Sa1 revision 1 2012 answer notes

SA1 REVISION 2 2012
P6 Science

Booklet A

 What to do
 Understand the concept for each
question.
 Underline the key words (question).
 Understand the explanations for each
question.
 Write down the correct answer as
correction.

Question 1 – Answer (2)
 Concept:
 Food web
 Key words (Question)
 removed, most negative impact
 Explanation
 Plants provide food for all living thing, thus they
will have the most negative impact when
removed.

 Concept:
 Food chain
 NOT true
 Explanation
1. True – grass gets energy from Sun to make food
2. True – Mynah gets energy from grasshopper when
the mynah eats the grasshopper
3. True – Energy is passed from one organism to
another in the food chain
4. NOT true – grasshopper does not make food

 Concept:
 Energy forms and Uses
 incorrect
 Explanation
1. Incorrect – energy is not created
2. Correct – solar means light
3. Correct – fossil fuels are organisms that was once
alive
4. Correct – Every organism gets its energy directly or
indrectly from the Sun.

 Concept:
 Friction

 surface, distance travelled, true
 Explanation
 The greater the friction, the lesser the distance
travelled by the box.

 Concept:
 Force

 NOT

 Explanation
 Mass is the amount of matter in an object. Weight
is the force acting on an object due to gravity.

 Concept:
 Photosynthesis

 Successful production of oxygen
 Explanation
 Photosynthesis occurs only in the presence of
light.

 Concept:
 Energy conversion
 Temperature rises considerably at point Z
 Explanation
 Thekinetic energy (when the wire is bending
back and forth) is converted to heat energy.

 Concept:
 Elastic potential energy
5 turns, 10 turns, 15 turns, 20 turns
 Explanation
 The only variable that is changed is the number of
turns.

 Concept:
 Elastic spring force
 Forces acting on the spring
 Explanation
 When you stretch a spring, the spring will exert a
force to try and pull it back to its original length.
 When you compress a spring, the spring will
exert a force to try and push it back to its original
length.

 Concept:
 Volume and weight (matter)
 Equal volume, different weights
 Explanation
 Volume is the amount of space an object takes
up.
 Mass is the amount of matter in an object.

 Therefore, although all 4 cubes have the same
volume, it does not mean they have the same
mass.

 Concept:
 Environment

 Fungi

 Explanation
 Fungi grow in damp and warm places.

 Concept:
 Food web
 Increase,
 mynah population
 Explanation
 When mynah’s population increase, they will eat
more ladybird and spider. Therefore if ladybird
and spider’s population decreases, their prey
(which are aphid and whitefly) will have less
predator and thus increase in number.

 Concept:
 Adaptation

 Function, drip tip
 Explanation
 The drip tip allows raindrops to run off quickly so
that it doesn’t collect on the leaves which will
block the stomata.

 Concept:
 Forces
 Correct forces
 Explanation
 A – gravity acts from a distance and is always a pull
 B – magnetic force acts from a distance and can be a
pull (attraction) or a push (replusion)
 C – friction acts only on contact and opposes the
motion
 D – push only acts when you are touching the object
and it follows the motion

 Concept:
 Elastic potential energy
 Number of turns, distance moved
 Explanation
1 – true, based on graph
 2 – false, 120 turns is needed to move 8 cm
 3 – true, more number of turns, more energy
stored, thus greater distance moved
 4 – true, based on graph

 Concept:
 friction

 Coated with liquid D, lubricating
 Explanation
 The aim of lubricating the moving parts of a
machine is to reduce friction to prevent wear and
tear. Thus, the liquid used must be able to reduce
friction the best.
 The greater the distance moved by the wooden
block, the lesser the friction (or reduce the friction

 Concept:
 Environment – conditions for survival
 Kill, more quickly
 Explanation
 Fair test – only the variable tested must change.
In this case, the variable that is changed is the
type of pesticide. All other variables must be kept
the same.

 Concept:
 Environment – interaction of organisms
 Effectively remove the caterpillars
 Explanation
 BirdQ eats the most caterpillars (as number of
caterpillars left is the least) thus the most effective
to remove the caterpillars.

 Concept:
 Decomposers

 decomposers

 Explanation
 Decomposers (e.g. bacteria) act on dead
organisms and animal waste to break them down
into simpler substances (e.g. nutrients) which is
absorbed by the plants.

 Concept:
 Environment – factors affecting survival
 disease

 Explanation
A disease will cause the drop in the number of
rabbits.

 Concept:
 Environment – factors affecting survival
 Supported by the above data
 Explanation
1. Wrong – The presence of some earthworms indicate
earthworms can still survive in clayey soil.
2. Correct – The number of earthworms in garden soil
is the greatest.
3. Wrong – there is not much moisture in sand and
clayey soil.
4. Wrong – Since the numbers are all different, the
earthworms do not thrive equally well.

 Concept:
 Matter – good conductor of heat and electricity
 Good conductor, heat, electricity
 Explanation
1. Book is a poor conductor of heat and electricity
2. Iron nail and key are made of metal which are good
conductors of heat and electricity
3. Plastic comb is a poor conductor of heat and
electricity
4. Rubber phone cover is a poor conductor of heat and
electricity

 Concept:
 Water - Condensation
 Cold room, tiny droplets
 Explanation
 Warm water vapour from the surrounding air
touches the cooler surface of the window, loses
heat and changes to water droplets.

