The Student Room Group

The Biology AS-level Thread

Scroll to see replies

Ahh, I'm on OCR!

Posted from TSR Mobile
We have huge 8/9 mark questions :frown:

Posted from TSR Mobile
Original post by kayleighjadex
We have huge 8/9 mark questions :frown:

Posted from TSR Mobile


10 marks here :colonhash:
Told you collagen was on our spec :tongue: ahh bad luck about the 10 markers!

Posted from TSR Mobile
Good luck everybody! :smile:

Posted from TSR Mobile
Hi there!
Doing research into the cytoskeleton, and I was wondering if it can be observed with a light microscope? The width of the microtubles are about 25nm, which is smaller than the resolution of the light microscope, however if you were to stain the sample using actin staining, would you be able to see the structure at all? Or would an electron microscope be necessary?
Thanks
Hi,

I've just started OCR AS Biology, and I've got a few questions about it. Firstly, out of all my subjects (Bio, Chem, Spanish & Eng Lit), I think i've been struggling with Biology the most. I know it should be easier than Chemsitry but there's something about it that makes it more confusing/complicating. I've got quite a good memory, so I don't think the case is me not being able to remember the content.

What I'm really annoyed at is how the mark scheme is SOOO specific and that there are loads of discrepancies between between textbooks/online sources/what teachers say. I would appreciate it if someone suggested how I can go about doing my extra work for biology, like what reliable websites i can use and be sure that if i use a specific term or phrase from the that source it'll be on the mark scheme, because i feel as though i know what the answer is but i word it in such a way that it ends up being wrong :/

Also, to what level of detail do i need to know the content? Different sources have different levels of content and i'm not quite sure whether i should for example know that a part of the cytoskeleton is an actin filament because my teacher has never taught us this...

Thanks (and apologies if this is confusing).
(edited 9 years ago)
Does anyone know anything like http://chemrevise.org/ for AQA Biology AS? thanks
Hi all,
I am doing the AS SNAB bio coursework, the topic I am doing it on, how HPV vaccines can be used to reduce rate of cervical cancer.
Finding it extremely hard to actually start writing my introduction.
Could anyone help out asap please?
Thanks in advance...
Original post by Ray.Inspiration
Hi all,
I am doing the AS SNAB bio coursework, the topic I am doing it on, how HPV vaccines can be used to reduce rate of cervical cancer.
Finding it extremely hard to actually start writing my introduction.
Could anyone help out asap please?
Thanks in advance...


Generally speaking, in an introduction you have to 'set the scene' ie why is the rest of your work relevant? So I would:
- give a brief overview of cervical cancer and CIN (what is it, epidemiology etc)
- briefly how HPV 'causes' cancer/precancerous changes (if you do not already have a section on this)
- types of HPV, how HPV is spread and different vaccines available (gardasil/cervarix)
Reply 951
Hello c:
Doing AS edexcel Biology and i was just wondering, what revision guides would you guys recommend? Because atm i'm using CGP and also the edexcel biology textbook. Finding Biology good atm, but idk. Maybe CGP simplifies everything too much? Not very challenging.

My biology teachers.. are :cry2:
I'm self teaching basically.
I've just done my second practise exam and I'm still getting a 'U'
I'm working for 3 A's. Anybody with advice?
Original post by FutureDoctor14
I've just done my second practise exam and I'm still getting a 'U'
I'm working for 3 A's. Anybody with advice?


How do you study?
Original post by Hype en Ecosse
How do you study?



I haven't done much exam papers. My teacher goes I was just being an idiot and didn't read the question :frown:
Has anyone done Ocr coursework on lettuce leaf yet???
Hi, i am self studying Edexcel A level Biology this year ( I am doing all 6 units in may/june) but im not sure whether to choose SNAB or the Ann Fullick book. The SNAB book seems thinner than the Ann Fullick book. Which one is more concise, as in it doesn't ramble on about extra information that I won't need but also has all the points necessary. And should I make notes from the textbook or just reading it along with a revision guide plus past papers would be enough. Sorry if this question has been asked repeatedly, and thanks in advance for your help. :biggrin:
Hi guyss, so in my biology textbook it says this about triglycerides:

"They are hydrophobic because the charges on the molecule are evenly distributed around the molecule. This means that hydrogen bonds cannot form with water molecules, so the two types of molecule do not mix together easily" -

If anyone can explain that in more depth it would be greatly appreciated :/
Thank you!
Original post by Aleenaa
Hi guyss, so in my biology textbook it says this about triglycerides:

"They are hydrophobic because the charges on the molecule are evenly distributed around the molecule. This means that hydrogen bonds cannot form with water molecules, so the two types of molecule do not mix together easily" -

If anyone can explain that in more depth it would be greatly appreciated :/
Thank you!

Basically hydrophobic means non-polar. This might make more sense if you do chemistry as well. Basically, when atoms form a covalent bond some atoms are more electronegative (can pull the electrons in the bond towards them more easily). This means that the electrons are closer to one atom and that atom than the other and one atom becomes slightly negative and the other becomes slightly positive (electrons are negatively charged). When this happens the molecule is said to have a polar bond or is hydrophilic. A hydrophobic molecule is when the electrons are evenly shared between the atoms in the bond so the charge is even. Hydrophobic molecules cannot form hydrogen bonds as the positive and negative charge in the molecule is evenly distributed. Water is polar so can form bonds with other polar molecules. Does this make more sense now?
Original post by clearwater98
basically hydrophobic means non-polar. This might make more sense if you do chemistry as well. Basically, when atoms form a covalent bond some atoms are more electronegative (can pull the electrons in the bond towards them more easily). This means that the electrons are closer to one atom and that atom than the other and one atom becomes slightly negative and the other becomes slightly positive (electrons are negatively charged). When this happens the molecule is said to have a polar bond or is hydrophilic. A hydrophobic molecule is when the electrons are evenly shared between the atoms in the bond so the charge is even. Hydrophobic molecules cannot form hydrogen bonds as the positive and negative charge in the molecule is evenly distributed. Water is polar so can form bonds with other polar molecules. Does this make more sense now?


yaaass thank you! :d

Quick Reply

Latest