Q&A - P4 Science

[J and J]

AgonyMum:

Hi,

At which stage of the life cycle of a mosquito is it easiest for us to get rid of them?
The answer sheets of 2 different books state laval and pupal stages.
I understand that it is because they cannot fly at these 2 stages (as compared to the adult mosquito). BUT shouldn't it be easiest to get rid of the EGGS??

I think it is easier to spot out the mosquito lava or pupa than the egg with naked eyes.

Can someone please enlighten me? Thanks!

Oops, 1 more question:

Can a seed germinate in a dark room(water and air are present)?
One book's answer is yes, since a seed only needs water, air and warmth to germinate. Another book's answer is no.

Which is correct and why? TIA!

The first one correct. As light is only needed when its baby leaf come out of the ground for photosynthesis.

[Niedino]

AgonyMum:

Hi,

At which stage of the life cycle of a mosquito is it easiest for us to get rid of them?
The answer sheets of 2 different books state laval and pupal stages.
I understand that it is because they cannot fly at these 2 stages (as compared to the adult mosquito). BUT shouldn't it be easiest to get rid of the EGGS??

Can someone please enlighten me? Thanks!

Oops, 1 more question:

Can a seed germinate in a dark room(water and air are present)?
One book's answer is yes, since a seed only needs water, air and warmth to germinate. Another book's answer is no.

Which is correct and why? TIA!

Hi all,

Its been a long time since I visited the forum. Let me shed some light on the 2 questions.

1. It is easiest to get rid of the larva and pupa as you just need to prevent them from taking in air. As for the mosquito eggs, you'll need them to hatch before the larva needs air. If not, you'll probably need a very fine sieve to sieve out the eggs to get rid of them.

2. There is no need for sunlight. In the Primary Science syllabus, seeds need water, warmth and oxygen to germinate. Sunlight is needed when the stored food in the seed leaves are used up by the germinating plant and the first leaves are grown to help the plant make food via photosynthesis.

Hope that helps!

Niedino

[AgonyMum]

Thanks very much, J and J, Niedino !


:thankyou:

[Jamesbond]

http://i46.tinypic.com/25aisuo.jpg\">


Can u pl give the answer with explanation...Thanx.

[Niedino]

Jamesbond:

http://i46.tinypic.com/25aisuo.jpg\">


Can u pl give the answer with explanation...Thanx.

Hi Jamesbond,

The question tests on the understanding of the functions each part plays.

(1) is out as the gullet is a muscular tube, hence the heading \"Does not have muscles\" cannot be used to classify it.

(2) is the correct answer

(3) is out as the stomach and small intestine does not store undigested food, while the gullet transports partially digested food.

(4) is out as the stomach does not absorb food into the bloodstream.

Hope it helps!

Niedino

[Jamesbond]

Niedino:

Jamesbond:

http://i46.tinypic.com/25aisuo.jpg\">


Can u pl give the answer with explanation...Thanx.

Hi Jamesbond,

The question tests on the understanding of the functions each part plays.

(1) is out as the gullet is a muscular tube, hence the heading \"Does not have muscles\" cannot be used to classify it.

(2) is the correct answer

(3) is out as the stomach and small intestine does not store undigested food, while the gullet transports partially digested food.

(4) is out as the stomach does not absorb food into the bloodstream.

Hope it helps!

Niedino

:thankyou: :salute: :salute:

[Jamesbond]

http://i45.tinypic.com/29uq6mf.jpg\">


Pl help me answer

[Jamesbond]

Rubber is used for car tyres....Give a reason why it is used?


Will u say It is strong or it is waterproof.....Becos they r just asking a reason..what will b the priority? Pl hlp.. :yikes:

[Jamesbond]

teh_oh:

Hi,

Appreciate assistance on the following:-

Q: The female mosquito sucks blood so that she has enough energy to lay eggs. True/False

Child's Ans: False (because she sucks blood for nutrients, not energy)
Ans Key: True
___________________________________________

Q: Why is air classified as matter?
A: Has mass
B: Occupies space
Can be compressed

Child's Answer: A and B
Ans Key: A, B and C
_____________________________________________

http://i42.tinypic.com/17efxj.jpg\">

Child's Answer : 4
Ans Key: 2
Why?

Thanks!

can anybody clear the first two questions...No proper explanations so far...

[Niedino]

Jamesbond:

http://i45.tinypic.com/29uq6mf.jpg\">


Pl help me answer

Hi Jamesbond,

I would say (4), since the germination is in a dark cardboard, so the food in the seed leaf would all be used up.

Hope it helps!