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Anglo-Chinese School (Independent)
YEAR FOUR EXPRESS MID-YEAR EXAMINATION
CENTRE INDEX
S 2 0 3 1
NUMBER NUMBER
BIOLOGY 6093/02
Paper 2 6 May 2019
1 hour 45 minutes
No Additional Materials are required.
READ THESE INSTRUCTIONS FIRST
DO NOT OPEN THIS QUESTION BOOKLET UNTIL YOU ARE TOLD TO DO SO.
Write your index number on all the work you hand in.
Write in dark blue or black pen. You may use a pencil for any diagrams, graphs or rough working.
Do not use correction fluid or tape.
Electronic calculators may be used.
This paper consists of two sections:
For Examiner’s Use
Section A
Answer all questions.
Write your answers in the spaces provided on the question paper.
Section A
Section B Section B
Answer all questions.
Write your answers in the spaces provided on the question paper.
Write an E (for Either) or an O (for Or) next to the number 10 in the grid to
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indicate which question you have answered.
9
.
You are advised to spend no longer than one hour on Section A and 10
no longer than 45 minutes on Section B.
At the end of the examination, fasten all your work securely together TOTAL /80
The number of marks is given in brackets [ ] at the end of each question
or part question
“The things, good Lord, that I pray for, give me thy grace to labour for. Amen.”
Excerpt from “A Devout Prayer”
by
Sir Thomas More
A.D. 1535
This document consists of 18 printed pages, including this cover page.
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Section A
Answer all questions.
Write your answers in the spaces provided.
1 Fig. 1.1 shows the events that happen after a cut to the skin of a person.
Fig. 1.1
(a) Describe what happens after the cut that led to the formation of a blood clot 24 hours
after the cut.
[3]
(b)(i) Explain the presence of phagocytes below the blood clot 24 hours after the cut.
[1]
3
(ii) Explain the role of lymphocytes in the action of phagocytes in (b)(i).
[1]
(c) Explain how mitosis help in repairing the skin tissue.
[2]
[total: 7]
2 Red blood cells and cells making up the one-cell thick walls of blood capillaries have special
proteins called antigens on their cell membranes that stimulate the production of antibodies.
These antigens determine the blood groups of a person.
(a) When carrying out kidney transplants between human donors and recipients, it is
important to check that the blood group of the donor matches the blood group of the
recipient.
However, corneas can be successfully transplanted without checking the blood group of
the donor and the recipient.
Suggest why it is possible to transplant corneas successfully without checking the blood
groups.
[1]
(b)(i) One allele controlling human blood group is IA.
State the other two alleles that control the blood groups in humans.
[1]
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(ii) A person with blood group O has parents with blood groups A and B.
Complete the genetic diagram below to show how this is possible.
parental phenotypes blood group A X blood group B
parental genotypes X
gametes
random fertilisation
offspring genotype
offspring phenotype
[3]
(iii) Complete Table 2.1 for the alleles controlling human blood groups. The first one has
been done for you.
Table 2.1
term example
a dominant allele IA
heterozygous genotypes
codominant alleles
recessive allele
[2]
[total: 7]
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3 Fig. 3.1 shows the parts of a plant growing above ground.
Fig. 3.1
(a) Suggest why it is an advantage for the plant to reproduce by each of the following
methods:
(i) flowers
(ii) plantlets
[2]
Fig. 3.2 shows a pollen grain with a pollen tube growing from it.
Fig. 3.2
Pollen grains from the same type of plant were placed in sucrose solutions of different
concentrations for a fixed amount of time. After this time, the pollen grains and tubes were
examined using a microscope. The following observations were made for each concentration
of sucrose:
• the number of pollen grains that had germinated to produce a pollen tube,
• the length of each pollen tube.
Table 3.1 on the next page shows the results of the investigation.
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Table 3.1
% sucrose % of pollen grain mean pollen tube
concentration germinated length/ mm
1 6 0.005
2 13 0.008
4 25 0.015
8 56 0.040
10 31 0.030
20 25 0.018
40 13 0.006
(b) The germination of a pollen grain to form a pollen tube requires the movement of water
into the pollen grain from its surroundings.
Suggest why placing a pollen grain in a solution with a high sucrose concentration may
result in a lower percentage of germination.
