Q&A - PSLE Science

[youngtay]

hi, Please help



P5 Science from Nanhua SA2 2009

question 4. Nancy prepared a glass container which contained 100 cm3 of air (taken from the surroundings) as shown in the set-up shown below.
(Sorry there is a picture ,but I don’t know how to add link,there is a rubber stopper on top of the glass container)

What is the approximate volume of oxygen present in the container?
(1) 1 cm3
(2) 21 cm3
(3) 78 cm3
(4) 100 cm3

question 16. Which of the following statements about the animal and plant transport systems are true?

A. An animal needs an organ to pump blood to transport materials around the body.
B. No organs are needed by a plant to transport materials around the plant.
C.A plant has only one type of tube to transport materials around the plant.
D.Only oxygen and digested food are transported around the body of an animal.

(1) A only
(2) A and B only
(3) A,B and D only
(4) B, C and D only.


question 28. Tom found 3 objects and wanted to test if they were magnets. He bought a magnet from the school bookshop and placed it next to each of the objects. This is what he observed.

Object A – No reaction
Object B – Repelled
Obejct C – Attracted

Which of the following object (s) is definitely a magnet?

(1) Object B
(2) Object C
(3) Objects A and C
(4) Objects B and C


question 29. Alex conducted a study on animal X and Animal Y. He used a checklist and placed a tick in the appropriate box when he made an observation. The completed checklist is as follows:



Observation Animal X Animal Y

Eggs are laid in water Y Y
There are 4 stages in the life cycle
It has six legs Y


Which of the following could be Animals X and Y?

Animal X Animal Y

1. frog mosquito
2. frog dragonfly
3. mosquito frog
4. dragonfly frog


Please help. TIA

[tianzhu]

Hi youngtay


Please go to page 3,10,15 and 16 of this link to read the questions.
http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-NanHua.pdf

For Q4, in primary science, students learned that air is a mixture of nitrogen, oxygen, carbon dioxide, water vapour and other gases. These gases are present in the air in different amounts.

For a volume of 100ml of air, it’ll have 21ml of oxygen or 21%.
Therefore, the answer is option (2)

For Q16, under the topic on transport system in plants, a student learned that a plant has two kinds of tubes; they are Xylem tubes (water and minerals) and Phloem tubes (food).

In Circulatory System, students learned that besides oxygen and digested food, the blood also transports water, carbon dioxide, nutrients and other waste materials.

Therefore option (C) and (D) are offside.

The heart pumps blood around the body and no organs are needed by plants to transport materials around the plant.

The answer is option (2)

Under the topic on magnets, a primary student learned about magnetic and non magnetic materials. They also learned that magnets can attract or repel one another, like poles repel and unlike poles attract.

Object A is a non magnetic material.
Object B is a magnet. The repulsion is due to unlike poles facing one another.
Object C is a magnetic material. We cannot conclude that it is a magnet unless we carry out the repulsion test.

Therefore, the answer is option (1)

For Q29, I’ll assume that you have knowledge on where the animals lay their eggs or the number of legs they have from reading your books.

Observe the row on life cycle in the observation list, there are no ticks. This means both X and Y do not have four stages in their life cycles.

The dragonfly and frog have three stages in their life cycle, while the mosquito has four.

Therefore, the answer is option (2).

Best wishes

[youngtay]

Mr Tianzhu


Thanks for your explanation.

Best wishes

[tianzhu]

youngtay:

Mr Tianzhu


Thanks for your explanation.

Best wishes

Hi youngtay

You’re welcome.

Please do not be so formal by addressing me as Mr Tianzhu.

If you are a daddy or mummy, just call me tianzhu.If you are a kid, just call me uncle tianzhu.

Just take this forum as a platform where members exchange their views/ideas in a friendly and conducive environment.

Best wishes

[atutor2001]

youngtay:

.....


question 16. Which of the following statements about the animal and plant transport systems are true?

A. An animal needs an organ to pump blood to transport materials around the body.
B. No organs are needed by a plant to transport materials around the plant.
C.A plant has only one type of tube to transport materials around the plant.
D.Only oxygen and digested food are transported around the body of an animal.

(1) A only
(2) A and B only
(3) A,B and D only
(4) B, C and D only.

.....

Option B is also False.

Cells form tissues and a collection of tissues form organ. Organ is not confined to animals. Plants have cells, tissues and therefore organs. Roots and stems are organs of plants and are needed for for transportation of materials.

Therefore the answer is (1) A only

[Nebbermind]

But are they taught that stem and roots are organs? :?

[starlight1968sg]

atutor2001:

youngtay:

.....


question 16. Which of the following statements about the animal and plant transport systems are true?

A. An animal needs an organ to pump blood to transport materials around the body.
B. No organs are needed by a plant to transport materials around the plant.
C.A plant has only one type of tube to transport materials around the plant.
D.Only oxygen and digested food are transported around the body of an animal.

(1) A only
(2) A and B only
(3) A,B and D only
(4) B, C and D only.

.....

Option B is also False.

Cells form tissues and a collection of tissues form organ. Organ is not confined to animals. Plants have cells, tissues and therefore organs. Roots and stems are organs of plants and are needed for for transportation of materials.

Therefore the answer is (1) A only

Animals have a heart to pump blood...
Plants dont have such an organ ie heart.
Plants have 2 types of tubes.
Carbon dioxide and waste materials are transported round the animals too.
Thus ans should be (1)

[atutor2001]

Nebbermind:

But are they taught that stem and roots are organs? :?

Some schools yes, most schools no. However, they should have covered knowledge on what makes an organ. Therefore, with proper application of science definition, they can argue that students can infer that plants also have organs.

During my time, the common question is \"which is the largest organ - skin\". At the end of it, it is important to do as many science questions as possible and take note of such questions. (I used to do that for my kids which is why I can still remember this question)

[WS1234567]

i think it’s good to know that plants have organs too but fret not parents. Kids do not need to need to know this fact for PSLE. Check out the syllabus and you’ll know what I mean.


For PSLE, kids only need to know the parts of the human body and those in the plants that help to transport stuff aound the organism. Sometimes, school ask questions that are out of syllabus and they are unaware.

I prefer to emphasise on the process skills and answering skills to ensure good results. I know because I go for Science PSLE marking exercise. Year in year out, kids don’t do well for the same reasons.

[atutor2001]

WS1234567:

.....

I prefer to emphasise on ..... and answering skills to ensure good results...........

Hi WS1234567

This question has been bugging me for years. It goes like this :

An experiment was conducted by pouring equal amount of water into 3 identical funnels containing equal amount of 3 different types of soil. The time taken for 20 cu cm to flow through was recorded. What is the aim of the experiment?

Below are possible answers that I have come across. Which one in your opinion is the best or if none, how should the aim be crafted.

1. To find out the the time taken for 20 cu cm of water to flow through each type of soil.
2. To find out the effect of each type of soil on the time taken for 20 cu cm to flow through.
3. To find out how different types of soil will affect the time taken for 20 cu cm of water to flow through.
4. To find out the porosity of each type of soil.
5. To find out which soil is the most porous.
6. To find out which soil retains the most amount of water.
7. To find out which soil would take the longest/shortest time for 20 cu cm of water to flow through.

Thanks