Edexcel A2 Biology Unit 5 (6BIO5) - 22/06/2011- OFFICIAL THREAD !

lol u're gone !
how does it make it black if its a hole ?! lol

Bah, you can barely call that synoptic, that's one of those 'science things' they try to drum into you in both Chemistry and Biology.
I was expecting a beautiful 6-marker on HIV/AIDS

But I totally anticipated the 'Give the structure of a triglyceride' one. I would've been really surprised if it hadn't come up.

I thought that! So was that an actual 'trick question' as they deny in the trade? Or just a crappy mistake on their part?

Was the answer one glycerol attached to 3 fatty acids?

i wrote one glycerol molecule attached to 3 fatty acids by ester linkages.
and then i drew a diagram.

I just put 80%.
Well I'm not sure, but either way a question like that shouldn't have been there! I think it might have been a crappy mistake, considering it was 2 marks.

What did you guys put for the 5 marker on spirometer practical. The question was something like "How would you use a spirometer trace to compare the difference in breathing rate and tidal volume of males and females?" I could only think of 3 things to say:
Measure length of peak for tidal volume;
Measure how many peaks over a certain time for breathing rate;
Get a sample of men and women to do it and compare their results;

Then I just explained what a spirometer practical was in the hopes I'd pick up some marks.

The question on mortality rates was terribly worded.
If the prevalence increased by 80%, that doesn't increase the mortality rate as a percentage because they're proportional. The mortality rate will still be 10-20%. The only way a 'percentage increase' method would have been valid, is if they gave you figures to compare the percentage increase of those that died before versus those after.

what did people put for the question about why the pupil appears to be black, i know it was a one marker, but it's bugging me

they didnt give you figures right but you had to just take the figure as "x" as you do in maths because the figure wasnt required, %age was required. i did like this :-

i got 16% :-

80% of pop was admitted so
80/100* X (X is number of young girls)

out of these 20% died :-
20/100(80/100*X)
cut out zeros and simplify it would come
16/100*X so 16% of X (young girls) died due to anorexia.

for the spirometer one , we had to talk about the trace right ? nothing about how it is done like mouthpeice and all ...?! rite ?!
well i wrote
obtain traces for both male and female
calibrate the chart beforehand to read off correct volume values
find tidal volume by measuring the height of the peak formed during rest
find the breathign rate by calculating the time for one breathe and then divide 60 by this answer.

and then i even drew a spirometer trace and labelled tidal volume and time for one breathe ..

will this be right ..?!

i posted my answer above see it !
i dont think they wanted to know anything about the experiment itself. they only asked about the traces.

they didnt give you figures right but you had to just take the figure as "x" as you do in maths because the figure wasnt required, %age was required. i did like this :-

i got 16% :-

80% of pop was admitted so
80/100* X (X is number of young girls)

out of these 20% died :-
20/100(80/100*X)
cut out zeros and simplify it would come
16/100*X so 16% of X (young girls) died due to anorexia.

It was 80% guys.

This is the information you were given. There was an 80% rise in the number of cases. Mortality rate is between 10 and 20%.

Think about it this way. If I flip a coin, the probability I get heads is 50%. If I flip that coin 4 times, the probability of getting a heads is still going to be 50%.

So in this case. If someone is admitted with anorexia, there is a 10-20% chance they will die. If 80% more people are admitted with anorexia, there is still a 10-20% chance they will die.

You can do it with numbers as well. Lets take 15% as the mortality rate. If you start with 100 people, 15 will die. After the 80% increase there are 180 people. 15% of that is 27.

15 to 27 is an 80% increase.

So it was a trick question then? Nearly everyone would have tripped up on it then.