[3]
(c) Describe the route taken by a growing pollen tube in a plant and explain its importance
in plant reproduction.
[4]
[total: 9]
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4 (a) The production of human gametes involves meiosis.
State two reasons why meiosis is suitable for gamete production.
[2]
(b) Explain how the sex of a human fetus is determined when gametes fuse.
[3]
Fig. 4.1 shows a human fetus developing inside the uterus.
Fig. 4.1
(c) State the concentration of progesterone in the blood of the woman from the moment she
got pregnant to the moment shown in Fig. 4.1.
[1]
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(d) Describe how the structures named in Fig. 4.1 are involved in the excretion of metabolic
waste of the fetus.
[2]
[total: 8]
5 Complete Table 5.1 by filling in the blanks.
Table 5.1
location of enzyme
enzyme substrate product(s)
secretion
ileum glucose
trypsin protein
amino acids
starch
[5]
[total: 5]
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6 Fig. 6.1 shows a specialised cell from the pancreas that secretes the hormone insulin. Insulin is
a peptide hormone.
Fig. 6.1
(a) Label with its correct names on Fig 6.1, two organelles involved in the synthesis of
insulin. [2]
(b) Explain what is meant by the term hormone.
[3]
(c) Outline the steps involved in using bacteria to produce human insulin.
[4]
[total: 9]
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7 Fig. 7.1 shows the human thorax.
Fig. 7.1
(a) Describe how each of the structures named in the diagram is involved when a person
shouts loudly.
[3]
(b) Fig. 7.2 shows two magnified structures, D and E, from the thorax.
Fig. 7.2
Draw lines labelled D and E on Fig. 7.1 to indicate the positions of structure D and structure E.
[2]
[total: 5]
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Section B
Answer three questions.
Question 10 is in the form or an Either/ Or question. Only one part should be answered.
8 Human skin is a sense organ containing sensory receptors that can detect touch.
(a) A student carried out an experiment to determine the minimum distance between two points that
can be sensed on the skin of the index finger, palm, forearm, upper arm and shoulder of another
student, whose eyes were covered with a blindfold.
The blindfolded student then removed his blindfold and gave it to the other student who used it
to cover his eyes. All the previous tests were then carried out on this second student.
The mean results for the two students are shown in Table 8.1.
Table 8.1
mean minimum distance
area of skin
detected as two points/ mm
index finger 2
palm 14
forearm (between wrist and elbow) 32
upper arm (between elbow and shoulder) 38
shoulder 42
(i) Plot the data in Table 8.1 in a suitable format on the grid below.
[4]
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(ii) Explain why the students tested each other and calculated a mean result.
[1]
(iii) Suggest one other variable that the students should control to ensure that their results are valid.
[1]
(iv) Suggest reasons for the different sensitivity of these areas of the skin.
[2]
(b) When a person accidentally touches a very hot surface with his hand, he will immediately
withdraw his hand from the hot surface.
Explain how parts of a reflex arc bring about this response.
[5]
[total: 13]
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(a) Glucose in the blood is absorbed by liver cells and muscle cells. These cells convert glucose to
glycogen for storage.
Explain why glucose needs to be converted to glycogen for storage rather than dissolved in the
blood.
[3]
(b) Starch is a carbohydrate stored inside plant cells.
Explain why starch is more suitable for storage than glucose.
[3]
(c) State what happens to excess amino acids in the blood of a person.
[1]
[total: 7]
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10 Either
(a) Describe and explain how each of the following affects the rate of photosynthesis:
light intensity
air temperature
[7]
(b) Explain how animals are dependent on the process of photosynthesis.
[3]
[total: 10]
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10 Or
(a) Describe and explain how each of the following is important in the functioning of a human eye:
choroid
ciliary muscles
[7]
(b) Cataracts is the painless clouding of the lens in the eye.
Explain how a person’s vision is affected when a person has cataracts.
[3]
[total: 10]
End of Paper
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Additional writing space
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Source of images:
Q1: 0610_s12_qp31_Q1
Q3: 5090_w18_qp21_Q1 & 5090_w18_qp22_Q3
Q4: 0610_s13_qp33_Q5
Q7: 5090_w18_qp21_Q4
