Q&A - P3 Science

[Tang]

elkniwt:

watmekiasu:

My answer would be 3 (B and D). Plants and fungus can move on their own, albeit very slowly. Take for eg how a plant grows towards an opening with light. My dd says that the action of the venus flytrap and pitcher plant in catching insects are also eg of movements (I tot that was respond to changes, anyone can confirm this ??).

Thanks for the clarification. Phew! At least get this concept clear b4 the exam. Looks like I have a lot to learn too.! :oops:

Closing to trap the insects is response to changes.

But after digesting the insects, the pitcher flower opens again on its own, i.e. movement on its own.

[watmekiasu]

Tang:

Closing to trap the insects is response to changes.

But after digesting the insects, the pitcher flower opens again on its own, i.e. movement on its own.

Tks.

[tianzhu]

elkniwt:

More help, please!!.


Qn 24 for Henry Park P3 SA2 paper
http://www.wendykoh.com/08/primary3-hpsa2-science.pdf

Ans in the ans key is 4. I didn't know that placing magnet in water will make it lose its magnetism. :? I thought ans is 2. :?:

Hi

In P3 Science, students learn that a magnet loses its strength when it is hammered or dropped from a height. Heating a magnet can also cause it to lose its magnetism.

Please refer to this link for more information.
http://www.science.edu.sg/ssc/detailed.jsp?artid=2762&type=6&root=5&parent=5&cat=57

Option (2) is a logical answer.

Best wishes

[elkniwt]

tianzhu:

Hi

In P3 Science, students learn that a magnet loses its strength when it is hammered or dropped from a height. Heating a magnet can also cause it to lose its magnetism.

Please refer to this link for more information.
http://www.science.edu.sg/ssc/detailed.jsp?artid=2762&type=6&root=5&parent=5&cat=57

Option (2) is a logical answer.

Best wishes

Thanks! Tianzhu.

[tianzhu]

elkniwt:

There's this question on an experiment. It shows a magnet attracting many nails. Then after the magnet is heated, it shows the number of nails attracted by the magnet is greatly decreased. And the qn asked : What does the experiment above show about magnets?

My dd's ans is \"If you heat a magnet, it will lose its magnetism.\" And it was marked wrong. Her teacher's ans is \"A magnet loses its magnetism when heated.\" What's the difference?? :?

Hi
The teacher’s answer is correct.

What does the experiment above show about magnets?

This question asked for the conclusion of the experiment not the prediction or hypothesis before carrying out the experiment.

Best wishes

[tutormum]

elkniwt:

Hi,


Qn 4 for Henry Park P3 SA2 paper
http://www.wendykoh.com/08/primary3-hpsa2-science.pdf

dd is asking how come there is no B only option?
The nearest will be (3) B and D only. But I thought they cannot move on their own. :?

We got to get these concepts clear:
1. All living things can move on their own, ie. they do not require an external force to be applied on them to make them move.
2. Animals can move about, ie. from place to place while plants and fungi cannot. Plants and fungi stay in one place. One example of plants moving is when they open and close their leaves.
3. All living things respond to changes and stimuli. Respond to changes means if you are caught in the rain, you run for shelter. Of course, in this case, movement is involved. Plants can't run for shelter when it rains, not because they don't respond but they can't move about.

[rains]

tianzhu:

The teacher’s answer is correct.


What does the experiment above show about magnets?

This question asked for the conclusion of the experiment not the prediction or hypothesis before carrying out the experiment.

Best wishes

At P3, are we really so particular about whether the child is phrasing in a 'prediction mode' or 'conclusion mode'? It'll be scary if it is. The key phrase 'lost its magnetism' is already there. If the teacher really gives such a reason, I must say the teacher is really lame.

[Tang]

tianzhu:

Hi

The teacher’s answer is correct.

What does the experiment above show about magnets?

This question asked for the conclusion of the experiment not the prediction or hypothesis before carrying out the experiment.

Best wishes

I have spoken to my best friend this morning. He suggested that since the magnet still can attract iron nails (but fewer), it is best to retain the keywords 'heated' and 'loses magnetism' and yet to meet the condition given by adding 'some of' as follows:

When heated, the magnet loses some of its magnetism.


With the suggested answer, we are likely not to lose any mark.

[atutor2001]

tianzhu:

Perhaps, the following links will provide useful information on the reproduction and root system of sweet potatoes. The answer given in the WS is correct.

http://www.science.edu.sg/ssc/detailed.jsp?artid=1513&type=6&root=2&parent=2&cat=18

Hi tianzhu

After reading the article that sweet potato plant does not grow from the sweet potato itself, I was surprised because I remembered planting a sweet potato patch from sweet potatoes.

I googled and found most people recommended using sweet potato to produce sweet potato plants. Below is one of the articles to share with you :
[quote]Sweet potatoes are usually grown from slips; small rooted pieces of tuber. You can create your own slips by slicing a sweet potato in half lengthwise and placing it on a bed of damp potting soil. Cover the pieces with a few inches of soil and keep moist and warm. Small roots should develop within a few days, followed by leaves. They are ready to be lifted and planted once they’re about 4 - 8 inches tall. (About 6 weeks.) You can try growing sweet potatoes from the grocery store, but the only way to be certain you have certified disease-free roots is to buy them from a reputable seed supplier.[/quote]Regards

[tianzhu]

Hi atutor2001


Thank you for your sharing. Yes, we can grow sweet potato plant from sweet potato. The article from science net has stated this fact.

Another useful link on the growing sweet potato.
http://www.ehow.com/how_2074676_grow-sweet-potato-plant.html

Best wishes