Download marking scheme

PRESBYTERIAN HIGH SCHOOL
BIOLOGY
5094/1
PAPER ONE
10 July 2008
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
Thursday
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
1 hour
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
2008 SECONDARY FOUR EXPRESS
PRELIMINARY EXAMINATION 1
INSTRUCTIONS TO CANDIDATES:
Write in soft pencil.
Do not use staples, paper clips, highlighters, glue or correction fluid.
Write your name, class and register number on the answer sheet in the spaces
provided.
There are forty questions on this paper. Answer all questions. For each question
there are four possible answers, A, B, C and D.
Choose the one you consider correct and record your choice in soft pencil on the
separate answer sheet.
Read the instructions on the Answer Sheet very carefully.
Each correct answer will score one mark. A mark will not be deducted for a wrong
answer.
Any rough working should be done in this booklet.
Setter: Mr Chandrasegaran P
This question paper consists of 16 printed pages including this cover page.
For each question there are four possible answers, A, B, C and D. Choose the
one you consider correct and record your choice in soft pencil on the separate
answer sheet.
1.
The diagram shows an electromicrograph of an animal cell that has some
organelles and membrane system labelled.
Y
Z
Which gives the correct identifications?
A
B
C
D
2.
W
mitochondrion
ribosome
ribosome
vacuole
X
vacuole
Golgi body
mitochondrion
Golgi body
Y
Golgi body
mitochondrion
vacuole
ribosome
Z
ribosome
vacuole
Golgi body
mitochondrion
When radioactive-labelled amino acids are taken up by secretory cells, what is
the sequence of structures in which radioactivity will appear?
A
B
C
D
first ------------------------------------------------------------------ last
endoplasmic reticulum
vesicle
Golgi apparatus
vesicle
endoplasmic reticulum
vesicle
Golgi apparatus
vesicle
endoplasmic
reticulum
endoplasmic reticulum
Golgi apparatus
vesicle
2
3.
The diagrams below show different kinds of xylem vessels.
Which of the following features of xylem vessels is most important in allowing it to
carry out its main function effectively?
A
B
C
D
4.
They have cellulose cell walls.
They have cell walls thickened with lignin.
They form a long continuous hollow channel from the roots to the leaves.
They have a large lumen with no protoplasm.
Which group of cells, taken from the same plant, has been placed in hypotonic
solution than the cell contents?
3
5.
The apparatus was set up as shown in the diagram.
After 30 minutes had elapsed, the partially permeable tubing containing liquid Y
had collapsed while the tubing containing liquid Z was firm.
Which could be a correct description of the liquids at the start of the experiment?
A
B
C
D
6.
liquid X
10% sucrose solution
25% sucrose solution
water
10% sucrose solution
liquid Y
water
10% sucrose solution
25% sucrose solution
25% sucrose solution
liquid Z
25% sucrose solution
water
10% sucrose solution
water
Strips of potato tissue were immersed in a range of sucrose solutins of different
concentrations. Their lengths were measured before immersion and after 30
minutes in the different solutions. The graph below shows the ratio of initial length
to final length.
Which concentration of sucrose solution has the same water potential as cell sap?
A
0.1
B
0.25
C
0.45
D
0.6
4
7.
The diagram illustrates energy changes in an enzyme controlled reaction.
Which of the following represents the lowering of the activation energy?
A
8.
Y
B
C
X+Y
D
Z-Y
Which graph shows the expected relationship between enzyme activity and
substrate concentration?
A
9.
Z
B
C
D
Which one of the following combinations of statements is true of polysaccharides
in living organisms?
A
B
C
D
they provide
energy
No
No
Yes
Yes
they form storage
compounds
No
No
Yes
Yes
they form supporting
structures
Yes
No
No
Yes
5
10. The diagrams below represent molecules of starch, protein and fat.
Which of the following mix of molecules will be found in the stomach?
11. The table shows the results of an investigation into the absorption of products of
digestion in the presence and absence of oxygen.
products of
digestion
amino acids
fatty acids
glucose
glycerol
absorption in the presence of
oxygen/arbitrary units
5.3
1.9
6.4
4.8
absorption in the absence
of oxygen/arbitrary units
1.7
2.0
2.3
4.7
Which conclusion can be drawn from these results?
