Q&A - PSLE Science

[atutor2001]

Verysuperkiasu:

sorry, I'm quite bad in understanding electricity. If batteries are conductors of electricity (then shouldn't electricity still flows) isn't flow of electricity = flow of current? that is, if batteries still can conduct electricity, shouldn't current flow as well?

You may like to visualise it as that if there are 5 batteries in one direction and 5 batteries in the opposite direction then the end result is the same as if there is NO (0) battery in the circuit (5 - 5 = 0). NO current i.e. electricity will flow in a circuit that has NO battery connected. Hope it helps.

Thank you Sun_2010 for your help.

[Verysuperkiasu]

Thank you atutor and sun_2010 for your explanation. I understand now.

[Koky462]

I have an question on the method of reproduction from my son’s exercise.


x - Man, Frog, Polar bear\t\t
y - Yeast, Amoeba, Paramecium
\t
a)What is the main difference between the two methods of reproduction for X & Y?
b)Name the reproduction method under the sub-heading X.

[Selfan4ever.05005423]

Koky462:

I have an question on the method of reproduction from my son's exercise.


x - Man, Frog, Polar bear\t\t
y - Yeast, Amoeba, Paramecium
\t
a)What is the main difference between the two methods of reproduction for X & Y?
b)Name the reproduction method under the sub-heading X.

b) External

[Selfan4ever.05005423]

Koky462:

I have an question on the method of reproduction from my son's exercise.


x - Man, Frog, Polar bear\t\t
y - Yeast, Amoeba, Paramecium
\t
a)What is the main difference between the two methods of reproduction for X & Y?
b)Name the reproduction method under the sub-heading X.

b) External

[Selfan4ever.05005423]

Koky462:

I have an question on the method of reproduction from my son's exercise.


x - Man, Frog, Polar bear\t\t
y - Yeast, Amoeba, Paramecium
\t
a)What is the main difference between the two methods of reproduction for X & Y?
b)Name the reproduction method under the sub-heading X.

b) External

[bestwishes]

Selfan4ever♥23:

Koky462:

I have an question on the method of reproduction from my son's exercise.


x - Man, Frog, Polar bear\t\t
y - Yeast, Amoeba, Paramecium
\t
a)What is the main difference between the two methods of reproduction for X & Y?
b)Name the reproduction method under the sub-heading X.

b) External

a) X: Sexual reproduction (involves 2 parents of opposite sexes; involves fertilisation)
Y: Asexual reproduction (involves a single parent; not involve fertilisation)

Frogs in X -- external fertilisation
Mammals in X -- internal fertilisation
Yeast in Y -- budding (a kind of cell division)
Amoeba & Paramecium in Y -- binary fission (a kind of cell division)

[Koky462]

Thank you Selfan4ever23 & bestwishes for your replies!

[elkniwt]

Hi,


Need some advises on this qn :

Which of the following is/are the correct functions of the trunk of a rain tree?
A. It transports water and mineral salts to all parts of the plant.
B. It keeps the plant upright.
C. It twines round a support to help the plant reach for more sunlight.
D. It transports food from the leaves to all parts of the plant.

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

The answer in answer key is (4). My dd’s questions are "is it correct to say the trunk transports food, isn’t it the phloem that does that?" And she also asks, if a qn asks for the function of a trunk, can she actually write "it transports food to all parts of the plant"??

Many thanks.

[anneshirleygilbert]

Can these two terms "chemical energy" and "chemical potential energy" be used interchangeably in answering Open-Ended questions in PSLE? Do they mean the same thing? I see these terms in different answer sheets. Please help.