Q&A - P3 Science

[Puffer]

tianzhu:

Puffer:

A question on Life Cycle:


There are 3 and 4 stages in a life cycle. True or False?

Hi Puffer,
Good Morning

Just out of curiosity, where is your question from?

There are 3 and 4 stages in a life cycle. True or False?

Judging from the context of your question, the answer appears to be true.
Yes, there are 3 and 4 stages in a life cycle.

However, if the question is rephrased as There are only 3 and 4 stages in a life cycle, thing gets tricky.

I have an old copy of MC PSLE Science Guide (used for PSLE2009), it states that the life cycle of a cow consists of two stages.

If I can recall correctly, primary science textbooks generally touch on 3 and 4 stages life cycle. I’d suggest you check with her science teacher on the classification of life cycle for mammals that give birth to their young alive.

Best wishes

Hi Tianzhu,

ok, the actual question is from DS' SA1 2009 paper:

Qn: Which of the following statements about a cycle is/are true?

A: A cycle is a pattern that goes in a circular manner.
B: A cycle is a pattern that repeats itself continuously.
A cycle stops when the adult passes away.
A cycle has only three or four stages.

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

DS' answer to the above is (4), but marked as wrong (teacher's answer is (3).

Initially, I thought this qn is about 'Life Cycle', but now I think 'cycle' here could mean Day-Night Cycle which is a 2-stage cycle. So, I would still stick to (4) as correct answer. What do you think?

I was surprised DS came back telling me that teacher told class there is no more 2-stage life cycle.

[tianzhu]

Hi puffer

Good Morning,

In primary science, students learned that a cycle is a pattern that repeats itself continuously. The topics under this theme are life cycles of animals and plants, matter and water.

In answering this question, much depends on the classification of terms, for example, how to classify the life cycles for mammals giving birth alive. MC PSLE Science Guide states that the mammals such as cow, rabbit, cat, elephant, and dolphin have two stages in their life cycles.

You may want to take a look at this book. In my opinion, this is a very useful book for primary science. Although the book’s title is PSLE Science, it should come in handy for lower levels as well because it is sub divided into various themes from P3 to P6.

The question here is whether we should count the egg stage where the young animal is still inside its mother’s body. I suggest you write to your child’s teacher for confirmation.

We should bear in mind that not only living things have cycles. Cycles also occur in non living things.

As you’ve mentioned, cycle such as day and night consists of two stages. The oxygen and carbon dioxide cycle is another example. There are also plants that reproduce from leaves and stems.

In most MCQ questions, try not to choose an answer choice that contains an extreme word (all, always, none, never, only etc.).Most of the times, they are offside. This is the realities of life. Take for example, a young couple who are deeply in love. They may use words such as You are the only one whom I love, I’ll always love you, I’ll never leave you alone, I’ll always help you to do housework etc. But judging from the many posts in the threads on relationships and divorces, one should know that at times, they are far from the truth.

Now let’s look at your question. I’ll skip option (1) to (3).I think you are not having any problem with these options.

For option (D), focus on the word only------ A cycle has only three or four stages. Is this true? Definitely not, as you have mentioned, there are 2 stages cycles such as day and night. Hence option (D) is offside.

I’d go for option (3) --- A cycle is a pattern that repeats itself continuously.

Best wishes

[elkniwt]

tianzhu:

Hi elkniwt and muffins,

Good Morning,

Looking at this question, it is hard not to miss one word in upper case and bold. Why do you think LEAST might mean from the context of this question? What clues does the setter intend to give?

In this instance, I shall take LEAST to mean the lowest, fewest or smallest in number.

In primary science, students learnt that bread mould grows quicker in dark, wet and warm conditions.

The toaster heats up the bread and removes the moisture from them; therefore it’s not likely to have moulds after three days. Hence option (1) and (3) are offside.
Between option (2) and (4), I’d go for option (2) because the amount of air in the sealed bag is limited.

Before I go off, muffins, I am no expert. I am a victim of circumstances. I am also learning as I answer questions because I’ve to do further reading.

Best wishes

Dear tianzhu and muffins,

Thank you very very much for your help. :thankyou:

This question is indeed tricky.

Thanks again,
elkniwt

[elkniwt]

Need some expert advises here. :?:


Is a wooden ladle or a metal spoon waterproof? I thought metal spoon is waterproof while a wooden ladle is not. Please advise. Thanks.

Btw, I am referring to RGS P4 2009 SA1 Paper Qn 33
http://www.orlesson.org/orp/09Sc/P4-09-Sc-SA1-RGS.pdf

[Tang]

elkniwt:

Need some expert advises here. :?:


Is a wooden ladle or a metal spoon waterproof? I thought metal spoon is waterproof while a wooden ladle is not. Please advise. Thanks.

Btw, I am referring to RGS P4 2009 SA1 Paper Qn 33
http://www.orlesson.org/orp/09Sc/P4-09-Sc-SA1-RGS.pdf

Wood is not waterproof. (There are water carrying tubes in it.)

Metal is waterproof.

[jesschan]

Is it possible to find directions in a jungle if you only have an unlabelled magnet and a string?

[Tang]

jesschan:

Is it possible to find directions in a jungle if you only have an unlabelled magnet and a string?

I think so. Look at the direction of the shadow and the magnet.

[elkniwt]

Tang:

Wood is not waterproof. (There are water carrying tubes in it.)

Metal is waterproof.

Thank you, Tang!! :lol: So, the answer key is wrong.

[tianzhu]

Hi


There is an advertisement on cookware by Robinsons in ST today. I’ve a stainless steel pan similar to the one in this link.
http://www.wmf.com/pans/stainless-steel-pans_82511326.html?sid=7DC33254-E9A5-4B18-ADEC-733CE7E1DF51

The handle is also made of stainless steel. In primary science, students are usually taught that the handles are made of plastic, wood or rubber so that it’ll not be too hot to hold.

My boy asked me why and we had quite a few interesting moments then.

Best wishes

[Sun_2010]

tianzhu:

Hi


There is an advertisement on cookware by Robinsons in ST today. I’ve a stainless steel pan similar to the one in this link.
http://www.wmf.com/pans/stainless-steel-pans_82511326.html?sid=7DC33254-E9A5-4B18-ADEC-733CE7E1DF51

The handle is also made of stainless steel. In primary science, students are usually taught that the handles are made of plastic, wood or rubber so that it’ll not be too hot to hold.

My boy asked me why and we had quite a few interesting moments then.

Best wishes

Good point.
The thing is man made stuff can customised as per need. Dotty wanted to know how come the glass on full length windows is not fragile?
Similarly rubber- can be tuned as per requirement.
So generalizing the properties to applictions can be a bit confusing, At P3/P4, they are OK, but later when they star assocaiting to many of the real life products , it does get a bit confusing...
They have to think what is expected of them, what they have been taught per syllabus , why the exceptions/specialised cannot be taken in before answering.

Like in the example , if there was a question about which material would be suitable for making a handle of a cooking pan, steel would be marked incorrect. For that matter any metal.



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