Revision for SA1 (Set 1) - Booklet A

Qn 1 ( 2) Number of seeds

Qn 2 (4) Spiny Anteater lays eggs
(ref : http://www.americazoo.com/goto/index/mammals/1.htm)

Qn 3 (1)

Concept : conductors of heat
- from the graph, at mid-time (draw a line upward from midtime - x-axis crossing the two line graphs), the temperature of water at A is higher than the temperature of water at B.
Hence we can say that the heat is not lost so quickly in beaker A. The material of Beaker A must be a poorer conductor of heat -> in the option, styroforam is the one that is the poorest in conducting heat.


Qn 4 (4)

Qn 5 (3)
Concept : Gravitational potential energy - The higher the object is from the ground, the higher gravitational potential energy it has.

- From the options, look for the one which is highest from the ground.

Qn 6 (3)


Qn 7 (2)

At A- elastic potential energy
At B - kinetic energy(moving) and gravitational potential energy (above the ground)
At C - similar to B


Qn 8 (4)

Battery - chemical potential energy
Pendulum held at an angle - hanging in the air above the ground (potential energy)
A wound-up toy car - potential energy
A car moving down a ramp - Kinetic energy (moving) and gravitational potential energy (still above the ground)

Qn 9 (1)


Qn 10 (2)

Concept : Effects of force
1) changes the direction of a moving object
2) changes the speed of a moving object (faster or slower)
3) makes a moving object stop
4) makes a stationary object move
5) change the shape of an object

In this case, Meimei smashed with a lot of force, the above works except (3) and (5).


Qn 11 (2)

Qn 12 (3)

Qn 13 (3)

Qn 14 (2)

Qn 15 (4)

Qn 16 (1)
Concept - pond community : classification of plants - totally submerged, partially submerged and on the surface.
Group A - partially submerged
Group B - microorganism
Group C - totally submerged
Group D - floating on the surface.

-> Arrowhead - partially submerged plant

Qn 17 (2)

Concept : Food Chain and effects of introduction of prey or predator.
When a predator is introduced, the prey will reduce in population.
When a prey is introduced, the predator will increase in population.

In this question, when Z was introduced in Wk 2 :
- Population Y increase - possible reasons :
i) more food for Y - Z is a prey of Y Option 4 - wrong
or ii) Z has eaten up X which could be eating Y - X is a predator of Y Option 1 - wrong

- Population X decrease - possible reasons :
i) Z has eaten up X - Z is a predator of X Option 2- correct

Qn 18 ( 4) we have done this qn before

Qn 19 (3)
Concept : food chain and food web - Fish can eat the mosquito when it is at the larva stage (still in the water).

When the mosquitoes are at the larvae stage, they will be low in population as they are eaten by the fish. Hence the population should not be increasing as they are eaten at that stage. ( option 1, 2 and 3 shows that it is increasing over time)


Qn 20 (2)

Concept : factors that affect the survival of animals
- when the pond is completely covered by water hyacinth, there will be less chance for the oxygen in the air to dissolved into the pond water.

- there are no submerged plants to provide dissolved oxygen and food for the tadpoles.

- Sunlight has no effect for the tadpole in terms of food making. althought sunlight helps to heat up the water, but the carbon dioxide given out by tadpole can help to trap the heat in the water to keep the tadpole warm.


Qn 21 (3)
Negative effects (effects that are no good)

Qn 22 (4)
Factors affecting survival:

In this case, the variable that is changed is the temperature of the surrounding. Hence the aim of the experiment is to see how temperature affects the response of the fruitflies.

Qn 23 (2)
The amount of gases given out by the decomposer is carbon dioxide.


Qn 24 (3)

The first food consumer in every food chain can be a carnivore too.

Qn 25 (4)

Qn 26 (2)

Qn 27 (3)
Caterpillar does not eat rotting log but it eats leaves.

Qn 28 (3) Simple machines (not tested in sa1)

Qn 29 (4) Simple machines (not tested in sa1)

Qn 30 (3) Simple machines (not tested in sa1)