Q&A - PSLE Science

[wkong]

Need help for another question:


The graph below shows the changes in the size of a population of food producers and a population of primary food consumers in a pond last year. The amount of light and temperature available is also super-imposed on the graph to show how they have affected the organisms.

http://postimage.org/image/mcbxbptw/


Which of the following statements about the graph are not true?
A: The higher the temperature, the fewer the organisms in the pond.
B: Temperature and light affect the growth of organisms in the pond.
There were more primary food consumers than food producers in November.
There were equal number of primary food consumers and food producers only in July.


1) B and C only
2) A and D only
3) A, C and D only
4) A, B, C and D

[wkong]

starlight1968sg:

meimeitan:

Hi Good morning,


Anyone can help the following question?

Tubes grow from the pollen grains towards the ovary to pass __________
(1) the pollen grains to the ovules
(2) nutrients and water to the ovules
(3) the female egg cells to the ovules
(4) the male reproductive cells to the ovules

Thanks.

I think is (1). Let us hear what the other say.

My answer is 1 too

[starlight1968sg]

wkong:

starlight1968sg:

[quote=\"meimeitan\"]Hi Good morning,


Anyone can help the following question?

Tubes grow from the pollen grains towards the ovary to pass __________
(1) the pollen grains to the ovules
(2) nutrients and water to the ovules
(3) the female egg cells to the ovules
(4) the male reproductive cells to the ovules

Thanks.

I think is (1). Let us hear what the other say.

My answer is 1 too :D[/quote]On second thought, the pollen grains did not really get into the ovules but it is the male reproductive sex cells in the pollen grains that reach the ovules via the pollen tubes grown from pollen grains.

I am confused! :roll:

[starlight1968sg]

wkong:

Hi All,


Need help for the following:

Paul classified some examples of forces into two groups as shown in the table.

http://postimage.org/image/19r192cv8/


Which of the above actions is/are incorrectly place in the table?
1) A only
2) C only
3) B and C only
4) B, C and D only

What is the ans?
If \"die-die\" must choose, I would go for (2) ie option C.

A) looks like push as we are flattening something.
B) We are going up the hill thus looks like pushing ourselves uphill.
D) It is about gravitational pull.

For flying a kite, it is pull and release of the string attached to a flying kite,

[jesschan]

Can someone please assist with the following question? Did the bulb fuse at the 6th or 7th battery?



Q: State what happens when the 6th battery was added. Explain.

http://postimage.org/image/30dah69es/

[wkong]

jesschan:

Can someone please assist with the following question? Did the bulb fuse at the 6th or 7th battery?



Q: State what happens when the 6th battery was added. Explain.

http://postimage.org/image/30dah69es/

The bulb fused at the 7th Battery.

At the 6th battery, the bulb reached its maximum limit.

[jesschan]

Thanks, wkong. But my son had the same answer and was marked wrong… I wonder what is wrong with the answer…

[atutor2001]

jesschan:

Thanks, wkong. But my son had the same answer and was marked wrong.... I wonder what is wrong with the answer....

Is the word \"brightest\" in your son's answer? Maybe that is the keyword they are looking for. Science marking scheme can be quite silly at times, especially in school.

[jesschan]

atutor2001:

jesschan:

Thanks, wkong. But my son had the same answer and was marked wrong.... I wonder what is wrong with the answer....

Is the word \"brightest\" in your son's answer? Maybe that is the keyword they are looking for. Science marking scheme can be quite silly at times, especially in school.

Yeah, he did. But his teacher said that the bulb fuses at the 6th battery?!! :? And he lost 2 marks for the this, not knowing why....

[tisha]

http://postimage.org/image/21pr64bo/



Need help with this Q from Catholic High SA1 2010 Science paper.