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Could someone please explain the immunological comparison for species and the haemoglobin graph as I'm still unsure about these two topics.

Thanks
Reply 561
What do you think will come up on this exam?

Posted from TSR Mobile
Anybody know how to print off AQA past papers?

My teacher manages to shrink them down so there are 2 ''pages from the booklet'' per A4 Sheet.

Seems a waste to print them off full size
Original post by JoeMccarthy
Anybody know how to print off AQA past papers?

My teacher manages to shrink them down so there are 2 ''pages from the booklet'' per A4 Sheet.

Seems a waste to print them off full size


Print properties :biggrin:
Reply 564
Any one know of any bullet pointed formats of all the stuff that needs to be covered on unit 2?

like the file attached but for U2 not U1?
(edited 10 years ago)
Here are some packs which some people may find useful if you want them.

Good luck in the exam in a couple weeks guys! XD

http://sciencemathsmaster.weebly.com/pack.html
Original post by propagation
Print properties :biggrin:



Cheers!
Reply 567
After the unit 1 exam yesterday, I hope I get a good mark in this one..

Posted from TSR Mobile
1 whole week of holiday to revise for this. Hopefully I smash this one as I know I messed up unit 1.
Original post by Son234
Not too late to just start my revision

1 week to memorise the entire unit word for word

1 week full of past papers

looking forward to this 2 weeks :smile:


This was posted from The Student Room's iPhone/iPad App


Yo ! Doing the same here haha.
I was spending so much time on BIOL1 I neglected everything else.
Reply 570
Original post by starfish232
Could someone please explain the immunological comparison for species and the haemoglobin graph as I'm still unsure about these two topics.

Thanks


Serum A (has antigens) is taken from Species 1
Then injected into Species 2 which produces antibodies
Serum B from Species 2 is extracted
Then put into Species 3
If Species 3 has similar antigens to Species 1, they bind to the antibodies.
More closely related = more precipitate = because more antigens bind with the antibodies that are specific to Species 1

We are trying to look for similarities between Species 1 & 3. Species 2 only produces antibodies that are specific to the antigens/proteins of Species 1 so when it gets into Species 3, if the antigens of Species 3 is similar to species 1 then it will bind to more antibodies thus making more precipitate showing they are closely related.

Hope that made some sense! XD Please correct me if I'm wrong :biggrin:

Original post by Nima123
Could someone please explain tissue fluid and the oxygen haemoglobin curve to me...


Tissue Fluid is watery liquid that has glucose, amino acids, 02 etc. It's the means where materials are exchanged :smile:

Blood goes into the arteries then arterioles which then travel into the capillaries. This creates Hydrostatic Pressure at the arterial end.

The Hydrostatic pressure is what forces the tissue fluid out of the capillaries, only small molecules (e.g. oxygen, nutrients) are forced out into the tissues/cells.

This leaves proteins in the blood thus the blood has low water potential.

As we reach the venule end (near the veins), Hydrostatic pressure is low compared to the Hydrostatic pressure in the tissues/cells thus the tissue fluid (bringing with it waste materials, co2 etc) is pushed back into the capillary.

Also, the low water potential causes water to move to the capillaries by osmosis.

Not all tissue fluid returns this way, the alternative way is through the lymphatic system. Which is similar, with it having low Hydrostatic pressure thus Tissue fluid enters it due to the high Hydostatic pressure in the tissues/cells. They are moved by contractions of body muscles back into the heart :biggrin:

The diagram in the Nelson Thornes book is really helps get your head round it :smile:
(edited 10 years ago)
Reply 571
Original post by chelseafan
1 whole week of holiday to revise for this. Hopefully I smash this one as I know I messed up unit 1.


me too!
i fuked up bad
Reply 572
Original post by Loquacious
Yo ! Doing the same here haha.
I was spending so much time on BIOL1 I neglected everything else.


Lol it happens :biggrin:

how are you revising for this? :smile:





This was posted from The Student Room's iPhone/iPad App
Original post by Son234
Lol it happens :biggrin:

how are you revising for this? :smile:





This was posted from The Student Room's iPhone/iPad App


Mhm. :biggrin: I tend to start off with revision for exams that are closer, then work my way in. If that makes sense lol.
I revise by reading and writing at the same time, so like making notes as I go through the topics. After each paragraph, I read that certain section of notes out to myself, then another time without looking at the notes. Recently I've found that me explaining to someone else helps too, and i'm not usually into group revision etc. :smile: What about you ?
Hi i'm busy doing the June 2010 past paper and I cant work out question 5d (ii) ... its about working out the number of different combinations of maternal and paternal chromosomes. does anyone have any idea? Thanks!
Reply 575
Original post by Shinusuke_Akki
Hello everyone, I'm in the process of slowly writing up biology notes on the AQA AS Biology Unit 2 (for the exam in June 2013) would anyone be interested in these notes? I'd be quite happy to post them here if they would be of use to anyone ^^ (As an example of my notes here's my OCR AS Physics Unit 2 G482 thread - if you are taking physics too feel free to check it out http://www.thestudentroom.co.uk/showthread.php?t=2231299&p=41138935) Nice to meet you all, I hope we can all help each other understand our biology lessons better together ^^


I'd love it!
Reply 576
Original post by Loquacious
Mhm. :biggrin: I tend to start off with revision for exams that are closer, then work my way in. If that makes sense lol.
I revise by reading and writing at the same time, so like making notes as I go through the topics. After each paragraph, I read that certain section of notes out to myself, then another time without looking at the notes. Recently I've found that me explaining to someone else helps too, and i'm not usually into group revision etc. :smile: What about you ?


That's pretty cool I also do the same thing

I just revise with my dog

I finish a page, note take, then try to explain and summarise to it

93/100 in core 1 maths A*

98/120 in unit 1 physics A

And 76/100 in unit 1 biology B :frown:

So my revision methods does fairly work lol

But i am going to kill myself with revision for Biol unit 2 to get that A :biggrin:


This was posted from The Student Room's iPhone/iPad App
Original post by chelseafan
1 whole week of holiday to revise for this. Hopefully I smash this one as I know I messed up unit 1.


You never know! You might have done better than you think :smile:
Reply 578
when are you lot starting revision for this?
Bearing in mind i want a little bit of my holiday as a holiday.
Hi could someone please explain why in the june 2010 paper the answer to question 5d(ii) is 8. I don't understand how they got the answer. Also, could someone please how the apparatus used in question 4 works? I don't understand how the potometer allows you to measure rate of water uptake.

Thanks

http://filestore.aqa.org.uk/subjects/AQA-BIOL2-W-QP-JUN10.PDF

http://filestore.aqa.org.uk/subjects/AQA-BIOL2-W-MS-JUN10.PDF