A
B
C
D
All products of digestion are absorbed by both active transport and diffusion.
All products of digestion are absorbed by diffusion only.
Amino acids and glucose are absorbed by active transport only.
Fatty acids and glycerol are absorbed mainly by diffusion.
6
12. A medical scientist investigates four species of insects. He knows that one feeds
on human blood and that the others feed on plants. As the insects look similar, he
investigates the digestive enzymes present in their guts.
Which insect feeds only on blood?
insect
A
B
C
D
enzyme present in insect guts
amylase
lipase
protease
sucrase
Yes
No
Yes
Yes
Yes
No
No
Yes
No
Yes
Yes
No
No
Yes
No
No
13. Liver functions include
J
K
L
M
N
breakdown of red blood cells and excess haemoglobin
formation and breakdown of fatty acids
inter-conversion of glucose to and from glycogen
glycerol formation from excess sugars
urea formation by breakdown of excess amino acids
Which correctly shows the roles of the liver in fat metabolism?
A
B
C
D
K only
K and M only
J, L and M only
J, K, L and N only
14. Which of the following is an energy-rich carbohydrate stored in large quantities in
liver and muscle cells?
A
B
C
D
Glucose
Glycogen
Haemoglobin
Starch
15. The diagram shows part of the human alimentary canal. Which two structures
produce substances involved in digestion of fat?
A
B
C
D
1 and 5
2 and 3
3 and 4
4 and 5
7
16. The table shows the blood groups of four people and the type of blood each
received in a transfusion.
Which person is at risk from agglutination?
A
B
C
D
blood group
(under ABO system)
A
B
AB
O
blood type received in
transfusion
O
AB
B
O
17. The graph shows the pressure changes in the aorta and the left side of the heart
during one cardiac cycle.
At which points do AV and aortic valves close respectively?
A
W and Y
B
W and Z
C
X and Y
D
X and Z
18. Which is a definition of translocation?
A
B
C
D
movement of gas molecules through the air spaces in a leaf and through the
stomata
movement of nitrate ions from sites of active uptake to sites where protein
synthesis is occurring
movement of the products of photosynthesis from sites of production to
storage sites
movement of water through a plant as a consequence of gaseous exchange
in the plant
8
19. Under which circumstances will lactic acid accumulate in muscle?
A
B
C
D
concentration of carbon dioxide
too high
too high
too low
too low
supply of oxygen
less than oxygen demand
more than oxygen demand
less than oxygen demand
more than oxygen demand
20. Carbon dioxide turns limewater cloudy (milky).
Which one of the following would demonstrate that expired air contains much
carbon dioxide?
21. Which process does not require energy?
A
B
C
D
Contraction of muscles
Synthesis of proteins
Tissue respiration
Transmission of nerve impulses
9
22. The trigeminal nerve in humans connects the brain with the teeth and with the skin
of the face. When the dentist administers a local anaesthetic by injection, you can
no longer feel pain and you cannot smile properly. This allows you to conclude
that
A
B
C
D
the trigeminal nerve contains both motor and sensory neurones.
the trigeminal nerve contains mainly sensory neurones.
the trigeminal nerve contains mainly motor neurones.
the trigeminal nerve carries impulses from the brain to the teeth and back to
the brain
23. The diagram shows a simple reflex arc. A cut has been made along line x---x
What is the effect of this cut on feeling the pin and on the reflex movement of the
arm?
A
B
C
D
pin felt
No
No
Yes
Yes
reflex arm movement
No
Yes
No
Yes
24. The flow diagram shows the pupil reflex.
10
Which words complete the flow diagram?
A
B
C
D
X
motor
motor
sensory
sensory
Y
ciliary body
iris
ciliary body
iris
Z
contracting
relaxing
relaxing
contracting
25. During a school swimming meet, a time-keeper saw the swimmers approaching
the finishing end. He looks at this stop-watch and checks with the swimming
complex clock tower. Which of the following sequences of changes occurs in the
shape of the lens of his eye?
A
B
C
D
26. Which part of the eyeball produces the greatest degree of refraction of light?
A
B
C
D
aqueous humour
cornea
lens
vitreous humour
27. Which describes an expect of the role of the anti-diuretic hormone?
A
B
C
D
It is antagonistic to insulin.
