2020
Primary 4 / Grade 4
Full Name:
School: Index Number:
Instructions to Students:
1. Please DO NOT OPEN the contest booklet until the Proctor has given permission to start
2. Only Scientific Calculators are allowed during the contest.
3. TIME: 1 hour 30 minutes. You may not leave the contest venue within the first hour of the paper.
4. There are 20 questions:
Section A: Question 1 to 5: +2 points for correct answer, 0 points for no answer and minus 1 point
for wrong answer.
Section B: Question 6 to 10: +3 points for correct answer, 0 points for no answer or wrong answer.
Section C: Question 11 to 20: +4 points for correct answer, 0 points for no answer or wrong answer.
5. Shade your answers neatly using a 2B lead pencil in the Answer Entry Sheet.
6. You are not allowed to bring the question paper and answer script out of the contest venue.
Note:
1) You may assume that there is no air resistance throughout the contest unless stated.
2) All temperatures are in Degrees Celsius.
3) Room Temperature is 25°C at 1 atmospheric pressure.
4) Gravitational Acceleration
Vanda 2020, Primary 4 (Grade 4) Contest
Section A (Correct answer – 2 points| No answer – 0 points| Incorrect answer – minus 1 point)
Question 1
The diagram below shows the classification hierarchy of the killer whale. Can sharks
and killer whales be grouped under the same phylum?
A. Yes, they are both mammals.
B. Yes, they are both vertebrates.
C. No, they are both different species.
D. No, they are from different classes.
Answer: B
Yes they are under the same phylum—chordata, which stand for animals with a
backbone, called vertebrates. Even though the shark is a fish and the killer whale is
a marine mammal, they are under the same phylum, however different classes.
Phylum is the bigger umbrella above class. Hence both sharks and killer whales
belong in the chordata phylum until further classified under ‘class’.
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 2
The animal show on the right has a backbone and has fur
on its body. It also has mammary glands to feed its young
with milk. The immature young after birth continues to grow
in the pouch of its mother.
Which class of animals does it belong to?
A. Aves
B. Amphibia
C. Actinopterygii
D. Mammalia
Answer: D
Mammalia means mammals. The key characteristics of mammals is that they give
birth to young alive, and feed its young with its milk. They also have hair or fur on
their bodies.
Question 3
Which of the following shows reproduction?
A. Iceberg melting into the ocean
B. A grasshopper moulting
C. Budding in yeast
D. A mother adopting a child.
Answer: C
Yeast reproduce by budding. This cell buds, the bud grows to nearly the size of the
parent cell, the nucleus divides, and the two cells separate into two unbudded cells.
Iceberg melting into the ocean is not an example of reproduction as icebergs are
non-living things going through a change in physical state. A grasshopper moulting
is not reproduction as it is merely shedding its old exoskeleton. A mother adopting a
child even though she is having a child she did not biologically reproduce to have
young.
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 4
Which of the following statements is/are true about all cycles?
1) The cycle repeats itself.
2) Living things undergo the changes.
3) There is no transfer of heat involved.
4) There can be a forward movement between stages as well as a backward
movement between stages.
A. Option 1 only
B. Options 1 and 2
C. Options 1, 3 and 4
D. Options 1, 2, 3 and 4
Answer: A
All cycles include life cycles and non-living cycles (e.g. water cycle, nitrogen cycle).
Only option 1 applies to all cycles as all cycles repeat themselves hence they are
called cycles. However, for non-living cycles, non-living things instead of living things
undergo the changes.
There is heat transfer involved between stages e.g. water cycle. In order for water
to evaporate it has to gain heat to change into gaseous state.
For life cycles, the stages can only move in one direction forward, i.e. from young to
adult. Hence option 4 cannot be correct.
Question 5
Martin wanted to find out if a brown paper bag or a Styrofoam™) box would be
better able to keep French fries crispy when ordering a takeaway.
He set up an experiment as described below.
