widespread planting of Bt crops, the Bt-resistant pests become more

likely to survive and reproduce. 1m

Therefore they are more likely to pass on their Bt-resistance genes to their

offspring. 1m

d The Bt crops may cause unknown health problem to humans / non-target pests. /

The Bt crops may modify the DNA of similar plant species by cross-pollination. /

The planting of Bt crops in industrialized countries reduces the dependence of

food supply from the third world countries and hence poses a financial threat to

the third world farmers. /

The modification of DNA of crops violates the value of organisms in nature. /

The Bt crops may out compete other plants in nature, upsetting the balance of

the ecosystem.

(any 2) 1m x 2



e To encourage the mating of Bt-resistant pests with non-resistant pests, instead of

mating with Bt-resistant pests. 1m

This is to slow down the development of Bt resistance in the pest population. 1m

-- ans end --



[241103]

[E] The diagram below shows the production of genetically modified sheep for the

making of human proteins that have medicinal value. The DNA signal directs

the expression of the gene for protein drug in the mammary glands of the sheep

only.

a Which human protein was first produced commercially using genetic

engineering? (1 mark)

b Why are the gene for protein drug and the DNA signal injected into the

fertilized egg instead of a cell in the embryo? (2 marks)

c From which part of the genetically modified sheep can the protein drug be

collected? (1 mark)

d Give two advantages of using mammals to produce human proteins over

the use of bacteria. (4 marks)

e Give two public concerns over the use of animals to produce human

proteins. (4 marks)



-- ans --

a Insulin 1m

b To ensure every cell of the genetically modified sheep contains the gene for

protein drug and the DNA signal. 2m

c Milk of the sheep 1m

d Mammalian cells but not bacteria can provide the biological modifications

required by some human proteins. /

Mammals do not produce bacterial toxins. /

Mammals are easier to maintain than bacteria. /

The purification of the human proteins in the milk is easier than in bacterial

culture.

(any 2) 2m x 2

e Accidental release of the genetically modified animals into the natural

environment may cause genetic pollution. /

Accidental release of the genetically modified animals into the natural

environment may upset the balance of the ecosystem. /

The modification of the genes in the genetically modified animals may cause

health problems to them. /

The problem of disposal of malformed animals produced in the genetic

engineering process. /

The creation of new species that contain genes from both the human and the

animals. /

The new definition of the relationship between humans and animals.

(any 2) 2m x 2

-- ans end --



[241104]

[E] Cystic fibrosis is a genetic disorder caused by a defective gene. The gene lacks

the codes for an amino acid in an important protein, leading to an excessive

production of thick mucus in the lungs. The diagram below shows an attempt in

treating cystic fibrosis by gene therapy.

a Describe how copies of normal human genes can be made in bacteria.

(5 marks)

b What is the vector used in transferring the normal gene to human cells?

(1 mark)

c Give one drawback of this treatment for cystic fibrosis. (2 marks)

d Will the normal gene from the recovered patient pass to his/her offspring?

Explain your answer. (3 marks)



-- ans --

a Cut out the normal gene from a human cell. 1m

Insert the normal gene into a bacterial DNA loop (vector). 1m

Introduce the vector into a bacterium. 1m

Put the bacterium in culture. 1m

Copies of the normal gene produced as the bacterium multiplies. 1m

b Harmless virus 1m

c It takes a long time to replace all the defective lung cells with healthy cells. /

It may cause unknown health problems in the patient. (any 1) 2m

d No. 1m

The normal genes are only present in the lung cells. 1m

The gametes that pass the genes to the offspring still contain the defective

genes. 1m

-- ans end --


lq - 24 genetic engineering

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