It controls the rate of secretion of water in sweat.
It regulates osmotic concentration of body fluids.
Its absence causes diabetes mellitus.
28. Long term kidney failure can be treated by introducing sterile dialysis fluid into
the abdominal cavity. The fluid is drained and replaced regularly using a tube
inserted surgically through the abdominal wall.
This method works well
A
B
C
D
because osmoregulation and excretion are achieved by diffusion
between the blood in the abdominal capillaries and the dialysis fluid.
because osmoregulation and excretion are achieved by the active
transport of ions,water and urea between the abdominal capillaries
and the dialysis fluid.
because the fluid is in direct contact with the kidneys, and urea and
excess ions can pass into it without being filtered.
because the fluid is in direct contact with the liver and the large intestine
and wastes and excess ions can pass into it from these organs.
11
29. In a dialysis machine, all the following would take place except
A
B
C
D
blood cells are prevented from leaving the kidney.
blood flows through a tube with partially permeable walls.
diffusion of solutes into the surrounding.
selective reabsorption of salts.
30. The diagram below represents a kidney nephron.
In a healthy person, which structure would contain most amino acids?
A
B
C
D
1 and 2
3 and 4
4 and 5
5 and 6
31. The diagram shows a side view of the female reproductive system. In which
region are sperms released during intercourse and where does the fusion of
sperm and egg usually take place?
A
B
C
D
sperms released
1
1
4
4
fusion of egg and sperm
2
3
2
3
12
32. In the diagram, P and Q are gametes which fuse to give cell R. Cell R then
produces gametes S, T, U and V.
Which statement about the numbers of chromosomes in the cells and gametes is
correct?
A
B
C
D
The numbers of chromosomes in P and Q are different.
The numbers of chromosomes in P and S are the same.
The numbers of chromosomes in S is one quarter of the number of
chromosomes in R.
The number of chromosomes in T is half the number of chromosomes in Q.
33. Which of the following changes in the menstrual cycle is due to pregnancy?
A
B
C
D
Oestrogen secretion peaks and remains high.
Ovulation is prevented from occurring.
Progesterone secretion decreases and remains low.
Uterus lining is repaired.
34. A pyramid of numbers in an ecosystem on land may be represented as shown
below.
Which organisms are smallest in size?
13
35. Which box contains only the parts of an ecosystem that are grouped as a food
web?
36. In the diagram, arrows represent the movements of carbon compounds in
the carbon cycle. The circles represent carbon compounds in animals,
decomposers, plants and the atmosphere.
Which identifies each circle?
A
B
C
D
1
animals
atmosphere
decomposers
plants
2
decomposers
plants
animals
atmosphere
3
plants
decomposers
atmosphere
animals
4
atmosphere
animals
plants
decomposer
14
37. The diagram shows a sewage treatment process.
Which stage involves anaerobic bacteria?
38. The diagram shows part of a river into which sewage is being dumped.
Some of the effects of adding sewage to the river are shown in the graph.
At which point in the river are decomposers most active?
15
39. The graph shows the amount of DNA in the nucleus of cells dividing by meiosis.
What stages do X and Y represent?
A
B
C
D
X
metaphase I
prophase I
telophase I
telophase I
Y
telophase I
telophase II
metaphase II
telophase II
40. The diagram shows anaphase I of meiosis.
Which diagram shows metaphase II as meiosis continues in this cell?
A
B
C
D
END OF PAPER
16
Name: ...................................... Register/Index Number: ...............
Class: ..............
PRESBYTERIAN HIGH SCHOOL
BIOLOGY
5094/2
PAPER TWO
9 July 2008
Wednesday
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
1 hour 45 minutes
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
PRESBYTERIAN HIGH SCHOOL
2008 SECONDARY FOUR EXPRESS
PRELIMINARY EXAMINATION 1
INSTRUCTIONS TO CANDIDATES:
Write class, register number and name on all the work you hand in.
Write in dark blue or black pen.
Do not use correction fluid.
Section A
Answer all questions.
Write your answers in the spaces provided on the question paper.
Section B
Answer all questions.
Write your answers on the foolscap paper provided.
At the end of the examination, fasten all your work securely together.
Information for candidates
The number of marks is given in brackets [
question or part question.
