Pei Hwa Presbyterian Primary

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cg88:

2. Open ended Q39. Fatimah decided to cut away all the leaves on his pot of plant in his garden. What do you think would happen to the pot of plant?

Answer : the plant will die eventually.
Reason: the plant cannot get sunlight and will not be ableto make food, hence it will die.

My son's answer: the leaves will grow back.
Reason: there are still food and nutrients stored in the stem, which will enable the leaves to grow back.

the teacher's explanation: the stem is too thin, therefore not much food in the stem!

This question is quite similar to the Science Practical wooksheet they had done before. But the question was such that the boy continue to cut off the leaves once it grow back, therefore the plant will die once all the food had been used up.

I am still not convince by these answers. Can anyone explain better? :?:

Let me attempt. Your son is quite right. Again, it's very subjective to state that the stem is TOO thin, it's not so for all plants. So in this case, we could explain such that:

Plants need to respire and photosynthesise. If the leaves are cut off, the plant will not survive because the tiny openings (stomata, if they are taught) in which the plant uses for exchanges of gases are mostly removed. Thus, the plant will eventually use up its food and die.

The word 'eventually' is used here because the plant may still survive for a couple of days. The new leaves may not grow fast enough for it to start making more food for the plant to survive.

(With exception to the case of the cactus plant, the stem will do most of the respiration and food making work cos the leaves are too spikey and thin to contribute much to these processes. )

If the question is put in such a way that the ROOTS of the plants are removed, then surely the plant will die.

[janet88]

Hi E3/cg88,

I looked at the question several times and tried to figure out but to no avail...it's strange to use such a diagram and the answer is tiger :? . I just cannot be convinced. What I do know is MAMMALS have 2 stage life cycles except spiny anteater and platypus. Fertilisation is inside the body.

Hey cg88,
:welcome:
I've got a son in P4 and younger gal in K2.

[kohhweelin.010441gmail.010441com]

janet_lee88:

Hi E3/cg88,

I looked at the question several times and tried to figure out but to no avail...it's strange to use such a diagram and the answer is tiger :? . I just cannot be convinced. What I do know is MAMMALS have 2 stage life cycles except spiny anteater and platypus. Fertilisation is inside the body.

Hey cg88,
:welcome:
I've got a son in P4 and younger gal in K2.

haha...Janet, you are right. Was confused by the teacher's answer pertaining to internal fertilization. Removed my first answer in case it start to confuse others. However, all the animals in the options go thru internal fertilization. How about both duck and tiger are warm-blooded? I don't see why they needed to show the life cycle of duck though.

[janet88]

Hi E3,

Mammals give birth to their young alive, because fertilization takes place inside the female body. I don't understand why such a question is tested...it's rather tough for P4 students. For MCQ question, it requires such deep level of thinking.

[kohhweelin.010441gmail.010441com]

janet_lee88:

Hi E3,

Mammals give birth to their young alive, because fertilization takes place inside the female body. I don't understand why such a question is tested...it's rather tough for P4 students. For MCQ question, it requires such deep level of thinking.

What's the objective of this question? Has it anything to do with reproduction? Most sharks, being a fish, also fertilize their eggs internally.

[Jennifer]

CoffeeCat:

For question 1, the best answer is 1. the rest are too far off.

Otherwise there is a possibility that the questions are badly set.

There is always a possibility of a badly set qn. I remind my P3 boy to cross out the most outright wrong choices. That usu. leaves one most probable ans even though we might not understand it.

[Jennifer]

cg88:

2. Open ended Q39. Fatimah decided to cut away all the leaves on his pot of plant in his garden. What do you think would happen to the pot of plant?


Answer : the plant will die eventually.
Reason: the plant cannot get sunlight and will not be ableto make food, hence it will die.

My son's answer: the leaves will grow back.
Reason: there are still food and nutrients stored in the stem, which will enable the leaves to grow back.

the teacher's explanation: the stem is too thin, therefore not much food in the stem!

I think the teacher's ans is quite lame.

Your son's reasoning is correct that new leaves will grow since the stem and roots are still healthy. P4 already learnt plants system right?

[cg88]

Thanks for all the input.


Hi, E3,
This is so confusing for the kid especially the question asked for 'similar stages of life cycle'.
Am i suppose to tell my p6 boy to take note of this and be careful in the PSLE shld such question appear??? :?

Hi Coffeecat/jennifer,
I told the teacher that there is no appropriate answer to this question but she disagree and replied as 'internal fertilisation'. How does a p4 kid know this. Fertilisation is only taught in p5, how to link the two together? Even then, we still classify mammals as having 2 stages, right?


As for the plant, during our revision, we actually went through this question and i told him that if the leaves were only cut off once, it will grow back because of the food already stored in the stem. Now he didnt get this question correct and was questioning why? a thin stem dont really explain my question cos it will still have the xylem and phleom tubes!

I will talk to the HOD to clarify, just to clear the doubts.
Will update again.

Thanks again.

[kohhweelin.010441gmail.010441com]

cg88:

Thanks for all the input.


Hi, E3,
This is so confusing for the kid especially the question asked for 'similar stages of life cycle'.
Am i suppose to tell my p6 boy to take note of this and be careful in the PSLE shld such question appear??? :?

I am very confused too. My understanding is mammals hv 2 stage life cycle. What has it got to do with internal fertilization? How about the young resembles the adult for both duck and tiger? The rest will go thru metamorphosis?

[cg88]

Yes, E3, i will agree with you if the question is phrased as ‘which animals has similarities in their life cycle as that of a duck’ instead of ‘which animals has similiar stages in their life cycle as that of a duck’. See the difference?