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Higher Biology 2012 Discussion

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Reply 40
Original post by OpenArms
Can anybody help me with this question please? :cool:

bio06q29.jpg

and this one...
bio07q3.jpg
I always thought diffusion was from high concentration to low concentration?




Is the first answer D?
And I got confused at the second one aswel, I think it is because the other 2 are active transport. Or maybe diffusion has taken place from high to low until the concentrations have became equal? .. Not too sure
Reply 41
Original post by lollypopyy
my teacher predicted:
Unit1-Transcription/translation
-Phogocytosis
-Respiration
Unit2-Mutation
-Extinction/conservation
-Coping with danger
Unit3-Effect of light in growth
-Water regulation
-Monitoring population/density dependent and independent factors




These have all been essays in the past few years. Doubt they'll be essays again but will definitely come up in sections A & B :smile:
Reply 42
Original post by WeeBundy
Is this true? I've never been told you can do that and I'm scared get penalised for it. Also, can you write essays in bullet points?


Yeah, most definitely, you can write all four if you have time and aren't sure which one you'd get most for :smile:
You can only write the Write notes on....... questions.
DO NOT write the Relevance and Coherance essays in bullet points, unless you want to lose the 2 marks fof relevance and coherance :tongue:
Original post by OpenArms
Can anybody help me with this question please? :cool:

bio06q29.jpg

and this one...
bio07q3.jpg
I always thought diffusion was from high concentration to low concentration?


The first is D I think, because insecicides and herbicides would get rid of the loss of yield from insects and weeds, and the column in D has the most combined loss of yield from insects and weeds - 21 units. You can't just look at column height because that include loss due to disease too which won't be reduced.

For the second question, although you're right and diffusion does happen from a high to low concentration, the end result of diffusion is equal concentrations of a substance on either side because if there are any small fluctuations, the sides are made equal again as the side with more has some diffuse to the side with less. So yes, the answer is chloride.

Hope this helped! :smile:
Reply 44
Anyone able to explain why 2007 Section A qn 12 is B?
I should know it, but my head's just gone completely :tongue:
Reply 45
I think it's because each parent passes on a characteristic on the X chromosome so the father would pass on the only one he has: the colour deficient gene and the mum would pass on a normal gene. The mother's is dominant so it will mask the fathers recessive gene and so the daughter will only be a carrier. If it was a son that was given the colour deficient gene he would be unable to mask it :P does that make sense?
Reply 46
* a characteristic each
Reply 47
Original post by JH2000
I think it's because each parent passes on a characteristic on the X chromosome so the father would pass on the only one he has: the colour deficient gene and the mum would pass on a normal gene. The mother's is dominant so it will mask the fathers recessive gene and so the daughter will only be a carrier. If it was a son that was given the colour deficient gene he would be unable to mask it :P does that make sense?


That is perfect, thank you :smile: :smile: :smile:
can't wait for it to be over, last exam :biggrin: :biggrin: :biggrin:
Reply 49
Your welcome :smile: Good luck for tomorrow :biggrin:
Reply 50
Original post by lapples
That is perfect, thank you :smile: :smile: :smile:


Your welcome :smile: Good luck for tomorrow :biggrin:
Reply 51
Original post by lapples
Anyone able to explain why 2007 Section A qn 12 is B?
I should know it, but my head's just gone completely :tongue:



The mother is unaffected, so no matter what X chromosome she passes down, it will be recessive. The father passes the effected X to his daughter and the Y (which is neither effected nor unaffected as it is sex linked) to his son. The son can therefore never be effected & never be a carrier. However the daughter will be as she has to receive an affected X from her dad & unaffected from her mum. Daughter = carrier

I really bad at explaining things, I know. But hope it helped in some way
Reply 52
Original post by JH2000
Your welcome :smile: Good luck for tomorrow :biggrin:


And yourself :smile:
Reply 53
Original post by LLL17
The mother is unaffected, so no matter what X chromosome she passes down, it will be recessive. The father passes the effected X to his daughter and the Y (which is neither effected nor unaffected as it is sex linked) to his son. The son can therefore never be effected & never be a carrier. However the daughter will be as she has to receive an affected X from her dad & unaffected from her mum. Daughter = carrier

I really bad at explaining things, I know. But hope it helped in some way


Thank you, good luck with the exam tomorrow :biggrin:
Reply 54
Original post by lapples
Anyone able to explain why 2007 Section A qn 12 is B?
I should know it, but my head's just gone completely :tongue:


It says in the question that photoperiodism allows plants to flower at the same time. This means that there will be a greater chance of a plant being able to sexually reproduce over asexual reproduction. This will provide genetic variation.

Hoped that helped
(edited 11 years ago)
Reply 55
i am so nervous.

I keep forgetting the name of the neurotransmitters, and i got told they always come up.
Reply 56
Original post by lapples
Thank you, good luck with the exam tomorrow :biggrin:


Thank you! .. Good luck tomorrow too :smile:
I hope they're nice to us, haha
Reply 57
Original post by LLL17
Thank you! .. Good luck tomorrow too :smile:
I hope they're nice to us, haha


Sames..... Get a feeling they might not though :colone:
Reply 58
Original post by lapples
Sames..... Get a feeling they might not though :colone:


I kow, same :/ because last years paper wasn't too bad, so it'll get worse this year. Plus every other exam I've had so far has been so much harder than expected. But we can always hope biology will be better I suppose haha!
I have a quick question, For question 5e (Section B) on the 2009 paper... I'm absolutley clueless :P I know that they get bigger, but I don't see from the graph why?

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