For Examiner’s Use
Section A
] at the end of each
You are advised to spend no longer than 45 minutes on Section A
and no longer than one hour on Section B.
Section B
Total
Setter: Mr Chandrasegaran P
This question paper consists of 11 printed pages including this cover page.
17
SECTION A
Answer all questions in this section.
Write your answers in the spaces provided.
1.
Fig. 1A and 1B are drawings from electron micrographs of cells from the lining of
the human gut.
Cell A secretes large amounts of the protein pepsinogen into the stomach.
Cell B is from the lining of the small intestine. This type of cell is responsible for
the uptake both by diffusion and active transport of the soluble products of
digestion.
Cell B
S
Fig. 1A
Fig. 1B
a.
Complete the table below by listing three ways in which the structure of
cell A differs from that of cell B.
[3]
cell A
cell B
1
2
3
18
b.
Explain the significance of the labelled structures for the particular
functions of:
i.
cell A
P:
[2]
................................................................................................
................................................................................................
Q:
................................................................................................
................................................................................................
ii.
cell B
R:
[2]
................................................................................................
................................................................................................
S:
................................................................................................
................................................................................................
[Total: 7]
2.
The figure below shows a shoot of a destarched plant at the start of a ringing
experiment on the movement of substances within a plant. In two places on the
stem, Y and Z, tissue was removed as in the enlarged sections shown below.
Y
shaded
tissues
removed
Z
The plant was left in sunlight for six hours, after which it was noticed that there
was more water on the inside of bag C than on the inside of bag D.
a.
i.
Name the process carried out by the leaves that was responsible
for the water inside the bags.
………………………………….
[1]
19
ii.
Suggest how the appearance of leaf E might differ from that of leaf
G. Explain your answer.
.........……………………………………………….................................
...........................................................................................................
................…………………………………………………………........[3]
b.
After six hours, leaves F and G were tested for the presence of starch.
Both leaves were found to contain starch.
Explain how leaf G was able to make starch even though the leaf was
enclosed in a bag and tissue had been removed from the stem at Z.
..............………………………………………………………………………......
……………………………………………………………………………………..
……………………………………………………………………………………..
………………………………………………………………………………......[3]
c.
A similar ringing experiment was tried by a fruit grower attempting to
produce unusually large pears.
20
The table below shows the total mass of the three pears per branch
several months later.
i.
Complete the table and complete it by matching the four sets of
results with the four branches.
[2]
total mass of
three pears per
branch
75 g
branch
number
300 g
525 g
750 g
ii.
Provide an explanation of the results you have provided in the table
above.
...........................................................................................................
...........................................................................................................
...........................................................................................................
.......................................................................................................[2]
[Total: 11]
3.
Fig. 3.1 shows the analogy of our body’s temperature regulating mechanism to
that of an oven thermostat which switches on and off to adjust the temperature
as desired.
Fig. 3.1
a.
With reference to the diagram, explain what is meant by the term negative
feedback.
......................................................................................................................
......................................................................................................................
..................................................................................................................[2]
21
b.
In the human body, name the ‘thermostat’ for temperature regulation.
..................................................................................................................[1]
c.
Describe and explain the working of two regulating mechanisms that
would be turned on when the human body temperature rises above
normal.
......................................................................................................................
......................................................................................................................
......................................................................................................................
......................................................................................................................
......................................................................................................................
......................................................................................................................
......................................................................................................................
..................................................................................................................[5]
d.
Compare the mechanism by which blood glucose concentration is
regulated with temperature control system in our body.
......................................................................................................................
......................................................................................................................
......................................................................................................................
......................................................................................................................
..................................................................................................................[3]
e.
Suggest how the human body is similar or different to the oven in losing
heat to the environment when the body temperature is above normal.
......................................................................................................................
......................................................................................................................
......................................................................................................................
................................................................................................................. [2]
[Total: 13]
22
4.
Fig 4.1 shows how Dolly the sheep was cloned
Fig 4.1
a.
Name the type of cell division that occurs:
i.
as the egg cell is produced
.
ii.
.......................................................................................................[1]
as the fused cell begins to divide normally.
.......................................................................................................[1]
b.
State how cell division in part (aii) maintains genetic stability in an
organism.
......................................................................................................................
......................................................................................................................
