Biology exam discussion - share revision tips in preparation for GCSE, A Level and other biology exams and discuss how they went afterwards.

Announcements Posted on
1. Re: AQA Biol A2 EMPA Megathread
(Original post by raveen789)
You lay it perpendicular because you are measuring the transition from a certain distance from the road
Cheating is a sin! you will not get far in life if you cheat. You will try so hard and get so far but in the end it wont even matter (I'm the living example of this) AQA will hunt you down and disqualify you from all their exams in the future. Lets end this the way it started, together Tom. May god if he exists be with you
2. Re: AQA Biol A2 EMPA Megathread
(Original post by sij01)
Cheating is a sin! you will not get far in life if you cheat. You will try so hard and get so far but in the end it wont even matter (I'm the living example of this) AQA will hunt you down and disqualify you from all their exams in the future. Lets end this the way it started, together Tom. May god if he exists be with you
3. Re: AQA Biol A2 EMPA Megathread
(Original post by sij01)
Cheating is a sin! you will not get far in life if you cheat. You will try so hard and get so far but in the end it wont even matter (I'm the living example of this) AQA will hunt you down and disqualify you from all their exams in the future. Lets end this the way it started, together Tom. May god if he exists be with you
mate, are you crazy? I was asking about a question in a past paper.
4. Re: AQA Biol A2 EMPA Megathread
That was weird!
5. Re: AQA Biol A2 EMPA Megathread

Oh dear task 3 was flipping awful.
Task 1 - for why standard deviation is more useful is useful than shortest and longest (range) isit because it takes into account all the data, shows variance from the mean, isn't affected by outliers as the shortest and longest may be anomolies/outliers.. ? May be extreme values.........? blabla..? Or is this wrong!?

4. something for the magnification then 6 for the actual size.?
Random sampling - assign seed number from 1 to 20 something or whatever it went to. Random number generator on calculator to get number.?
What is bias in selecting .? Choosing seeds due to personal choice and desired choice. Each seed hasnt got an equal chance of being selected due to the investigators choice of choosing them?
Then for the other 3 marker did you guys mention how smaller seeds travel further, longer seeds dont travel further, thus if the standar deviation is large there's more variation around the mean so there are differnet lengths, meaning that there will be a a large variation in the distances travelled?

I've failed!

And how you standardise the dropping thing.? :s ergh

Hope the boundaries arent high
Last edited by EffKayy; 17-05-2012 at 14:58.
6. Re: AQA Biol A2 EMPA Megathread
(Original post by EffKayy)

Oh dear task 3 was flipping awful.
Task 1 - for why standard deviation is more useful is useful than shortest and longest (range) isit because it takes into account all the data, shows variance from the mean, isn't affected by outliers as the shortest and longest may be anomolies/outliers.. ? May be extreme values.........? blabla..? Or is this wrong!?

4. something for the magnification then 6 for the actual size.?
Random sampling - assign seed number from 1 to 20 something or whatever it went to. Random number generator on calculator to get number.?
What is bias in selecting .? Choosing seeds due to personal choice and desired choice. Each seed hasnt got an equal chance of being selected due to the investigators choice of choosing them?
Then for the other 3 marker did you guys mention how smaller seeds travel further, longer seeds dont travel further, thus if the standar deviation is large there's more variation around the mean so there are differnet lengths, meaning that there will be a a large variation in the distances travelled?

I've failed!

And how you standardise the dropping thing.? :s ergh

Hope the boundaries arent high
more or less yes :-). the first part was 4 the second was 6 yeah :-)
7. Re: AQA Biol A2 EMPA Megathread
(Original post by asaaal)
more or less yes :-). the first part was 4 the second was 6 yeah :-)
eeerghhh hope ive done well

Task 2 I got no overlap - so rejected null hypothesis (which was that there will be no difference .. etc).
I used sample standard deviation though..? =/ People said this was wrong
Last edited by EffKayy; 17-05-2012 at 15:10.
8. Re: AQA Biol A2 EMPA Megathread
Man I forgot all of the questions and even what test I did xD
9. Re: AQA Biol A2 EMPA Megathread
How to standardise?
- Place seed on same point on ruler each time
- Same amount of force to release/ or no force
- Ruler adjusted right back so bendyness of ruler doesnt affect it (??????? total crap)
- Release them in the same direction.

Plumb line, how does it improve reliability

I talked about consistency in the measurements, more reliable as its just a measurement with ruler, so if two people did it they could get the same readings if the seed dispersed to the same area. - so no judgement required rather than you having to 'eyeball' where the drop point is, and therefore judge. So its more objective and not subjective. People may disagree from where the seed dropped .Also talked about how its accurate too.

Wind is a confounding variable, using more seeds reduce the effect
- No as the counfounding variable will still be there
but allows anomolies to be identified and therefore a reliable average to be calculated. But more seeds just means more representative..
Didn't know if it was saying more seeds dropped at the same time or just more seeds as in you repeat it more. But said if more seeds dropped at the same time, less surface area exposed so less affect of wind?
(This is wrong - so.. ? Dunno what they wanted)

Give ONE advantage of releasing 20 seeds at a time.
Less time consuming. Influenced by same wind speed.?
Give ONE disadvantage of releasing 20 seeds at a time.
Higher chance of error as the same seed can be measured twice . also they might land in the same area - so not really measuring what it wants to - "dispersal" ??

Give TWO ways in which vehicles help the dispersal of seeds.
Seeds get caught on vehicle wheels and travel greater distances before falling off i.e. dropped off at high speed or just washed off. Also talked about tyres - may trample over them - so doesnt allow dispersal. Also creates moving air - so allows dispersal. ..?????????

(By the way I typed this up after I did it which is why I remember it.. ahaha)
Last edited by EffKayy; 17-05-2012 at 17:04.

Step 2: Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank

this is what you'll be called on TSR

2. this can't be left blank

never shared and never spammed

3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. By completing the slider below you agree to The Student Room's terms & conditions and site rules

2. Slide the button to the right to create your account

You don't slide that way? No problem.

Last updated: May 17, 2012
Study resources