Edexcel igcse biology may 2012 exam discussion

I really didn't want to put that because it seemed really harsh - wouldn't want to get on the examiner's bad side. That was a really vague question though.

I know i might be opening up a can of worms here because people were all very divided at my school, on the yeast respiration question, was temperature the independent variable and rate of CO2 production the dependent variable, thats what i put anyway?!

So what was your answer to that?

I know i might be opening up a can of worms here because people were all very divided at my school, on the yeast respiration question, was temperature the independent variable and rate of CO2 production the dependent variable, thats what i put anyway?!

I put that too because you could change the temperature but not the rate of CO2 production - that was up to the yeast!!

One the topic of the genetic question -

I didn't want to post about small people being unattractive (I thought that would be too offensive for the marksheme). I said that there is no selection pressure for the world's population to be small, and that Achondroplasia is a mutation that is at a selective disadvantage. Dunno if that's correct or would get full marks.

I think you would probably get a mark for that, I think I put it is a selective disadvantage, but I also put something about people people with Achondroplasia not living as long/ to full sexual maturity.

It was biological control over pesticides.

What do you think will come up friday...people here have mentioned breathing/lungs, ecology and GM
I think nitrogen cycle, making beer or cheese or yoghurt,
anything on the heart/blood/circulation?
how bout smoking?
osmosis?
transpiration?
(probably not those 2 as it is only 1 hr..)
inheritance(eg codominance)

I know i might be opening up a can of worms here because people were all very divided at my school, on the yeast respiration question, was temperature the independent variable and rate of CO2 production the dependent variable, thats what i put anyway?!

One the topic of the genetic question -

I didn't want to post about small people being unattractive (I thought that would be too offensive for the marksheme). I said that there is no selection pressure for the world's population to be small, and that Achondroplasia is a mutation that is at a selective disadvantage. Dunno if that's correct or would get full marks.

yeah it was weird lol
owell
What do you think will come up friday...people here have mentioned breathing/lungs, ecology and GM
I think nitrogen cycle, making beer or cheese or yoghurt,
anything on the heart/blood/circulation?
how bout smoking?
osmosis?
transpiration?
(probably not those 2 as it is only 1 hr..)
inheritance(eg codominance)
whaddya think...

This was posted from The Student Room's Android App

Hey guys!

So I found this guy on youtube who explains ALL the things you need to know from the specification:
http://www.youtube.com/user/click4biology/videos?view=1


And when they ask you to "describe an experiment you could do to find out......." you should use CORMS
Compare - Rang of value (independent variable)
Orgasm - species/size/age/sex...(controlled variable)
Replication - More than one reading
Measure - mass/ length/ units (dependent variable)
Same - temperature/ light intensity/ water (controlled variable)
THIS QUESTION COMES FOR 6 MARKS!

Hope it'll help

You didn't have to say "small people are unnattractive". You could say (and I did) that they "are less likely to find a mate and therefore pass on their genes". I think I said that it was therefore a selective disadvantage as well (word for word).

What ecology is on the syllabus?