......................................................................................................................
......................................................................................................................
..................................................................................................................[3]
c.
Is the production of Dolly in Fig 4.1 sexual or asexual reproduction?
Explain the reason for your answer.
......................................................................................................................
..................................................................................................................[2]
23
d.
Sex in sheep is inherited in the same way as in humans. With reference
to sex chromosomes, suggest and explain the sex of Dolly.
......................................................................................................................
......................................................................................................................
......................................................................................................................
..................................................................................................................[2]
e.
Suggest one advantage of placing the embryo in the uterus of a foster
sheep.
......................................................................................................................
..................................................................................................................[1]
[Total: 10]
5.
A survey was carried out to determine if smoking during pregnancy affects the
birth mass of babies.
The graph shows the results of the survey.
a.
How many babies were examined in the survey?
..................................................................................................................[1]
b.
How many babies with a birth mass of less than 3.0 kg were born to
women who smoked 20 or fewer cigarettes per day?
..................................................................................................................[1]
c.
What is the relationship between the number of cigarettes smoked per
day and the birth mass of babies?
......................................................................................................................
..................................................................................................................[1]
24
d.
Explain how smoking cigarettes may lead to a change in the birth mass of
babies.
......................................................................................................................
......................................................................................................................
......................................................................................................................
......................................................................................................................
......................................................................................................................
..................................................................................................................[4]
e.
Suggest and outline a method used to establish the association between
smoking tobacco and lung diseases, such as cancer.
......................................................................................................................
......................................................................................................................
..................................................................................................................[2]
[Total: 9]
End of Section A
25
SECTION B
Answer all questions including questions 6, 7 and 8 Either or 8 Or.
6.
Fig. 6.1 shows the changes in blood pressure, mean velocity of blood flow and
the total cross-sectional area of the blood vessels of the systemic circulation as
blood flows and returns to the heart.
Fig. 6.1
a.
State the relationship between the velocity of the blood flow and the total
cross sectional area of the blood vessels.
[1]
b.
i.
Comment on the rate of blood flow through the capillaries.
[2]
ii.
Explain the significance of this in relation to the function of the
capillaries.
[1]
c.
d.
e.
What is the greatest change in pressure recorded in
i.
large arteries and
ii
left ventricle?
Explain why pressure fluctuates less in large arteries than in the left
ventricle.
[2]
[2]
Describe the sequence of events which occurs during the cardiac cycle.[4]
26
7.
The table below shows some of the activities on a farm.
Describe and explain the possible effects of these activities on wild plants and
animals living near the farm.
[8]
EITHER
8.
a.
The placenta has many roles during pregnancy. For example, maternal
and fetal blood are prevented from mixing but digested nutrients pass
across the placenta to the fetus.
Suggest why leakage of blood in either direction across the placenta
might harm the fetus.
[5]
b.
The spread of human immuno-deficiency virus (HIV) is a worldwide
problem.
Describe clearly how the disease can spread in a community and suggest
public health measures that could be taken to reduce the spread of HIV.
[5]
a.
Explain two similarities and two differences in the way in which an alveolus
of the lung and a villus of the intestines are each adapted to their respective
functions in a mammal.
[4]
b.
Explain how the diaphragm and intercostals muscles are involved in the
process of breathing.
[6]
OR
8.
END OF PAPER
27
PRESBYTERIAN HIGH SCHOOL
SCIENCE DEPARTMENT
MARKING SCHEME
Subject:
Prelim 1
Setter :
: 2008
Level :
Biology
Exam:
Mr Chandra
Year
Sec
4E
Q/N
Scoring Points
Sub
Total
Total
PAPER 1
1
2
3
4
5
6
7
8
9
10
C
D
C
B
A
C
D
B
D
22
11
12
13
14
15
16
17
18
19
20
D
C
B
B
C
B
A
C
A
D
21
22
23
24
25
26
27
28
29
30
C
A
A
D
B
B
C
A
A
A
31
32
33
34
35
36
37
38
39
40
C
B
B
A
B
C
B
B
B
B
40
PAPER 2, SECTION A
1a
A
many, large vesicles/vacuoles
few mitochondria
microvilli absent
a lot of golgi apparatus
bi
2ai
ii
b
ci
ii.
