Q&A - PSLE Science

[Sun_2010]

P5G:

Please help.



http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-Nanyang.pdf

Q40 a) Which two mirrors can be removed so that no images of the ball are seen by the eye?


Worksheet answer: A and C.


My answer: B and C (or A and B).


Please advise which is correct?


TIA.

Dig deeper into these pages u will find a very clear explanation with diagram in this topic

[Sun_2010]

P5G:

Please help.



http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-MGS.pdf


Q24.

Ericia carried out an experiment to compare the amount of water in 4 different vegetables. Firstly, she weighed the vegetables. Then she placed the vegetables out in the sun for a few days to dry them before weighing them again. She then recorded her results in the table below.

Please refer to the table in the worksheet.


Based on the above results, which of the following statement(s) is/are true of her experiment?

A. W has less water than Y.

B. X has as much water as W.

C. Z has the least amount of waater.

D. y has the greatest amount of water.


(1) A only

(2) B and C only

(3) A and D only

(4) A, B, C and D


Worksheet answer is (3).

My answer is (4).

Please advise which is correct.

TIA.

I think u have given the wrong link.

[tianzhu]

P5G:

Please help.



http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-Nanyang.pdf

Q1. Based only on the above diagram, what can be inferred from the fruit of plant Z?

A. Plant Z porduces flowers.

B. The fruit of plant Z is dispersed by wind.

C. The flesh of the fruit of plant Z is juicy and tasty.

D. The fibrous husk helps the fruit of plant Z to float.


(1) D only

(2) A and D only

(3) A, C and D only

(4) A, B, C and D only


My answer is (1) but the worksheet answer is (2). Which is correct?

TIA.

Hi P5G

Under the topic on reproduction in plants, students learned that after fertilisation, the ovary in flowering plant gradually develops into a fruit. The ovules inside the ovary develop into seeds.

Based on this information, one may infer that plant Z produces flower.

Therefore, option (2) is a logical answer.

Best wishes

[tianzhu]

P5G:

Please help.



http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-Nanyang.pdf

Q44 d) Explain whether it is a fair experiment to compare how well material P and Q conduct heat when Section X is longer than Section Y.

Worksheet answer: It is a fair experiment as we can check the distance of the nails A and B from the heat source is the same.

My answer: No. With a longer Section X, more heat will be lost at Section X and nail A will receive less heat than nail B.

Please advise which is correct?

TIA.

Hi P5G

Yes, it’s a fair test as the distances of the nails are the same from the heat source.

In primary science, students learned that when two objects are touching each other, heat from the hotter object flows to the colder object by conduction. Some materials conduct heat better than others and they are known as good conductors of heat.

How heat energy is transferred from the hotter end of the object to the cooler end is through a process of increased vibrations and collisions of particles. I think this is not in PSLE science syllabus. You may find out more when you are in secondary school.

For PSLE science, remember that given two objects of different materials and similar cross sectional area or thickness, for the same distance, heat will travel faster in the object which is a better conductor of heat.

Best wishes

[tianzhu]

P5G:

Please help.



http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-Nanyang.pdf

Q40 a) Which two mirrors can be removed so that no images of the ball are seen by the eye?


Worksheet answer: A and C.


My answer: B and C (or A and B).


Please advise which is correct?


TIA.

Hi P5G

Based on the question, one answer is to remove A and C.

I think you can also remove B and C, A and D and A and B.

Best wishes

[P5G]

Sun_2010:

P5G:

Please help.



http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-MGS.pdf


Q24.

Ericia carried out an experiment to compare the amount of water in 4 different vegetables. Firstly, she weighed the vegetables. Then she placed the vegetables out in the sun for a few days to dry them before weighing them again. She then recorded her results in the table below.

Please refer to the table in the worksheet.


Based on the above results, which of the following statement(s) is/are true of her experiment?

A. W has less water than Y.

B. X has as much water as W.

C. Z has the least amount of waater.

D. y has the greatest amount of water.


(1) A only

(2) B and C only

(3) A and D only

(4) A, B, C and D


Worksheet answer is (3).

My answer is (4).

Please advise which is correct.

TIA.

I think u have given the wrong link.

Thanks Mr Sun_2010.

I am sorry that the school should be CHIJ St Nicholas SA2.

The correct link is as follows:

http://www.orlesson.org/orp/09Sc/2009-Sc-SA2-StNic.pdf

Worksheet answer is (1).

My answer is (4).

Please advise which is correct.


TIA.

[teachingmum]

Came across this question and is kinda stumped…


An experiment is conducted. 10 seeds were geminated in the dark and 10 similar seeds were germinated in the light. Readings of height, size of leaves were recorded for a week.

Reading A shows short stem but big leaves
Reading B shows long stem but small leaves.

The question asks which set of reading belongs to the seeds germinated in the dark and what the colour of the leaves is…

The problem I have is:
(1) seeds do not need light for germination. In fact, for hydroponic, the seeds for germination are put in a black garbage bag.
(2) germination may take as long as a week or even longer

So, what should the answer be?

Should I assume since there are leaves, photosynthesis shd be happening and hence light will be an impt factor? However, if the true leaves have yet appeared, then REading B cannot be for the seeds germinated in the dark right?

[atutor2001]

teachingmum:

Came across this question and is kinda stumped...


An experiment is conducted. 10 seeds were geminated in the dark and 10 similar seeds were germinated in the light. Readings of height, size of leaves were recorded for a week.

Reading A shows short stem but big leaves
Reading B shows long stem but small leaves.

The question asks which set of reading belongs to the seeds germinated in the dark and what the colour of the leaves is...

The problem I have is:
(1) seeds do not need light for germination. In fact, for hydroponic, the seeds for germination are put in a black garbage bag.
(2) germination may take as long as a week or even longer

So, what should the answer be?

Should I assume since there are leaves, photosynthesis shd be happening and hence light will be an impt factor? However, if the true leaves have yet appeared, then REading B cannot be for the seeds germinated in the dark right?

Hi, don't be upset. The trick in this question lies in the word highlighted in bold \"Readings of height, size of leaves were recorded for a week\".

For normal seeds (beans as covered in Pr sch), germination usually will have been completed by the end of the week. Therefore, the question is actually testing on \"time sense\" and knowledge on \"light is needed for photosynthesis\".

I used to teach my kids to focus on the \"time frame\" given in the question and not be tricked by the keyword \"germination\". Maybe you can try doing the same.

[teachingmum]

Hi atutor,


Thanks. Not so much of upset, but confused by the vagueness or 'trickiness' of the question.

[MOE Hater]

According to what I am taught in learning lab, reading B should be for the plants growing in the dark.