A level Biology: Post your doubts here!

[Akshajistari]

That is a great site.
But a newer version of revision guide isnt there.

Do you mean for our new 2016 syllabus?

 

[My Name]

Do you mean for our new 2016 syllabus?

Yes

 

[Akshajistari]

Yes

Yep none of those are online yet

 

[leenz98]

Can anyone link any past paper question related to the interpretation of absorption and action spectra of chloroplast pigments?

 

[mohmed ahmed soliman]

oh, i get it now, thank you so much. by the way, is this question compatible with the new 2016 syllabus?:
View attachment 59598

can u show address of question

 

[mohmed ahmed soliman]

Can anyone link any past paper question related to the interpretation of absorption and action spectra of chloroplast pigments?

u will find q in textbook saq which is very similar to past papr photosynsis

 

[Bhaijan]

Help its question 16 from nov 2011 paper 1 variant 2
what iis the question? ans is D
what does this mean?

 

[kareem22010]

Help its question 16 from nov 2011 paper 1 variant 2
what iis the question? ans is D
what does this mean?
View attachment 59643

As the temperature gets lower, the phospholipid membrane fluidity decreases which makes it more harder for the cell membrane to fold during exocytosis and in order to overcome that issue,the fluidity of cell membrane increases by increasing the proportion of unsaturated phospholipids( because they are fluid or liquid in structure) so the answer is D.

 

[Bhaijan]

As the temperature gets lower, the phospholipid membrane fluidity decreases which makes it more harder for the cell membrane to fold during exocytosis and in order to overcome that issue,the fluidity of cell membrane increases by increasing the proportion of unsaturated phospholipids( because they are fluid or liquid in structure) so the answer is D.

As the temperature gets lower, the phospholipid membrane fluidity decreases which makes it more harder for the cell membrane to fold during exocytosis and in order to overcome that issue,the fluidity of cell membrane increases by increasing the proportion of unsaturated phospholipids( because they are fluid or liquid in structure) so the answer is D.

tht helped a lot thnx

 

[Peaceful]

Hey guys.

Can someone suggest me good A level Biology books or notes (not summarised.)
I have the Cambrige Coursebook and I would like more help.

PS. This question has probably been asked a multiple times before but I didnt wanna go through the whole thread so sorry for that.
PS. Missed xtremepaper's emojis.

 

[My Name]

Hey guys.

Can someone suggest me good A level Biology books or notes (not summarised.)
I have the Cambrige Coursebook and I would like more help.

PS. This question has probably been asked a multiple times before but I didnt wanna go through the whole thread so sorry for that.
PS. Missed xtremepaper's emojis.

Advanced Biology for you By Gareth Williams
Biological science By DJ Taylor.
Biology in context By Susan Toole.
Cambridge coursebook is good too but it doesn't have everything at least for A2.
About the notes I wanted to ask....Are you doing AL or just AS?

 

[Peaceful]

Advanced Biology for you By Gareth Williams
Biological science By DJ Taylor.
Biology in context By Susan Toole.
Cambridge coursebook is good too but it doesn't have everything at least for A2.
About the notes I wanted to ask....Are you doing AL or just AS?

Thank you very much! Which of these do you find the most helpful?
AS only.

 

[My Name]

Thank you very much! Which of these do you find the most helpful?
AS only.

Welcome.
I use the CIE coursebook.But I get bored or when I cant understand or find something I check the other ones at the library.
Best of luck! You can check the Revision guide.

 

[kareem22010]

can anybody help me and check my answer?

My answer: 2.primary pigments arranged 1.into light harvesting clusters which 3.act as reaction centres. the light harvesting clusters are divided into two photosystems,I and II. 6.the primary pigments are surrounded by accessory pigments which 7.capture light energy for use by photosystems. in cyclic photophosphorylation,photosystem I recieves light energy which 9.excites electrons then the electrons are captured back and 11.passed along ETC to provide energy for 12.atp synthase to manufacture ATP from ADP and Pi.

the sentences highlighted in my answer and the numbers beside them show the point where i think they belong to the markscheme.
am i checking the markscheme the right way? how many marks do you think i should earn for my answer?

 

[Peaceful]

Welcome.
I use the CIE coursebook.But I get bored or when I cant understand or find something I check the other ones at the library.
Best of luck! You can check the Revision guide.

Alright. Thanks a lot for the help.

 

[My Name]

Alright. Thanks a lot for the help.

Welcome.I'm glad I could help.

 

[mohmed ahmed soliman]

in refractory period where Na ion channels become unresponisve can a strong stimulus stimulate it to open

 

[mohmed ahmed soliman]

also in anaerobic respiration there is lactic acid and alcoholic fermentation which one is reversible and why

 

[My Name]

also in anaerobic respiration there is lactic acid and alcoholic fermentation which one is reversible and why

Lactate fermentation is reversible.
The lactate formed can be converted to Pyruvate in presence of oxygen.This can then carry our link reaction.
However the ethanol cant change back to Pyruvate.
Why is a good question.I will tell you when and if I find out.

 

[My Name]

in refractory period where Na ion channels become unresponisve can a strong stimulus stimulate it to open

No it cannot.