Ce Biology 2002 Paper1(E)

2002-CE
HONG KONG EXAMINATIONS AUTHORITY
BIO
HONG KONG CERTIFICATE OF EDUCATION EXAMINATION 2002
PAPER 1

BIOLOGY PAPER 1

8.30 am – 10.00 am (1½ hours)
This paper must be answered in English

1. Attempt THREE questions only.

2. Each question consists of three parts.

3. All questions carry equal marks.

4. In each question, 2 additional marks will be awarded for effective
communication.

5. The diagrams in this paper are NOT necessarily drawn to scale.

香港考試局保留版權
Hong Kong Examinations Authority
All Rights Reserved 2002

2002-CE-BIO 1–1

1. (a) Some plants can be propagated vegetatively using tissue culture. In this
method, the culture medium is sterilized before use and it provides essential
materials for plant growth. The diagram below shows an outline of an
investigation involving tissue culture. The whole process is conducted in
the presence of light.

−1−
2002-CE-BIO 1–2
保留版權 All Rights Reserved 2002

(i) Sugar is one of the essential components of the culture medium.
Explain why sugar must be added. (3 marks)

(ii) Compare the genetic make-up of the daughter plants with that of the
parent plant. Give a reason for your answer. (2 marks)

(iii) After several weeks, plant B showed signs of yellowing while plant A
remained green. Based on the information provided, suggest an
explanation for the yellowing of plant B. (3 marks)

(iv) Give two advantages of this method of plant propagation over the
propagation using seeds. (2 marks)

−2−
2002-CE-BIO 1–3 Go on to the next page

1. (b) The diagram below shows the human skeleton and two muscles of the right
arm, M and N :

−3−
2002-CE-BIO 1–4

(i) Deficiency of vitamin D in childhood will lead to deformity of bones.

(1) Using the letters in the diagram, indicate which part of the
skeleton is most easily deformed. Explain your choice.
(3 marks)

(2) Apart from diet, suggest another way by which the body gets
vitamin D. (1 mark)

(ii) Why are muscles M and N described as an antagonistic (opposing)
pair ? (1 mark)

(iii) Draw a diagram to show the lever system involved in lifting the right
forearm. Indicate the positions of the load, the effort and the fulcrum
in your diagram.
In lifting the right forearm, what will form the load, the effort and the
fulcrum respectively ?
(5 marks)

−4−

1. (c) In a study, a healthy person and a person with diabetes mellitus fasted for
12 hours. They then stayed at rest in the same room and drank equal
volumes of glucose solutions of the same concentration. Their blood
glucose levels were measured immediately afterwards and at 30-minute
intervals for three hours. The results are shown in the graph below :

(i) What is the increase in the blood glucose level after 1 hour in
(1) the healthy person, (2) the diabetic person ? (2 marks)
(ii) Explain why the healthy person had a smaller increase in blood
glucose level in the first hour when compared with the diabetic person.
(4 marks)
(iii) During the study, a larger volume of urine was produced by the
diabetic person than the healthy person. Suggest an explanation for
this. (4 marks)

−5−
2002-CE-BIO 1–6

2. (a) The following photograph shows a female condom while the diagram on the
right shows the human female reproductive system :

(i) The female condom is placed in A during sexual intercourse. How
does the female condom contribute to contraception ? (2 marks)

(ii) Give an example of an infectious disease that can be prevented by
wearing the condom. (1 mark)

(iii) Another contraceptive method is to tie and cut both the oviducts. State
whether or not menstruation will still occur in a young woman who
has received this operation. Explain your answer with reference to the
physiological processes involved. (4 marks)

(iv) The following is a simplified diagram of a cell which is undergoing
cell division to form an ovum.
(Only two pairs of homologous chromosomes are shown in the
diagram.)

Based on the above diagram, make a drawing of the ovum formed
showing the chromosomes contained inside. (3 marks)

−6−

2. (b) The photomicrographs below show part of the transverse section of the leaf
blade of a terrestrial dicotyledonous plant and that of a moss :

T.S. of the leaf blade of the dicotyledonous plant
(magnification x100)

−7−
2002-CE-BIO 1–8

(i) (1) Name structure A. (1 mark)

(2) Explain one way in which A contributes to the function of cell B
under bright sunlight. (2 marks)

(ii) The moss above is restricted to damp and shady environments and it is
often covered with a thin film of water.

