I have no idea what it wants in terms of proportion but I'm pretty sure it's 5/6 carbons from the two triose phosphates go to regenerate RuBP, and 1 C goes to make a hexose sugar- hence why the calvin cycle has to happen six times to make one glucose molecule. Or would it be 10/12 molecules made would go to regenerating RuBP (from six cycles) and that would cancel down anyway. I just dunno if it wants a ratio or fraction or what :P

I got most of this from the CGP book - the AQA book doesn't really go into much detail how the light independant reaction happens 6 times to make a hexose sugar and just has vague terms like "some triose phosphate molecules are converted..."

I really want to see the answers D:

Reply 63

Tikara

Original post by sechdent8

its a question involving a diagram, you have to see it

Just found the answers to the unit 4 exam style questions :biggrin:

and yes the answer was 5 out of 6 (I've explained above :smile:

) or you could have had a percentage

Nelson Thornes Unit 4 exam answers AQA Biology.pdf139.8KB

Reply 64

hollywils

Original post by neeloo

Ive posted links to the paper, mark scheme ect

Please could you send me the links to the Jan 13 paper and mark scheme?! :smile:

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Reply 65

Tikara

Original post by hollywils

Please could you send me the links to the Jan 13 paper and mark scheme?! :smile:

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http://www.thestudentroom.co.uk/showpost.php?p=42068880&postcount=20

Reply 66

hollywils

Original post by Tikara

http://www.thestudentroom.co.uk/showpost.php?p=42068880&postcount=20

Thanks!

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Reply 67

igloo1

Original post by Tikara

So is everyone here resitting then?

I guess so since AS people won't have learnt unit 4 yet.. presuming they're doing the units in order.

Reply 68

sals1234

Hey guys!

im stuck on question 2B (calculate the maximum growth rate) on the January 2010 BIOL4 paper!

any help? :smile:

thank you!!

Reply 69

s24a

normally these threads are heaving with people and their questions/opinions/ideas! where is everyone?

Reply 70

lcj0503

Original post by s24a

normally these threads are heaving with people and their questions/opinions/ideas! where is everyone?

Did you firm Bham?

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Reply 71

Tikara

Original post by sals1234

Hey guys!

im stuck on question 2B (calculate the maximum growth rate) on the January 2010 BIOL4 paper!

any help? :smile:

thank you!!

Okay, just had a look at this one and it isn't too hard - I'm not really sure when this is taught in Biol4 though

but anyway, the growth rate is going to be the gradient in the line, which is change in y / change in x, or change in mass / change in age.

The maximum growth rate is therefore when the line is the steepest, when there is the greatest rise in mass in the shortest rise in age. Usually with questions like these there will be a two points at nice places just hitting on the grid exactly.

So I picked the points at 20 and 22.5 days on the dotted line as they're on the steepest part of the curve (you could pick two points at anywhere on this steepest line and get the same answer but I chose these cause they're easier) and the change in mass is 100 so 100/2.5 = 40mg/day

TL;DR points at 20 and 22.5 days --> 100/2.5 = 40 :smile:

hope that helped mate

(edited 10 years ago)

Reply 72

Tikara

Original post by s24a

normally these threads are heaving with people and their questions/opinions/ideas! where is everyone?

then start!!! there must just be mainly resits unfortunately so not as much activity :frown:

but it's safe to say I no longer worry about the 6/5 markers at the end of biol4 now I know of the unholy 25 mark essay at the end of biol5 :tongue:

My main tips would be 1. look at the amount of marks given! It'll indicate how much the question wants and I ran out of time when I did the exam because I gave giant answers for 3 markers

and 2. read that darn question carefully!!! I know it seems obvious but the wording of every question is specific to get certain bits of information out of you!

also, how is every one gonna do the questions at the end? are you gonna do them first and then the exam or the other way round?

(edited 10 years ago)

Reply 73

Tikara

can anyone help with question 2a on page 84? I thought it was sticklebacks but according to ms it's them and dragonfly nymphs. Is the book meant to ask for secondary consumers?

Reply 74

kdk

Original post by Tikara

can anyone help with question 2a on page 84? I thought it was sticklebacks but according to ms it's them and dragonfly nymphs. Is the book meant to ask for secondary consumers?

I think u r right, sticklebacks are the only tertiary consumers :smile:

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Reply 75

Chewy29

Does anyone know where to get the markschemes for the nelson thornes book?

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Reply 76

Tikara

Original post by Chewy29

Does anyone know where to get the markschemes for the nelson thornes book?

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They're all on this thread

the unit 4 exam answers: http://www.thestudentroom.co.uk/showpost.php?p=42756888&postcount=64

and all the chapter exam answers here :smile:

: http://www.thestudentroom.co.uk/showpost.php?p=42733783&postcount=55

Reply 77

Chewy29

Original post by Tikara

They're all on this thread

the unit 4 exam answers: http://www.thestudentroom.co.uk/showpost.php?p=42756888&postcount=64

and all the chapter exam answers here :smile:

: http://www.thestudentroom.co.uk/showpost.php?p=42733783&postcount=55

Thanks. Starting my revision for this unit today :smile:

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Reply 78

Farid1

I wondering whether you have to answer the 5-markers at the end in a certain order. For example, if the 5-marker is about speciation and so to explain and describe geographical isolation does it matter what order you make your 5 points in or does it have to be in the correct order for you to get the 5 marks.