A level Biology: Post your doubts here!

[asma tareen]

right. and since osmosis is nothing but a special type of diffusion of water molecules only, i guess it will fall under the diffusion category.

Yeah I think cux facilitated diffusion Is highly specific but I dunno .....sorry I cant find the answer for that in book :/

 

[sitooon]

Heyey guys... just wanted to know if leaf abscission is included in the syllabus or not... well is it??

yes it is

 

[daredevil]

yes it is

urrghh dammit -_-

well thanks anyways

 

[daredevil]

yes it is

look in the screenshot it isn't mentioned .... :O
it only mentions the role of abscisic acid in stomatal closure.

 

[sitooon]

look in the screenshot it isn't mentioned .... :O
it only mentions the role of abscisic acid in stomatal closure.

but i saw question regarding leaf abcession

 

[daredevil]

but i saw question regarding leaf abcession

these people are just too damned confusing!!! :O

 

[ahmed abdulla]

Hi everyone ,
I went yesterday through genetic crosses and today tried to solve some papers ,
in some questions they are using xx/xy when female/male involved and other crosses they are using crosses which involve other locus
like the question i posted below ,
any one has clue when to use xx/xy or eg use W^A /W^B ( i know this is not maths )
and can someone do the question posted below?

 

[6Astarstudent]

Hi everyone ,
I went yesterday through genetic crosses and today tried to solve some papers ,
in some questions they are using xx/xy when female/male involved and other crosses they are using crosses which involve other locus
like the question i posted below ,
any one has clue when to use xx/xy or eg use W^A /W^B ( i know this is not maths )
and can someone do the question posted below?

when its linked to sex its X/Y, when you see homozygous/heterozygous its W^A/W^B, when you see dominant recessive its I/i

I'll go from left to right, top to bottom
key: W^A is resistant, W^B is susceptible

W^A W^B W^A W^B they must both be heterozygous because they have susceptible offspring
W^A W^B W^A W^B
W^A W^A W^A W^B W^B W^A W^B W^B now you put them the possible ways they can arrange
resistant resistant resistant susceptible only W^B W^B is susceptible because heterozygous is resistant too according to Q

 

[ahmed abdulla]

when its linked to sex its X/Y, when you see homozygous/heterozygous its W^A/W^B, when you see dominant recessive its I/i

I'll go from left to right, top to bottom
key: W^A is resistant, W^B is susceptible

W^A W^B W^A W^B they must both be heterozygous because they have susceptible offspring
W^A W^B W^A W^B
W^A W^A W^A W^B W^B W^A W^B W^B now you put them the possible ways they can arrange
resistant resistant resistant susceptible only W^B W^B is susceptible because heterozygous is resistant too according to Q

This question is related to sex , male and female ?

 

[daredevil]

Yaar is the effect of other chemicals (like nicotine ) on synapses included in our syllabus??

 

[daredevil]

Hey... someone please give me notes or any stuff on the highlighted syllabus outcome :O
We haven't done it in class >_<
thanks for the help in advance :`)

 

[daredevil]

Hey guysss.. if anyone still alivee.....

well u got anything on speciation esp. sympatric speciation?? any help or notes will be greatly appreciated... thankss =)

 

[joanna omar]

u can look at the standard booklet if there is one.

Okaaay thanks ,, do u have any links to that ?

 

[joanna omar]

AND PLEASE Anyyonee I need any guiddes or points that will help me proceed with paper 5 as itss so HARD !

 

[Igcse stuff]

Hey guys, were can i find good practical notes for P3 and P5.... and how do you prepare for the questions in P4 section B?

 

[1357911]

Hey guys, were can i find good practical notes for P3 and P5.... and how do you prepare for the questions in P4 section B?

for paper 5 have a look at this link please. I hope u get all the guide u need.
https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/
For paper 4 section B, My teacher advised me : Do 2 question daily, i.e one paper write all the points in the correct order. and underline or highlight alll the important points, It will be easier for the examiner to see that u have covered up all the points, Plus explanations with diagrams. Diagrams are really very important. it carries quite a lot of marks. check wheter u have covered up all the answers as the mark schemme says. And one thing more. In part B there are many repeated questions in every paper. Mark them or highlight them U may not need to practise those agaian. u already have an answer to those questions so u may not repeat and learn from the previous answers

AND PLEASE Anyyonee I need any guiddes or points that will help me proceed with paper 5 as itss so HARD !

https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/

 

[1357911]

Yaar is the effect of other chemicals (like nicotine ) on synapses included in our syllabus??

That part is the most important part of the syllabus.

 

[1357911]

Hey guysss.. if anyone still alivee.....

well u got anything on speciation esp. sympatric speciation?? any help or notes will be greatly appreciated... thankss =)

Which book do u use. ? the one which i have somewhat covers all the important points. U only need a few things to be learnt. Because the question based on this are repeated again and again in almost every paper in twisted ways. but the answers are the same.

 

[Igcse stuff]

for paper 5 have a look at this link please. I hope u get all the guide u need.
https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/
For paper 4 section B, My teacher advised me : Do 2 question daily, i.e one paper write all the points in the correct order. and underline or highlight alll the important points, It will be easier for the examiner to see that u have covered up all the points, Plus explanations with diagrams. Diagrams are really very important. it carries quite a lot of marks. check wheter u have covered up all the answers as the mark schemme says. And one thing more. In part B there are many repeated questions in every paper. Mark them or highlight them U may not need to practise those agaian. u already have an answer to those questions so u may not repeat and learn from the previous answers


https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/

Thanks alot!!!

 

[Igcse stuff]

for paper 5 have a look at this link please. I hope u get all the guide u need.
https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/
For paper 4 section B, My teacher advised me : Do 2 question daily, i.e one paper write all the points in the correct order. and underline or highlight alll the important points, It will be easier for the examiner to see that u have covered up all the points, Plus explanations with diagrams. Diagrams are really very important. it carries quite a lot of marks. check wheter u have covered up all the answers as the mark schemme says. And one thing more. In part B there are many repeated questions in every paper. Mark them or highlight them U may not need to practise those agaian. u already have an answer to those questions so u may not repeat and learn from the previous answers


https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/

By the way, can you kindly upload pics of your section B essays? I hope it's not too much to ask for....