Biology; Chemistry; Physics: Post your doubts here!

[asd]

C is also double the original mole?

Idk, i closed the link, check it using the formula.

 

[luckywang]

FORGET ABOUT THE NUMBER OF CHLOROPLASTS!!! GOD! IDK THEIR NUMBER IF THE LEAF IS IN DARK OR IN LIGHT. WHAT I KNOW IS PLANTS ARE GREENER IF CHLOROPHYLLS GET LIGHT. WHEN THEY GET LIGHT THEY ABSORB ALL THE OTHER COLOURS IN THE SPECTRUM, EXCEPT GREEN. WHEN THE DON'T THE GREEN LIGHT IS LESS REFLECTED. SO THE COLOUR OF CHLOROPHYLL GOES PALE GREEN ( LIGHT GREEN/CREAMY OR W.E).

got it?

nop... i didnt get it... i tot is the allele causing the cream leaves? since another allele prevent chlorophyll production? so all become cream leaves?

 

[luckywang]

Idk, i closed the link, check it using the formula.

checked... is double too but the volume is bigger and concentration remain...
link here

http://www.xtremepapers.com/papers/...l O Level/Chemistry (5070)/5070_s10_qp_42.pdf

 

[asd]

dude
the plants in shade will produce MORE chloroplast and thus theyll be greener.. asd

K i got it, Shade leaves have more chloroplasts but that is to carry out photosynthesis efficiently even in the little light they get. Thjs has nothing to do with the colour. The colour depends upon the light being reflected and that happens in light that green colour is reflected. this gives leaves the green colour. in dark there is very little light, so green light is not reflected by the same ratio (the ratio decreases) so pale green leaves are developed.
PHew. I guess it's clear now.

 

[asd]

nop... i didnt get it... i tot is the allele causing the cream leaves? since another allele prevent chlorophyll production? so all become cream leaves?

Dude the trait is related with continuous variation, so the appearance can change with environment, ok?

 

[Spidey21]

http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Biology (5090)/5090_w10_qp_21.pdf
Explain Q1 ci)

Anthers and Stigma mature at different times and their position is not in such a manner that would allow them to self pollinate..

 

[ashiqbal]

can anyone explain me the route taken by the urea before excretion.. Renal artery contains urea, and renal artery is like a sub-artery of aorta, so does aorta contain urea?! Urea comes from liver, and the hepatic vein goes to the heart.. it contains urea, so is it like that urea goes all the way through heart to aorta and then to renal artery? This would mean all arteries are going to contain some amount of urea in them! This route might not be possible then.. HELP.

yes it is true!

 

[ashiqbal]

I guess the route i posted was correct! Because in dialysis we draw the blood from artery, and not vein.

exactly!

 

[ashiqbal]

i dont think your logic for Q28 is correct
btw that is what i thought but that is incorrect
the total number of seeds are not same
that is the total no. of seedlings kept in dark are 320+110=430
and in 405+x that are kept in the dark

some of the seeds didnt germinate!

 

[ashiqbal]

however, according to my knowledge of natural selection, adapt and evolution.... leaves in dark will produce more chloroplast... maybe im wrong...

the leaves were not grown in dark in our ATP for gods sake!!! they were grown in shade, where there was less sunlight!!!
and anyway, there are millions of types of leaves, all behaving differently due to billions of genes acting on them! do you honestly believe that the properties of these two leaves will be same??!?!?!?

 

[SilverCrest]

can someone post the guess for chem,bio and physics..

 

[Talhakhan]

Can someone post guess paper for bio,!!!!!!

 

[fatikhalid]

It is actually a very complex formula, if u look at the second link, it is explained that T, I and R are actually co related, and they increase and decrease until an equilibrium is reached. for exams, i suggest u learn only the facts that power is transmitted at high voltage, so that lower current results in low heat loss.

Actually, i tried to grasp the concepts at first, but cudnt find any useful resource book. If u have understood the topic, excellent, otherwise i wud suggest just learning the required effects

well thanx i hav undretsood as much as i needed to..

 

[fatikhalid]

Always remember whenever resistance decreases the current has to increase okay!
If temperature increases that means the resistance decreases which means the current will increase.
Always remember as light or temperature increases resistance will decrease which means current will increase,as the decrease it will increase which means less current.
As you know for a variable resistor if we increase the resistance it will decrease the current ,and decrease resistance will increase the current.

W-O-W that was the best explanation thankyou!..

 

[fatikhalid]

it

40 Two heterozygotes are crossed. Some of the offspring show the recessive characteristic.

What is the probability that one of these offspring that shows the recessive characteristic is
homozygous?
A 0.00 B 0.25 C 0.50 D 1.00

Please anwer this with expalnation

s D that is 1.oo becuase recessive characterstic is always homozygous if it would be hetrozygous the dominant one will show its effect so it is always homozygous!
Furthermore, 1.oo probability means a 100% chance so D is the correct choice!!..

 

[Anam Noor]

some of the seeds didnt germinate!

OHHH
=O
after thinking a lot
i got the reason
that is
THEY CANNOT GERMINATE IN DARK

 

[asd]

OHHH
=O
after thinking a lot
i got the reason
that is
THEY CANNOT GERMINATE IN DARK

LMAO!!
Girl, for germination Light is not needed! It requires optimum temperature, oxygen, and water that's it.

 

[Anam Noor]

is light one of the condition for seed to germinate?

i got the reason why no seed germinate
THAT IS BECAUSE
SEEDS CANNOT GERMINATE IN DARK
they need light condition

 

[Anam Noor]

LMAO!!
Girl, for germination Light is not needed! It requires optimum temperature, oxygen, and water that's it.

ooooppps

 

[Spidey21]

ooooppps

no problem but you gotta be careful atleast at this time...monday its paper.....

asd
dude go easy..