Advice on how to revise of A level OCR A biologyWatch
If I have one piece of advice for Alevel biology it's to do as many past papers as you can as they tend to reuse questions or have questions very similar to each other. If you're struggling to do the questions it'd benefit learning how the mark schemes work for your specific exam board as it'll give you a better idea of how to hit each point in each question.
Hope this helps,
UoP rep - Ben
[excerpt from one of my posts]:-
Biology is a very logical and normally easily predictable subject, invented by the Tetragammaton himself (who actually I do not believe in!).
My advice to students of biology (irrespective of the exam board) is to read the Q carefully twice, think about the wording, and try to work out what the examiner is looking for (very difficult sometimes!) - the ways to do this are:
1. Look at the words used: "Describe" means "what can you see or observe directly?" - if it is a graph you are looking at:-
a) what is the overall trend?
b) is the graph bottom left to top right or other way round i.e. do the dependent values (y axis) increase or decrease, respectively, as the independent values (x axis) increase?
c) how steep is this rise or fall?
d) What x value does it start at?
e) what x value does it end at?
f) does it level out at any point?
g) if yes, where?
h) is there any change in direction anywhere?
i) If so, which way?
h) does the line go though the origin?
2. "Explain" means "Why?"
a) try and work out reasons for any/all of the points in part  or for the particular point asked?
b) think logically what effect the values of x could have ion the values of y. e.g. Why does a graph of enzyme action plotting product conc (y axis) against time (x axis) level out after a certain time and why is this time different if the initial substrate concentration is different? If the substrate is all used up, of course no more product can be formed - less substrate to start with = levels out at a lower y axis height = less product formed at equilibrium. If a different curve is shown for a higher temperature e.g. at 40 degrees, why does it level out at the same height as the lower temp curve but earlier? Yes, because enzyme action is speeded up by faster collisions, so more substrate/active site interactions; reaches peak earlier but at same height as lower temp = same final amount of product - If temp = 65 degrees, say, OK because the denaturation of the enzyme by heat means that after a certain period there is no more active enzyme left to collide with and act on further molecules of substrate, the highest point reached is lower (on y axis) because it is likely some substrate will never be converted to product as there is no more viable enzyme remaining.
c) Fo a table of data, first, as with a graph, have a quick scan of the data (30-40 secs) to quickly glimpse what the variables are and how they have been measured from the description of the experiment. Then take a glance at the Qs followed by a deeper look at the data then try to work out the points mentioned in  and  a) and  b) above.
d) The last part is usually a suggest Q where the mark scheme has a wider scope, and if what you say is correctly using the data AND makes logical sense AND is relevant to the Q, you will get your mark(s).
3. The number of marks assigned to each part of the Q (always given these days) usually tells you how many different correct and relevant points/ideas/factors/reasons/observations you need to gain full marks (the mrk scheme will almost always have more than the assigned no. of marks). It is a good idea to put down one more of these ideas/points etc. than the number of marks assigned to the Q as an insurance measure, as long as whatever you put down is not incorrect. If it is incorrect, you may be penalized; however, if it is irrelevant but correct, you will get zero for that item - nothing gained, nothing lost!
Good luck and if you have any specific problems, feel free to post them here!
M [specialist biology tutor]