 Concept:
 Cells

 Does not belong
 Explanation
 Option 1 – 3 are animal cells, option 4 is a plant
cell since only plant cells have cell wall.

 Concept:
 Materials

 Different materials
 Explanation
 Foam is the worst conductor of heat thus heat
from the cup will take the longest to escape to the
surrounding air, thus will contain the highest water
temperature after 1 hour.

 Concept:
 Human digestive system
 Produce digestive juices
 Explanation
 Mouth, stomach and small intestines contains
digestive juices. Large intestines only absorbs
water, so no digestion takes place there.

 Concept:
 Plant parts
 Plant parts
 Explanation
 They are all stems that store food.

 Concept:
 Electricity

 Diagram 1, only bulb B lit up
 Diagram 2, bulb A lit up but bulb B did not

 Explanation
 Sinceonly the right bulb lights up, Y is the
conductor of electricity but X is not.

 Concept:
 Seed dispersal
 hooks

 Explanation
 Seeds / fruits with hooks will be dispersed by
clinging onto the fur of animals.

 Concept:
 Reproduction

 Reproduction, plants, animals
 Explanation
1. Not true for animals
2. True for both
3. Not true for both
4. Animals does not have pollen grains

Booklet B

 What to do
 Understand the concept for each
question.
 Underline the key words (question).
 Write down the key words (answer) for
each question (that you did not get full
marks) as correction.

Question 31
 Key Concept:
 Living things need air, food and water to survive.
 Key Words or Phrases
Question Answer
a) Name, gas Oxygen
b) Explain, Plants give out oxygen
dependent during photosynthesis
c) Explain, dark room Lizard die because no
oxygen

Question 32
 Key Concept:
 Living things need air, food and water to survive.
Question Answer
a) Explain, survive Snails give carbon dioxide for
plants to make food
b) Explain, survive Plants give out oxygen during
photosynthesis needed by
snails
c) Explain, amount Less oxygen as more snails

Question 33
 Key Concept:
 Photosynthesis requires sunlight, water and
carbon dioxide.

Question Answer
a) True, False, NPTT F, F, NPTT, NPTT
b) Suggest why, Plants cannot receive
unfavourable enough sunlight to make
food
No sunlight  Wrong concept as sheltered areas will still
get sunlight. It’s just not enough.

Question 34
 Key Concept:
 Different factors affect the local environment
Question Answer
a) Explain, Most loss Q. Strong wind, evaporate
in mass faster (Q does not have most exposed
surface area so large exposed surface area is
correct but not larger/largest exposed surface
area)

b) What, P dry faster Bigger (comparison) surfaced area
c) Suggest, dry Sunny place / less humid
faster without

Question 35
 Key Concept:
 Adaptations serve to enhance survival
Question Answer
a) Explain, change Hide / blend with
colour, survive surroundings to escape
predators
b) Which feature, Large ears. Large surface
explain area to allow animal to cool
down

Question 36
 Key Concept:
A force can move a stationary object
Question Answer
a) State, change in GPE  KE
energy
b) State, which balls 3, 4, 5
c) Ball 1 heavier, Ball 5 – move further /
what change higher
http://www.walter-fendt.de/ph14e/ncradle.htm

Question 37
 Key Concept:
 Friction is an opposing force relative to the motion
of objects.
 Test is on the size of wheel

Question Answer
a) Describe, Same plank
correct (fair
test)
b) List, 2 mistakes Did not change size of wheel
Did not use same number of wooden

Question 38
 Key Concept:
 Forces
causes the extension of springs
 Compare mass of …

Question Answer
a) List, 2 Same spring / Same scale pan
variables
b) What, Length of spring / Extension of
measure, the spring
greatest mass

Question 39
 Key Concept:
 Environmental conditions affects the habitat of
decomposers
Question Answer
a) What, min temp 25oC
b) State, conclusion The lower the temperature, the
slower the rate of decomposition
c) Suggest, one way, Cold place / refrigerator
Explain slow down the rate of
decomposition.

Question 40
 Key Concept:
 Plants,
animals, fungi and microorganism forms
the 4 major groups in classification of living things
.
 Key Question Phrases
Words or Answer
a) Explain, cake P not enough water / little water /
moisture
b) How, mould get break down the cake into simpler
food substances and absorb nutrients
c) Another similarity, respond to changes OR
fungi, plants grow and reproduce OR
cannot move freely from place to

Question 41
 Key Concept:
 Use of magnets to separate magnetic objects
Question Answer
a) Suggest, Use magnet to attract steel ball
separate bearings
b) Suggest, Pour contents slowly into the
another, bucket of water. Cork pieces
separate will float

Question 42
 Key Concept:
 Temperature is a measurement of how hot or cold
an object is; heat is a form of energy.
 Key Words or Phrases

Question Answer
a) Arrange S,Q,R,P
b) Explain, longer Greater volume of water at
100oC

Question 43
 Key Concept:
 Anelectrical system comprises of various
components.
Question Answer
a) Group Parallel – B, D, E
Series – A, C, F

Question 44
 Key Concept:
 Plants
reproduce to ensure the suvival of their
own kind.
Question Answer
a) How many 5 months
months
b) Draw, Red
Clover

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Sa1 revision 1 2012 answer notes