Q&A - PSLE Science

[ruyu]

tianzhu:

ruyu:

ok thanks one more question, does the floating plants and fish interdepend on one another?

Hi ruyu

Good Morning
It’ll be interesting to hear what you think is the answer. Please share your view.

Best wishes

i am not quite sure....

[starlight1968sg]

Yes, the fish can eat the floating plants; the carbon dioxide given out by the fish can be used when the floating plants make food during photosynthesis.

[ruyu]

starlight1968sg:

Yes, the fish can eat the floating plants; the carbon dioxide given out by the fish can be used when the floating plants make food during photosynthesis.

ahh but the stomata is above the water so the roots take in air?

[atutor2001]

ruyu:

ok thanks one more question, does the floating plants and fish interdepend on one another?

The floating plant provides shelter for the fish from predators . The waste from the fish is fertiliser for the plant.

[ruyu]

atutor2001:

ruyu:

ok thanks one more question, does the floating plants and fish interdepend on one another?

The floating plant provides shelter for the fish from predators . The waste from the fish is fertiliser for the plant.

the roots of the plant are in the water and not on the soil

[fudgemum]

Hi,


This is Pei Chun 2009 SA1 question.

A plant with a woody stem is smeared with a layer of oil on both surfaces of the leaves.
Will the plant be able to carry out Photosynthesis ?.
Will the plant be able to carry out Respiration ?.

Answer given in the worksheet is
cannot photosynthesis and can carry out respiration. Is it correct ?.
TIA

[tianzhu]

Hi ruyu


Floating plants offer shade for fish and protection from predators. Predators cannot see fish when they are under the pads. The pads also offer shade from the hot sun. As the name suggests, floating plants float on the surface of water and take in nutrients from the water, which is partly enriched by the fish’s waste.

I think at PSLE, it is good enough stop here. From going through with my boy on past years papers last year, I’ve yet to come across question on interdependence between floating plants and fish.

One common question is interdependence between animals and plants in a terrarium. If I remember correctly, the question usually touches on submerged plants such as hydrilla.

Best wishes

[tianzhu]

Hi


I think you are referring to Q6.Please follow this link.
http://www.orlesson.org/orp/09Sc/2009-P6-Science-SA1-PeiChun.pdf

This is not an easy paper.

The coating of oil on the leaves prevents gaseous exchanges, therefore preventing photosynthesis.
Plants can also respire through stems and roots. Option (4) is correct.

Best wishes

[fudgemum]

Hi tianzhu,


Thanks for the answer.

One more clarification.

http://www.orlesson.org/orp/09Sc/2009-P6-Science-CA1-PeiHwa.pdf
Question No 44.

Is the answer correct ?.

My child says object A is a magnet because the magnet (in the picture) is attracted (moved) towards object A.
If object A is a magnetic material the magnet will remain in its own position and only object A is moved towards the magnet. There was a question similar to this in P4 and it was marked wrong. Cannot remember properly.

TIA.

[Sun_2010]

fudgemum:

Hi tianzhu,


Thanks for the answer.

One more clarification.

http://www.orlesson.org/orp/09Sc/2009-P6-Science-CA1-PeiHwa.pdf
Question No 44.

Is the answer correct ?.

My child says object A is a magnet because the magnet (in the picture) is attracted (moved) towards object A.
If object A is a magnetic material the magnet will remain in its own position and only object A is moved towards the magnet. There was a question similar to this in P4 and it was marked wrong. Cannot remember properly.

TIA.

Hi fudgemum,
nice point. But I think that is true only if Magnet is heavier than Object A. Consider an iron bar and a small magnet. the magnet will move and get stuck to the iron rod, wont it?

Tianzhu, your expert comment please