B
smaller and fewer
numerous
microvilli present
few golgi appratus
1
1
1
1
P: to transport protein, enzyme from the cell to exterior;
Q: produces the protein/ modifies and packages proteins before
secretion;
1
R: increase surface area for absorption;
S: provide energy for active transport during absorption of nutrients
1
1
transpiration
leaf appear wilted;
xylem/vascular bundles removed;
no water transported to leaves;
transparent bag allows light to reach leaves;
phloem removed but xylem intact;
it supplies water;
perforated bag allows carbon dioxide to enter and used by leaf.
3, 4, 1, 2
Food/sugars manufactured in leaves and carried in phloem cells;
ring removes phloem;
those pears on the right do not receive the sugars.
3
1
4
1
1
1
1
½
1
1
½
1
½ ea
1
½
½
2
3
3
2
28
3a.
b
c
d
e
4ai
ii
b
c
d
e
5a
b
c
d
e
if a body system is disturbed/ detects changes;
it responds/reacts to bring about an opposite effect;
restore to original state;
hypothalamus;
vasodilation of capillaries; + shunt vessels constrict;
more blood flow in capillaries near skin;
heat lost by radiation, convection;
sweat glands active/stimulated;
more sweat produced;
water in sweat evaporates;
removes latent heat.
½
1
½
1
1
½
1
1
½
½
½
blood glucose not regulated by hypothalamus but pancreas;
control by hormones not nervous system;
both involve a negative feedback;
both require a stimulus;
1
1
1
1
3
similar: heat lost by convection, radiation;
difference: skin heat lost by evaporation/sweating
1
1
2
meiosis
mitosis
replication of DNA during interphase;
all genes copied exactly;
no crossing over;
no pairing of homologous chromosomes or random distribution of
chromosomes;
therefore no genetic variation
1
1
2
asexual
no fusion of gametes
same sex as sheep X;
nucleus containing sex chromosomes is from sheep X.
uterine lining of sheeps X and Y may not be ready for implantation;
the sheeps may be too old for reproduction;
the sheeps may be under stress;
1
1
1
1
25
6
more cigarette smoked, lower the birth mass of baby;
Carbon monoxide in cigarette smoke;
passes from mother to babies blood;
combines with haemoglobin/forms carboxyhaemoglobin;
less oxygen carried in rbc;
less/reduced growth of fetus;
1
1
1
1
1
1
1
1
people undergoing treatment for lung diseases;
how many are smokers or have been smokers;
check for correlation;
1
1
2
1
5
1
1
1
4
2
examine death statistics;
people who died of respiratory illness and are smokers;
check for correlation;
29
6a
bi
ii
SECTION B
velocity of blood flow is inversely proportional to the cross sectional
area;
the larger the cross sectional area, the smaller the velocity;
rate of blood flow in capillaries is the lowest/slowest;
attributed to capillaries have the largest cross sectional area
allows more time for exchange of materials like glucose, oxygen b/w
blood and tissues
ci
ii
4 - 5 kPa
13 - 14 kPa
d
ventricle
it undergoes systole and diastole;
repeated contraction and relaxation of cardiac muscles;
arteries
only elastic collagen fibres only stretch and recoil to force blood
forward in spurts; so less fluctuation
e
7
atrial systole : both atria contract, ventricles relaxed;
AV open, blood from atria forced to ventricles;
ventricular systole: ventricles contract, atria relax;
AV closes (lub sound), blood forced to aorta and pulmonary artery;
difference in pressure causes semilunar valves to open;
diastole: atria and ventricles relaxed;
AV open, blood enters atria from venae cava and pulmonary veins;
semilunar valves closes (dub sound);
1
1
1
1
1
1
1
1
1
1
1
1
1
1
½
½
½
½
½
½
½
½
4
½
½
½
½
1
½
½
½
insecticide may drift through air + kill other insects;
insect eating animals have less food;
insecticide if non-degradable remains in leaves/soil
accumulate / concentrate up the food chain; biomagnification
last consumer receive fatal dose;
½
½
½
½
½
weed killer drift + kill surrounding plants;
shortage of food;
weed killer may remain in soil;
½
½
½
8
blood pressure of mother is higher than fetus;
either damage blood capillaries and may kill foetus;
incompatible blood groups; blood from foetus causes reaction in mum
maternal antibodies may cause fetus blood to agglutinate, block blood
2
1
Fertilisers added several times during the year;
leaching during rain;
reference to eutrophication;
nitrates and phospahtes cause rapid growth of plants in river;
dense growth + competition for light;
many die + decomposed by bacteria;
bacteria respires + uses oxygen;
other aquatic animals suffocate;
ploughing stubble increases organic content of soil;
1
½
8
1
1
1
1
30
b.