He placed equal, weighed amounts of freshly fried French fries in a brown paper bag
and in a polystyrene foam (Styrofoam™) box.
Both were sealed and left undisturbed under same conditions for 10 minutes.
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Vanda 2020, Primary 4 (Grade 4) Contest
After 10 minutes, these were the results:
Brown paper bag Styrofoam box
At the start of the experiment Crispy Crispy
At the end of the experiment Relatively crispy Soft and soggy
From the above experimental results, he concluded that brown paper bags work
better when keeping French fries crispy.
What is the reason for this?
A. Paper is a good conductor of heat, allowing heat to pass through quickly so
that the French fries will cool down and not be softened and soggy.
B. Paper is a bad conductor of heat, not allowing heat to pass through it, hence
causing all the water in the paper bag to evaporate, keeping the French fries
crispy.
C. Paper bag used is thinner than polystyrene foam (Styrofoam™) and allows
the warm water vapour to escape before it condenses into water droplets. It
also absorbs the water droplets that have formed and prevent them from
touching the French fries.
D. Paper bag used is waterproof, and allows the water vapour to escape in
addition to retaining the water inside the bag. Hence the French fries remain
crispy.
Answer: C
Paper is not waterproof, it has the ability to absorb water. Here, it absorbs the water
droplets formed in the bag, preventing the French fries from becoming soggy upon
contact with the water droplets. It also allows the warm water vapour from the
French fries to escape as it is more porous than polystyrene foam
(Styrofoam™)Styrofoam, not allowing them to condense into water droplets which
may come into contact with the French fries and cause them to be soft and soggy.
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Vanda 2020, Primary 4 (Grade 4) Contest
Section B (Correct answer – 3 points| Incorrect or No answer – 0 points)
Refer to the following description for questions 6 and 7.
Fusarium oxysporum f. sp. cubense is a fungus in the Fusarium genus which is
currently threatening the banana plantations in the Caribbean coastal regions. It can
cause these banana plants to ultimately be unable to bear fruit or even survive. Most
of the time, it is lethal to the plant, even though it is not unsafe to humans. On a
larger scale, this can affect bananas as a food source, as well as an export
commodity. This fungus is transmitted through infected farming material, infested
soil and water, and this problem is also known as the Fusarium wilt.
Question 6
Which of the substances is/are not what the fungus is obtaining from the banana
plant?
1) Sunlight
2) Oxygen
3) Water
4) Nutrients
A. Options 1 and 4
B. Option 2 only
C. Options 1 and 2
D. Options 2, 3 and 4
Answer: C
Fungi and Bacteria require air, food and water to survive. As they are unable to
make their own food, they rely on the host to obtain their nutrients, like water and
food. They obtain oxygen from the surrounding air. They do not require sunlight to
survive. Only Options 1 and 2 are incorrect.
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 7
Joan observes that when the Fusarium oxysporum f. sp. cubense fungus infects the
plant, the leaves turn yellow and wilt, eventually, the plant does not survive. When
she had cut the stem of the plant, she observed that there were black strips in its
stem. A simple diagram of what she saw under the microscope has been provided
below. She was told that the fungus enters through the plant’s roots from the
infected soil and spread upwards thereafter.
Based on the information above, which of the statements is likely the key reason for
the death of the plant?
A. The fungus directly infects the leaves of the plant causing them to wilt. As
they wilt, they are no longer able to make food and exchange gases.
B. The roots produce black liquid and can no longer take in water and mineral
salts for the plant.
C. The phloem tissues are damaged and the food made by the leaves cannot be
sent to all parts of the plant.
D. The xylem vessels of the plant are damaged and obstructed, resulting in
restricted flow of water transported to the leaves.
Answer: D
Based on the information given, Joan observed that there are black strips in the
stem of the plant. This provides a clue as to the fact that the vascular bundle
(Phloem and xylem) of the plant has been infected. Based on the diagram, the inner
portion of the vascular bundle is observed to be darker (likely the black strips),
hence the deduction is that the xylem vessels have been infected.
