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F215 - Revision thread 13th June 2011

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Does anyone have or know the raw mark grade boundaries/raw to ums conversion from last year?
Can't find them anywhere :redface:

Edit: don't worry, found them! :tongue:

(edited 12 years ago)

Reply 1021

Waqar Y

Original post by Arab_Empress

Yeah I didnt quite get it either, the example in the book is quite confusing

What do you mean by linked genes?

Reply 1022

science rules! :)

Original post by Arab_Empress

Yeah I didnt quite get it either, the example in the book is quite confusing

Linkage is when two or more genes are located on the same chromosome. thsi is usually because they don't segregate independently during anaphase I of meiosis. It reduces the number of phenotypes resulting from the cross. I just carry out a normal cross but take all the information they give you into consideration- seems to work ok :smile:

Reply 1023

science rules! :)

Original post by ekta9

Anyone think Primary and secondary productivity will come up again as there was alot about it in Jan 2011?

I think that its really unlikely- anyway it is one of the topics which at least you can think about and apply to real life- growing of plants, control light levels, temp, genetically engineer to be pest resistant, apply herbicides, fungicides. etc. And for animals- zero grazing, kill before adulthood to minimise heat loss, treat with steroids, selective breeding etc. :smile:

Reply 1024

786girl

how would you answer;
outline how animals can be genetically engineered for xenotransplantation"

:s

Reply 1025

786girl

and what about the Galapagos Island??! it says we need to know examples...ummm yeahh I havemt learnt any! I have a feeling they will ask about it!! eeeew I hate OCRs attempt at trying tp test "application of knowledge" just so that they can tick their own boxes!

Reply 1026

icarus_xx

Original post by 786girl

how would you answer;
outline how animals can be genetically engineered for xenotransplantation"

:s

I would assume that you can use germline therapy to insert human antibodies onto the cells of the animal used for xenotransplantation. This would reduce the chance of rejection in the humannn.

For the Galpagos, goats are a good one. They eat the same food as the tortoises and trample their nesting sites, which messes things up for them.
I also believe the red quinine tree outcompetes the natural shrubbery, changing the environment of the island - messing with light levels, etc.

This is from memory mind, and I need to do more on the whole topic. :colondollar:

Reply 1027

Tobia_s

Original post by twelve

Thats actually a difficult one...

I've got a couple:
- reproductive cloning is the production of a complete new organism, whereas non-reproductive eis the production of cells, tissues or organs.
- reproductive cloning happens naturally - in identical twins, plants(runners, suckers..), fungi (budding) and bacteria(binary fission)

I thought of a few more, but they weren't consistent with animals and plants...

Thanks

Now I've got at least 2 clear-cut ones :smile:

Reply 1028

ekta9

Original post by science rules! :)

Ah I see! I haven't covered any of ecosystems yet.. Leaving that for tomorrow! Think I can cover it all in one day if I begin early?!

Reply 1029

ekta9

Original post by 786girl

how would you answer;
outline how animals can be genetically engineered for xenotransplantation"

:s

Do you have the CGP book? That explains it really well!

Xenotransplantation is about the transfer of cells and organs from animals to different species (humans!). Basically theres 2 ways how animals can be genetically engineered:
1) Genes for HUMAN cell surface proteins are INSERTED into animals DNA. This is to reduce the risk of transplant rejection.
2) Genes for ANIMAL cell surface proteins can be removed/inactivated so reduce risk of rejection.

(edited 12 years ago)

Reply 1030

jak67m

hey guys, do you rekon i can finish module 1(cellular control) of this book if im at it from 23.00 till 5.00 - with 30 minutes break every 1 and a half hours... ?? yes or no?

Reply 1031

heartskippedabeat

Original post by jak67m

hey guys, do you rekon i can finish module 1(cellular control) of this book if im at it from 23.00 till 5.00 - with 30 minutes break every 1 and a half hours... ?? yes or no?

Yeah, but if I were you I'd just read over it a couple of times or quickly read over the whole module now, then get up early tomorrow and spend the whole day revising :smile:

Reply 1032

greenford

Original post by heartskippedabeat

Does anyone have or know the raw mark grade boundaries/raw to ums conversion from last year?
Can't find them anywhere :redface:

Edit: don't worry, found them! :tongue:

http://www.ocr.org.uk/download/admin/ocr_47951_admin_mk_grd_bound_jun_10.pdf

Reply 1033

jak67m

Original post by heartskippedabeat

Yeah, but if I were you I'd just read over it a couple of times or quickly read over the whole module now, then get up early tomorrow and spend the whole day revising :smile:

Oh but I always say "I will wake up early"... but till date... I HAVE NEVER GOT UP EARLYYY... and i work more efficiently at night... so hopefully i can do it... anyway wish me luck im gna start nw and will be back if i need help ( not that anyone will be on here ) haha x

Reply 1034

786girl

lol the genomes and gene therapy stuff is quite intetesting hehe

can someone help me with this:
-biological species concept & phylogenetic species concept (are we just meant to know about the difference?)

-genetic drift!

that is alll i promise!

Reply 1035

heartskippedabeat

Original post by jak67m

Haha fair enough :smile:

I'll probably be on here, I'm not good at taking my own advice so will probably be up til 2 or 3 ish :redface:

Good luck! x

Reply 1036

Popey93

Gone over unit one and half of unit 2 on the spec aswell as notes from the revision guide... Still don't feel ready at all. :frown:

Why is there so much stuff to learn? we will only get asked on about 40% of it, or at least it seems like a very small amount in the past exams I've done.

Reply 1037

Princess_perfect786

in neuromuscular junctions what is the T system? in the heinemann book it says " depolarisation waves travel down tubules (T system)"

Reply 1038

Bullit

Original post by Princess_perfect786

in neuromuscular junctions what is the T system? in the heinemann book it says " depolarisation waves travel down tubules (T system)"

Its just the name for the curve on the membrane (pictured in the book). All you'll need to know about it is what you just said; depolarisation waves travel down it . This then causes Calcium ions to be released from the sarcoplasmic reticullum blah blah