8or
vessels leading to death;
drugs like alcohol, nicotine, pathogens may reach foetus;
results in mental and physical abnormality;
maternal hormones can also affect the development of the foetus;
1
1
1
-exchange of contaminated body fluids like semen, blood;
-misuse of drugs ref to intravenous drug abuse;
-HIV positive people show no symptoms/signs so spreading is faster;
1
1
1
-use of condom;
-no sharing of syringes for intravenous drug use;
-screen all blood donors;
-public education, elaborate;
1
1
1
1
similarity:
-large surface area to volume ratio for faster rate of
absorption/diffusion of materials;
-rich supply/network of blood capillaries;
constant flow of blood maintains a steep diffusion gradient
-alveolar wall and epithelium of villus is 1 cell thick; easy/fast diffusion
of materials;
differences:
-alveolus has thin film of moisture for gases to dissole;
villi already in aqueous medium / intestinal fluid;
-gas exchange in alveolus is by simple diffusion only;
absorption in villus involves simple diffusion, active transport and
osmosis;
b.
diaphragm contracts + flattens;
intercostals muscles contract;
ribs and sternum move outwards and upwards;
thoracic cavity volume increases;
increased volume in lungs;
air pressure greater outside than in lungs;
air pressure forces air into lungs. (reject air sucked in)
5
5
1
1
1
1
1
4
1
1
1
1
1
1
1
6
31
PRESBYTERIAN HIGH SCHOOL
2008 PRELIMINARY EXAMINATION 1 MARKER’S REPORT
BIOLOGY
PART 1
PERFORMANCE
CLASS
% PASS
% DISTINCTION
AVERAGE MARK
Candidate
4E
85
25.6
4G
71.2
5.1
4H
30.8
0
39
39
39
PART 2
DETAILED COMMENTS
Section A - MCQ
The following questions had more than 50% incorrect responses:
Q2, 3, 4, 9, 12, 13, 17, 21, 26, 27, 34, 35, 39, 40
Section B - Short answer & Structured questions
Q1. Comparison was badly done. Candidiates used a few and absent as if they meant
the same. Very few used the term micrvilli, forgetting that the cells are single cells.
Some confusion between golgi apparatus and endo[lasmic reticulum.
Q2. The term perforated seems redundant, many mentioned that carbon dioxide from
respiration is sufficient for photosynthesis in the enclosed leaf. This may result in very
little starch or no sugar produced at compensation point.
2C. Very badly done. The understanding that phloem transports manufactured food
from the leaves was not clearly shown.
Q3. Definition of negative feedback was not clear, a large reference to adaptation to
changes rather than changes back to original condition was less mentioned.
3d. Candidates described what happens in liver in response to changing sugar levels.
Though involvement of hormones was indicated, no mention of the role of nervous
system.
3e. Merely copied from the diagram to say system shuts down. Candidates did not
appreciate that even if oven is shut down, the heating element has to lose heat by
radiation and convection.
Q4b. The term genetic stability was less understood.
4d. A large number described the role of sex chromosomes and how it is passed on
without the understanding that the nucleus was from sheep X which contained the sex
chromosomes.
4e. Reference to how nutrients are obtained was very common though the question
32
looked at why a foster/surrogate.
Q5. Carbon monoxide in cigarette smoke was rarely mentioned.
5e Many references to how lung cancer is caused rather than correlation studies.
Q7. There is still a lot of misunderstanding about eutrophication. This question was
badly done.
Q8 either
8b Spread of HIV was briefly discussed, the unqualified use of the term needles was
very common. No candidate mentioned that HIV positive individuals do not display
signs or symptoms as such may spread the virus unintentionally.
8 or
a
Hardly anyone used a table for comparison.
REPORT PREPARED BY : MR CHANDRA
DATE:
18 July 2008
33