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 8
Both plants below have roots with similar functions. The banyan tree is a huge
deciduous plant, and the screw pine grows in soft, sandy soil. What is the key
function of these two types of roots aside from taking in water and mineral salts?
A. The roots take in additional nutrients so that the plant can grow healthily.
B. The roots provide additional support to make sure that the plant is not easily
uprooted and is rooted firmly to the ground.
C. The roots contain additional xylem and phloem vessels and their main
function is to transport water, mineral salts and food throughout the plant.
D. The roots capture more sunlight so that the plant is able to make more food
for itself.
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Vanda 2020, Primary 4 (Grade 4) Contest
Answer: B
These roots are called aerial roots (for the banyan tree) and prop roots (for the
screw pine). Their main function is to give additional support to the plants. For the
banyan tree, it is a huge tree heavier on the canopy which and it is essential that it
has a good support for the entire canopy. For the screwpine, as it grows in sandy
soil, which can usually be easily eroded not providing good support for normal roots,
it has developed prop stilt roots to provide additional support to make sure the plant
is anchored to the ground.
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 9
Megan conducted an experiment for which she plucked some leaves from her
garden. She placed a fresh green leaf completely submerged into a glass beaker
containing hot water and then carefully observed it for 5 minutes. She noticed that
bubbles appeared on both sides of the leaves but most of the bubbles were found
appearing on the underside of the leaf.
What was the aim of her experiment?
A. She was trying to find out which surface of the leaves had more stomata.
B. She was trying to find out the amount of air present in the leaves.
C. She was trying to find out if there was exchange of gases happening in the
leaves.
D. She was trying to find out if air can expand.
Answer: A
When boiling hot water was added to the leaves, the air in the leaves expanded and
escaped from the stomata of the leaves. If the leaves had no stomata, bubbles
would not be seen. It is not possible to find out the amount of air present in the leaf
with such an experiment where no measurement was involved (e.g. using a method
to collect the gas that escaped and then measuring it). If Megan was trying to find
out if there was exchange of gases happening, she would have to do tests for gases,
e.g. glowing splint for oxygen and limewater for carbon dioxide. Trying to find out if
air can expand is not logically related to this experiment as this question involves
plants. A more relevant experiment involving a balloon filled with air and then
heated for e.g., is more suited to finding out if air can expand.
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 10
The diagram below is a communicating vessel. Which part(s) will be the first to fill
up when water is poured into A until the entire vessel is filled to the brim?
A B C D E
A. A and B will be the first to fill up.
B. E will be the first to fill up.
C. C, D and E will be the first to fill up.
D. None of the parts.
Answer: D
Water has no definite shape, and when it is poured into the container it takes the
shape of the container. Furthermore, for a communicating vessel, the bottom of the
vessel is connected, hence water flows evenly through the bottom even though it is
poured from A.
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Vanda 2020, Primary 4 (Grade 4) Contest
Section C (Correct answer – 4 points| Incorrect or No answer – 0 points)
Question 11
Yusef set up an experiment with 3 metal bars.
When Bar C was brought close to Bar B as shown in the diagram, he observed that
they were attracted to each other.
However, when he placed Bar C close to Bar A, both bars were not attracted to each
other and Bar C was pushed away from Bar A.
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Vanda 2020, Primary 4 (Grade 4) Contest
Which of the statements is/are correct?
1) Bar B could be a magnet or a magnetic material.
2) Bar A is made of copper.
3) C is definitely a magnet.
4) Bar B could be made of iron or nickel.
A. Option 3 only
B. Options 2 and 3
C. Options 1, 2 and 4
D. Options 1, 3 and 4
Answer: D
Only options 1, 3 and 4 are correct. If A and C push each other away, both have to
be magnets, as only magnets, when like poles are facing each other, will repel. If A
and C are magnets, Option 2 is definitely incorrect, and option 3 is definitely correct.
