Q&A - PSLE Science

[atutor2001]

wkong:

Hi atutor,

Your kids are so cute.. barred you from seeing teachers. My DS barred me from asking teachers any questions during P6 Dialogue session as well as during Science workshop too.

Of course, during the Science workshop, I see parents argue the answer with Science teacher, but.. winner is always (you know lah).

Hi wkong

So happy to find someone in the same boat and I am not alone. :celebrate:

[Flipper123]

Could someone explain to me why when germination,seeds need warmth.Does this have anything related to winter? :?

[atutor2001]

Flipper123:

Could someone explain to me why when germination,seeds need warmth.Does this have anything related to winter? :?

Last time, if my kid asked me this question, my answer will be \"ask god tonight when you are sleeping\" :lol:

I also don't know the answer but can only guess using logical thinking that energy (heat/warmth) is usually needed to start or speed up most chemical reactions. Germination in a way is a form of chemical reaction happening inside the cells of the seed.

I stand corrected. Maybe you can google for the answer and teach us. OK?

[ADoc]

atutor2001:

Flipper123:

Could someone explain to me why when germination,seeds need warmth.Does this have anything related to winter? :?

Last time, if my kid asked me this question, my answer will be \"ask god tonight when you are sleeping\" :lol:

I also don't know the answer but can only guess using logical thinking that energy (heat/warmth) is usually needed to start or speed up most chemical reactions. Germination in a way is a form of chemical reaction happening inside the cells of the seed.

I stand corrected. Maybe you can google for the answer and teach us. OK?

Haha! You are humorous! And yes God definitely has all the answers! if only I...

...\"stand corrected\"? echoing the father of someone...haha!

Anyway don't be so bad lah...let's try to answer his/her query.

[ADoc]

Flipper123:

Could someone explain to me why when germination,seeds need warmth.Does this have anything related to winter? :?

hi flipper!
Germination has to do with cellular metabolism as what atutor has pointed out. And the conditions (such as air, water, warmth & even light for some types of plants) have to be \"just right\" in order to ignite this metabolic process. [by the way, pls ignore light as primary science syllabus does not include light for germination]

Think of a (embryonic) seed (which means it has the potential to grow as opposed to a \"dead\" or empty seed which will not grow even if the conditions are favorable) as a super smart hibernating machine. And think of the KEY to this machine as the right amount of air (oxygen), water, & \"warmth\". Under suitable conditions, you will be able to unlock this machine with this key. In other words, the seed will \"decide\" to come out of its hibernation by activating its metabolic process.

Warmth is one of the conditions for activating this metabolic process.

[This part not required in PSLE syllabus]
Do understand that warmth is relative, and to different species of seeds warmth can be anything from above or below room temperature (during each of the four seasons) or even below zero deg.

I could have a body temperature of say 30 deg, so anything above 30 will be considered warmth to me. Similarly, at say 4 deg during winter, anything above 4 deg will be considered warmth. So you see, warmth is relative depending on your reference point.

The more accurate term would be temperature. While some seeds require \"warmth\" at about 20-25 deg maybe, other seeds will only germinate during winter when the temperature is much lower, i.e. even if it's 20-25 deg ( very \"warmth\"), these sort of \"winter\" seeds will not germinate.

hope this makes sense to you..cheers!

[atutor2001]

ADoc:

Haha! You are humorous! And yes God definitely has all the answers! if only I...

...\"stand corrected\"? echoing the father of someone...haha!

Anyway don't be so bad lah...let's try to answer his/her query.

Oops, die liao, I thought no one would notice. :shock:

[meimeitan]

Hi All,


May I know if acid rain pollute sea water? Thanks.

[tianzhu]

meimeitan:

Hi All,


May I know if acid rain pollute sea water? Thanks.

Hi meimeitan

Good Afternoon.

This link may help.
http://library.thinkquest.org/CR0215471/acid_rain.htm

Best wishes

[meimeitan]

Hi TianZhu


I have just gone through the page. Wonderful! Thanks.

[anneshirleygilbert]

Hello. I need help on the topic of water. I read that salt raises the boiling point of water… that a higher temperature is needed for salt water to boil, compared to pure water. Does this mean it takes a longer time to boil salt water? But I observe from cooking that when I add salt to near boiling water, I see a flurry of bubbles in the water almost immediately. Doesn’t this mean salt speeds up the boiling process? I googled for answers… but the variety of views I got is baffling… Pls specify what is PSLE requirement and what is beyond. Thank you.