(1) With reference to the leaf structures shown in the two
photomicrographs, suggest two reasons why the moss cannot
grow well in dry environments. (4 marks)

(2) Describe how the moss leaf obtains oxygen from the atmosphere
at night. (3 marks)

−8−

2. (c) The following table shows the number of outbreaks of food poisoning due to
different causative agents in Hong Kong in 2000 :

Causative agent
Period
Bacteria Agricultural chemicals Biotoxins
January – March 80 2 11
April – June 97 7 11
July – September 189 10 17
October – December 93 37 6
Total 459 56 45

(i) Which period had the greatest number of food poisoning outbreaks
due to bacteria ? Suggest why the number of outbreaks was the
greatest in this period. (3 marks)

(ii) In some cases of bacterial food poisoning, the patient discharges a
large amount of watery faeces. Explain why this condition may be
fatal. (1 mark)

(iii) Another kind of food poisoning is caused by the consumption of
shellfish (e.g. oysters, clams) which contain a high level of a harmful
substance. This substance is actually produced in very small
quantities by certain marine microscopic algae.
(1) With reference to the table above, into which type of causative
agent would you classify this harmful substance ? (1 mark)
(2) Explain why shellfish contain such a high level of this harmful
substance. (3 marks)

(iv) The following is taken from a pamphlet on the guidelines for lunch
box suppliers to Hong Kong schools :

Advice for School Lunch Box Suppliers
1. Cook food thoroughly.
2. Keep hot foods at 63oC or higher and cold foods at 4oC or below.
3. Never leave lunch boxes at room temperature for longer than 2 hours.

Explain why points 1 and 3 are crucial in ensuring that food in the
lunch boxes is safe to eat. (2 marks)
−9−
2002-CE-BIO 1–10

3. (a) The diagram below shows a set-up used to study the water balance of a
small plant. The whole set-up was put in a well-ventilated and well-
illuminated room for 8 hours.

The initial and final readings in the measuring cylinder and the balance are
tabulated below :

Initial reading Final reading Change in reading
Water level in the
measuring cylinder 45.0 43.5 x
(cm3)
Reading of the
117.5 116.3 y
balance (g)

(i) (1) Find values x and y. (1 mark)

(2) With reference to the water balance of the plant, what do x and y
represent respectively ? (2 marks)

(3) Compare values x and y. Explain the significance of their
difference to the healthy growth of the plant. (3 marks)
(Given : 1 cm3 of water weighs 1 g)

(ii) Predict, with reasons, the change in value x if the study is repeated
with the leaves of the plant smeared with vaseline on both surfaces.
(4 marks)

−10−

3. (b) In an ecosystem, there are various types of bats. One type of bats, A, is
shown in photograph 1 below. When a sample of its faeces was examined,
pieces of legs and wings of a certain group of animals were found as shown
in photograph 2.

1
Photograph 1 (magnification x )
5

Photograph 2 (magnification x4)
−11−
2002-CE-BIO 1–12

(i) (1) To which group of vertebrates do bats belong ? (1 mark)

(2) Referring to photograph 1, state one external feature of bat A
through which it is classified into the group you stated in (1).
(1 mark)

(ii) With reference to photograph 2, suggest the group of animals that
bat A feeds on. (1 mark)

(iii) The faeces of another type of bats, B, are found to contain some seeds.
Suggest an explanation for the presence of intact seeds in the faeces of
bat B. (2 marks)

(iv) A third type of bats, C, feeds on the blood of large animals. Assuming
that bats B and C have the same amount of daily food intake, compare
the daily amount of faeces they produce. Explain your answer.
(2 marks)

(v) Having different types of bats is advantageous to the survival of bats
in an ecosystem. Suggest an explanation for this using the information
about bats A, B and C given above. (2 marks)

−12−

3. (c) An inherited abnormality in humans is the occurrence of unusually short
fingers. The photographs below show a hand with normal fingers and a
hand with this abnormality :

The length of fingers is controlled by a pair of alleles. The allele for short
fingers probably arose from a mutation of the allele for normal fingers. The
following pedigree shows the inheritance of this abnormality in a family :

2
1

5 6
3 4

Key : male with normal fingers female with normal fingers

male with short fingers female with short fingers

−13−
2002-CE-BIO 1–14

(i) (1) What is meant by mutation ? (1 mark)

(2) Explain how a mutation in a person may lead to a change in the
metabolic activities of his cells. (2 marks)

(ii) Deduce which character, normal fingers or short fingers, is dominant.
Explain your deduction. (5 marks)
(Marks will not be awarded for genetic diagrams.)

