Biology; Chemistry; Physics: Post your doubts here!

[Al-Anoud]

i dnt take igcse but mi guess would be (referring to CO2, as u stated) plants need oxygen for respiration and xtremely high levels of co2 will prevent plants from respiring

thnxx alot

 

[Al-Anoud]

It allows a good supply of fresh air to enter and leave the plants. The buildup and reuse of the same carbon dioxide could damage the plant and hinder the process of photosynthesis, producing insufficient glucose/carbs. Oxygen needed for respiration must also be replaced by cleaner air from outside

thankuu!

 

[robinhoodmustafa]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_w09_qp_2.pdf
sum1 please help me with question 5 part d

 

[Snowysangel]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_w09_qp_2.pdf
sum1 please help me with question 5 part d

It'll be inverted.

 

[Snowysangel]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_w09_qp_2.pdf
sum1 please help me with question 5 part d

What's the answer to 3a tho? Are those the right ventricle/auricle?

 

[asma tareen]

What's the answer to 3a tho? Are those the right ventricle/auricle?

it would be auricle

 

[AhsanAfzal]

it would be auricle

auricle or atrium??? i havent heard about auricle anywhere

 

[AhsanAfzal]

auricle or atrium??? i havent heard about auricle anywhere

ohh they both are same

 

[AhsanAfzal]

where on this paper can we draw a diagram? the marking scheme says we can draw graph or diagram for this question. there is no space for diagram

 

[Hskk]

k

Draw a-i) plz

 

[Hskk]

where on this paper can we draw a diagram? the marking scheme says we can draw graph or diagram for this question. there is no space for diagram

You'll get the marks if you don't draw a diagram and explain well, otherwise, maybe just draw on the lines.

 

[usama321]

k

Draw a-i) plz

i think it should be like this

 

[irfan.kheerdali]

state and explain the effect of sweating on the urine produced during a hotter day?? help plz

 

[Munibn]

Hi, i've been having a problem with Radioactivity and Electronics CRO. In Radioactivity there's this formula, (1/2)^n or something like that in the topical. Can anyone explain that to me? and in CRO, i had a problem in J 07 P1 Q 37. Thanks in advance

 

[usama321]

Hi, i've been having a problem with Radioactivity and Electronics CRO. In Radioactivity there's this formula, (1/2)^n or something like that in the topical. Can anyone explain that to me? and in CRO, i had a problem in J 07 P1 Q 37. Thanks in advance

yup that is the formula for half life.
for the other question, the answer is C. This is because the time base setting (x axis) states that each div represents 2ms. Now, on complete wave takes 2 divs in the horizontal axis. So 2*2 = 4ms

 

[Hskk]

View attachment 25656

i think it should be like this

Oh okay, I'm still a wee bit unsure, but probably there's no other way. Btw, the arrows will be in the opposite direction to what you've drawn.

 

[usama321]

Oh okay, I'm still a wee bit unsure, but probably there's no other way. Btw, the arrows will be in the opposite direction to what you've drawn.

and i just lost one mark

 

[Snowysangel]

state and explain the effect of sweating on the urine produced during a hotter day?? help plz

On a hot day you sweat more so a large amount of water is lost through sweeting. To retain as much of the remaining water in the body as possible, the hypothalamus stimulates the pituitary to release ash, which helps to absorb more water in the nephorons. Hence the urine os concentrated

 

[Snowysangel]

it would be auricle

But is the other lette marked st the ventricle?

 

[Snowysangel]

What are the problems of recycled water in the household? Other than its quality and possible pathogenic agents still found in it?