Since Bar B was attracted to Bar C (which we have established is a magnet), it can
be a magnet with an unlike pole facing the unlike pole of Bar C, or it can be a
magnetic material (iron, steel, nickel, cobalt). Either of which would mean it has to
be made of a magnetic material.
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 12
Yasothai had 4 iron nails, Nail T, Z, V and W. She used the stroking method to make
4 magnets. She then placed the magnetised nail close to a paper clip and measured
the distance, in cm, at which the magnetised nail was able to attract the paper clip.
No. of strokes Distance between nail and paper clip at
which paper clip was attracted (cm)
Nail T 30 5 cm
Nail Z 90 20 cm
Nail V 70 13 cm
Nail W 50 8 cm
Which nail was the strongest?
A. Nail V
B. Nail T
C. Nail Z
D. Nail W
Answer: C
Nail Z is the strongest as it has the greatest number of strokes and it was able to
attract the paper clip from a distance of 20 cm which was the furthest compared to
other nails.
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 13
Humans are able to see visible light, which can be split into 7 colours. Light travels
in waves, and waves can have long wavelengths or short wavelengths.
Light waves can be scattered when it collides with particles in the air. The longer the
wavelength, the harder it is to scatter them when it is traveling through the air (or
other media), and the more likely that it will reach our eyes such that we can see
that colour.
Based on the information above, select all statements which are true about sunsets.
1) We can see orange and red during sunsets as the red light has been mostly
scattered into the air.
2) Sunsets are orange and red because red and yellow light is scattered the least
and most of it has reached our eyes.
3) Blue, indigo and violet light is easily scattered due to its small wavelengths.
4) All 7 colours of light are scattered to some degree when they travel through the
air.
A. Options 1 and 4
B. Options 1, 3 and 4
C. Options 2 and 3
D. Options 2, 3 and 4
Answer: D
Red light waves have the longest wavelengths among the 7 colours, and they scatter
the least when they travel through the air and collide with the particles in the air. As
they scatter the least, most of the red and yellow light waves will travel and reach
our eyes. Hence sunsets usually appear orange to us. All 7 colours of light can be
scattered as they are bound to collide with particles when traveling through the air
(which is made up of particles).
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 14
What is a shadow?
A. A shadow is an area where there is a relative absence of light.
B. A shadow is a black coloured area.
C. A shadow is an area where light is reflected.
D. A shadow is an area where light has been absorbed.
Answer: A
A shadow forms when an object is blocking the light source as it is placed in
front of the light source. It is not a black coloured area, and there is no light
in that area hence it is dark. Light is not reflected in a shadow, it is also not
absorbed (by the surface).
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 15
Mr Joaquim is testing out 4 different strings of equal diameter he has purchased to
find out which is the most suitable to be used as a fishing line.
He set up the following experiment.
For each type of string he cut a 30 cm piece and tied it around a hook which has
been securely fastened to the edge of a table. He continued to add 1 kg weights
starting with the lowest weight, 1 kg, until the string snaps.
He recorded the results in the table below. The tick represents the weight category
in which the string snapped.
1 kg 3 kg 5 kg 7 kg 9 kg
String P √
String Q √
String R √
String S √
Which string should Mr Joaquim use as fishing line?
A. String R
B. String S
C. String P
D. String Q
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Vanda 2020, Primary 4 (Grade 4) Contest
Answer: B
String S only broke when a 9 kg weight was added to it. It was able to withstand the
most weight before breaking. Therefore, it is the strongest and should be used as
fishing line. A large amount of force is exerted during fishing when capturing the
fish, hence a strong material is required.
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 16
Which of the following organs are in use when we are asleep?