(iii) Individual 6 is going to marry a female homozygous for normal
fingers. Draw a genetic diagram to show the result of the cross.
(Use F to stand for the dominant allele and f for the recessive allele.)
(3 marks)

−14−

4. (a) Diagram 1 below shows the structure of the human ear and its connection to
the brain. Electron micrographs X and Y show the surface view of the
sensory hair cells at the same site in the ears of two persons as observed
under the same magnification :

Diagram 1

−15−
2002-CE-BIO 1–16

(i) What will be the change in the loudness of the sound heard if
structure A of a person is lost in an accident ? Give a reason for your
answer. (2 marks)

(ii) Using the letters in diagram 1, list all parts of the ear that are filled
with liquid. (2 marks)

(iii) Electron micrograph X shows the sensory hair cells taken from part E
of a normal ear.

(1) Name part E. (1 mark)

(2) Explain the role of the sensory hair cells there. (2 marks)

(iv) Electron micrograph Y shows the sensory hair cells of a person who
has been working at noisy construction sites for a long period of time.
Suggest why his sensory hair cells are different from those shown in
electron micrograph X. (2 marks)

(v) If the ear is normal but structure D is damaged completely at point P,
how will hearing be affected ? Explain your answer. (3 marks)

−16−

4. (b) The graph below shows the changes in blood pressure and velocity of blood
flow as the blood travels from the heart to the leg and returns to the heart :

(i) Compare the blood pressure in the artery with that in the vein.
Suggest two reasons for the difference. (3 marks)

(ii) Explain the importance of the low velocity of blood flow in the
capillary. (2 marks)

(iii) In the vein of the leg, the blood pressure is very low while the velocity
of blood flow is quite high. Describe how such a high velocity of
blood flow in the vein is maintained. (2 marks)

(iv) Using the same x-axis given above, sketch a graph to show the change
in the oxygen content of the blood as it passes through the blood
vessels. (3 marks)

−17−
2002-CE-BIO 1–18

4. (c) A kind of Chinese dessert is made by mixing milk with ginger juice so that
the milk becomes coagulated. The coagulation of milk is due to the
conversion of a soluble milk protein into an insoluble form. To find out the
conditions for milk coagulation, a person mixed milk at different
temperatures with some fresh ginger juice. The mixtures were observed for
15 minutes to see if coagulation would occur. The results are shown in the
table below :

Temperature of milk (oC) Result
20 No sign of coagulation after 15 minutes
40 Fully coagulated in 14 minutes
60 Fully coagulated in 1 minute
80 Fully coagulated in 1 minute
100 No sign of coagulation after 15 minutes
Note : The same study was repeated using boiled ginger juice and the milk
did not coagulate at any temperature.

(i) Referring to the above results, describe the effect of milk temperature
on the rate of milk coagulation by ginger juice. (3 marks)

(ii) How would you explain the action of fresh ginger juice in bringing
about the coagulation of milk ? Give evidence to support your answer.
(2 marks)

(iii) Milk protein also coagulates at low pH. In which part of the
alimentary canal does this coagulation occur ? Based on your
biological knowledge, suggest why the coagulation of milk protein can
facilitate its digestion in that part of the alimentary canal. (3 marks)

END OF PAPER

−18−
2002-CE-BIO 1–19

Ce Biology 2002 Paper1(E)

Recommended

Recommended

More Related Content

What's hot

What's hot (9)

Similar to Ce Biology 2002 Paper1(E)

Similar to Ce Biology 2002 Paper1(E) (20)

More from cyt03163

More from cyt03163 (6)

Recently uploaded

Recently uploaded (20)

Ce Biology 2002 Paper1(E)