[1234girl]

(Original post by the_alybot)
Can someone explain the Nitrogen cycle to me? I'm revising out of the Heinemann book and CGP revision guide and both say different things about nitrogen fixation.

In the CGP guide it says that nitrogen gas is converted to ammonia and ammonium compounds are made during ammonification from nitrogen compounds by decomposers.

In the Heinemann book, nitrogen is converted to ammonium compounds during nitrogen fixation and there is no mention of ammonification.

Which is right? Could anyone give me a fully detailed explanation of the nitrogen cycle?

Try the OCR book? Or look at an animation on the internet perhaps?

[1234girl]

Hey could someone verify this for me?

In the OCR book on p. 139, the worked example for cystic fibrosis says that q squared is cFcf, but im pretty sure its cfcf? It doesnt make sense to me otherwise, and this book makes a ton of mistakes!

Thanks

[Princess Kawaii]

(Original post by 1234girl)
Hey could someone verify this for me?

In the OCR book on p. 139, the worked example for cystic fibrosis says that q squared is cFcf, but im pretty sure its cfcf? It doesnt make sense to me otherwise, and this book makes a ton of mistakes!

Thanks

yep, it's a mistake. should be cfcf
I know! there's so many of them...at least a couple in each module

[1234girl]

(Original post by Princess Kawaii)
yep, it's a mistake. should be cfcf
I know! there's so many of them...at least a couple in each module

Its really bad, someone put up a list of the errors from F214, but not sure if theres one for f215? Would really appreciate knowing so i could save myself time though

[sd004]

Can someone please outline the steps in sequencing the genome of an organism ?

This is confusing me!

[bambi.m]

Does anybody know what is likely to come up on f215 paper? I have no idea

[Princess Kawaii]

(Original post by 1234girl)
Its really bad, someone put up a list of the errors from F214, but not sure if theres one for f215? Would really appreciate knowing so i could save myself time though

oh do you know where I can find that list for F214? If you have it can you send it to me please

[christrev]

hey guys! anyone have an inkling as to what may come up this time around?

[The Illuminati]

(Original post by bambi.m)
Does anybody know what is likely to come up on f215 paper? I have no idea

(Original post by christrev)
hey guys! anyone have an inkling as to what may come up this time around?

It's not good to make those kind of assumptions. Just make sure you revise everything equally and in detail. Don't assume just because something was in the last paper, it won't be in this one. I am hoping though that there are questions on PCR, electrophoresis and gene therapy because that hasn't really come up recently but you never know.

[otrivine]

(Original post by The Illuminati)
It's not good to make those kind of assumptions. Just make sure you revise everything equally and in detail. Don't assume just because something was in the last paper, it won't be in this one. I am hoping though that there are questions on PCR, electrophoresis and gene therapy because that hasn't really come up recently but you never know.

the chapter about PCR is that the hardest cause i am taking a long time to learn that chapter but the rest are fine

[im so fresh]

i find questions about ecology are ridiculously hard to get the marks on.

[otrivine]

(Original post by im so fresh)
i find questions about ecology are ridiculously hard to get the marks on.

the questions are really similar to unit 2 ones its all about less susceptible to diseases

[im so fresh]

(Original post by otrivine)
the questions are really similar to unit 2 ones its all about less susceptible to diseases

ye but even if you answer it correctly. you still have to use correct terms and link it with other stuff.

[christrev]

those kind of ecology systems usually require key words such as:
genetic variation
gene pool
resistance
evolution

basically the key words towards the end of the meiosis chapter

[--NWzD9--]

On page 178 of the OCR Biology book, regarding human insulin as a engineering case study, it says that single-stranded DNA formed from the reverse transcription of mRNA can be mixed with a supply of DNA polymerase and free DNA nucleotides. Why does it not mention primers, as i had thought that primers would be required for DNA polymerase as the enzyme can only function when double-stranded DNA is present?

[ManPowa]

(Original post by Princess Kawaii)
oh do you know where I can find that list for F214? If you have it can you send it to me please

Ive got it.

Here you go

[andrewpeters]

(Original post by 1234girl)
Its really bad, someone put up a list of the errors from F214, but not sure if theres one for f215? Would really appreciate knowing so i could save myself time though

More than a couple I've found well over 20 in the whole book!

[ManPowa]

January 2012 F215 papers

[Princess Kawaii]

(Original post by ManPowa)
Ive got it.

Here you go

Thanks!

[rainbow_kisses]

Are people using the OCR textbook for revision then?