Q&A - PSLE Science

[hashroop]

Nebbermind:

Are the above 2 PSLE qns? Did revision with my boy last yr and have not come across such qns.


Or r these taken from some GEP science qn ppr?

At least mine is. My DS2 sat for Mavis Prelim exams yesterday and one of the question was on the developement of human foetus.

[Kloggy]

Nebbermind:

Are the above 2 PSLE qns? Did revision with my boy last yr and have not come across such qns.


Or r these taken from some GEP science qn ppr?

Yes, duckweed question from River Valley, 2010, Prelims.

[P5G]

Please help.


16. The table below shows the number oif organisms in a habitat.

Organism | Number of organisms
--------------------------------------
Ixora |2
Mynahs | 3
Slugs | 7
Butterflies | 11
Snails | 9
Caterpillars | 7

How many populations of animals are there altogether?

(1) 39
(2) 37
(3) 5
(4) 4

Given answer: (4)

Should the correct answer be (3)?

TIA.

[starlight1968sg]

Kloggy:

Hi, can someone help with the following:


An experiment was carried out by placing duckweeds in two beakers with 500ml of water each. 10 ml of bleach was added to one of the beakers. Write an hypothesis for the experiment.

The answer provided was that the duckweed will grow better in the water with bleach added. But why ?

Thanks.

What? add bleach and duckweed will grow better ??? :yikes:

[Sun_2010]

P5G:

Please help.


16. The table below shows the number oif organisms in a habitat.

Organism | Number of organisms
--------------------------------------
Ixora |2
Mynahs | 3
Slugs | 7
Butterflies | 11
Snails | 9
Caterpillars | 7

How many populations of animals are there altogether?

(1) 39
(2) 37
(3) 5
(4) 4

Given answer: (4)

Should the correct answer be (3)?

TIA.

Given answer is correct

Ixora - flower not animal
1. Mynahs
2. Slugs
3. Butterflies and Caterpillars - they are the same population
4. Snails

[benleetube]

Hi everyone. I need help for a question:


Why do fish stalls use small pieces of ice to store/display the fish instead of using big pieces of ice?

Thanks in advance.

[P5G]

13. A ball is bounced on the ground as shown below.


See picture
http://www.orlesson.org/orp/10Sc/2010-P6-Sc-SA1-NanHua.pdf

Which of the following statements about the ball above are true?

A: The kinetic energy is zero at Point X.
B: The kinetic energy is the highest at Point Z.
The potential energy is the highest at Point X.
The ball has both potential and kinetic energy at Poiint Y.

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

Given answer (4).

Should the correct answer be (1).

TIA.

[Nebbermind]

starlight1968sg:

What? add bleach and duckweed will grow better ??? :yikes:

out of curiosity I search and found that there r experiment on how 'sterilized' duckweed will affect its growth/production. but is this topic covered in pr sch syllabus?

[mother777]

benleetube:

Hi everyone. I need help for a question:


Why do fish stalls use small pieces of ice to store/display the fish instead of using big pieces of ice?

Thanks in advance.

Hi,

I think the reason for using small pieces of ice to store/display fish instead of using big pieces of ice is mainly to increase the surface area of contact.

Many small pieces of ice will have a larger surface area of contact with the fish compared to 1 big piece of ice. Larger the surface area, the better chilling affect on the fish making the fish stay fresh for a longer period of time.

Hope this is correct :scratchhead:

[Nebbermind]

P5G:

13. A ball is bounced on the ground as shown below.


See picture
http://www.orlesson.org/orp/10Sc/2010-P6-Sc-SA1-NanHua.pdf

Which of the following statements about the ball above are true?

A: The kinetic energy is zero at Point X.
B: The kinetic energy is the highest at Point Z.
The potential energy is the highest at Point X.
The ball has both potential and kinetic energy at Poiint Y.

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

Given answer (4).

Should the correct answer be (1).

TIA.

I think the only doubt is (B) but if only comparing the 3 positions, then (B) is true.