1) Kidneys
2) Lungs
3) Spinal Cord
4) Heart
A. Options 1 and 2
B. Options 1, 2, 3 and 4
C. Options 2 and 4
D. Options 3 and 4
Answer: B
When the body is asleep, we continue to breathe to obtain oxygen and remove
carbon dioxide, the respiratory system is still in use continuously. The circulatory
system is always active as the heart pumps 24/7. Our central nervous system
includes our brain, which controls breathing, dreams etc. It is also in use when you
are asleep—processing information.
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 17
Sam is investigating the amount of digested food present in each part of the
digestive system. He plotted a graph from the data he obtained.
Which part of the digestive system does part H represent?
A. Large intestine
B. Gullet
C. Mouth
D. Small intestine
Answer: A
In the large intestine, digested food has already been mostly absorbed into the
bloodstream (ignoring negligible amounts) when it was in the small intestine, the
amount of digested food in this area is zero. Both the mouth and gullet have a small
amount of digested food as there are enzymes in saliva which digests some of the
food we eat. It cannot be the small intestine as the small intestine is the site where
digestion is completed, it should have the greatest amount of digested fo
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 18
The picture below shows a polar bear.
The polar bear has translucent fur which looks white in the snow. However, it has
black skin underneath this cream coloured fur. Polar bears live in the arctic region,
withstanding sub-zero temperatures.
How does the layer of black skin help the polar bear to survive in the artic climate?
A. It helps the polar bear to lose heat quickly as the colour black is a poor
absorber of heat, so that it can keep itself warm.
B. It helps the polar bear to camouflage against the snow when it is hunting for
seals.
C. It protects the polar bear from getting skin diseases, with its prolonged
exposure to the ocean water.
D. It helps the polar bear to gain more heat from the sun’s rays as the colour
black is a good absorber of heat, so that it can keep itself warm.
Answer: D
Black is a good absorber of heat, which means that the polar bear will be able to
gain sufficient or abundant heat from the sun’s rays and keep that heat to make
sure it stays warm in a sub-zero temperature environment.
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 19 and 20 are related.
Question 19
Elephants have large ears which help them to maintain and regulate body
temperature. On hotter days, they may use their ears as fans to move the air over
the rest of their body. The flapping of the ears also cools the blood that circulates
through it, lowering the body temperature. Elephants may also spray water on its
ears to speed up the cooling down of its body temperature.
Which is the correct movement of heat between the elephant’s body and the
environment when the elephant sprays water on its ears?
A. Circulatory system→ elephant’s ears→ surrounding air→ water→ elephant’s
body
B. Water→ elephant’s ears→ elephant’s body→ circulatory system→
surrounding air
C. Elephant’s body→ circulatory system→ elephant’s ears→water→surrounding
air
D. Surrounding air→elephant’s ears→ circulatory system→ elephant’s
body→water
Answer: C
The heat should originate from the elephant’s body as the body produces heat when
it respires. It also gains heat under the sun. When the body temperature is above its
usual temperature, the extra heat has to be lost to maintain an optimal environment
for the bodily processes to function. Heat is lost outwards towards the surrounding
air. The water facilitates heat loss as it evaporates. Heat moves from the body, into
the bloodstream, and to the ears, eventually being lost through the water into the
surrounding air.
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Vanda 2020, Primary 4 (Grade 4) Contest
Question 20
The ears of an African elephant (left) are significantly larger than those of an Asian
elephant (right). Why is this so?
A. The African elephant has a larger head and the larger ears help to balance
the head region of the elephant.
B. The African elephant has more predators in the wild and thus has larger ears
to scare away its predators.
C. The African elephant lives in the African continent which has a hotter climate
than the habitat of the Asian elephant and the larger surface area aids in
efficient heat loss.
D. The African elephant has a higher body temperature than the Asian elephant
and has to lose more heat to keep the body cool.
Answer: C
The climate in the African continent is hotter and sunnier, with higher temperatures.
This means there is a greater need to keep the body cool, and regulation of body
heat is crucial. To aid in this process, the larger areas have a greater surface area
which allows more heat to be lost quickly to cool the body down.
END OF PAPER
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