LC Biology Question-Mandatory Practicals

oryxandcrake

I keep coming across this question in the exam papers in relation to the alcohol fermentation experiment:

Why as the apparatus sterilised before the investigation?

WHY INDEED.

Can anybody answer this?

Acciaccatura

To kill any micro-organisms that may be already present and interfere with the respiration of yeast cells.

I could be wrong now, but it'd be something along those lines, given that yeast is a micro-organism.

oryxandcrake

That sounds about right! Thanks.

Acciaccatura

No bother at all What year was that paper?

oryxandcrake

My teacher printed out some section A and B questions from past mock papers. It was in 2 of them. I think these ones are a lot trickier than the real ones though! (I hope she was just trying to scare us into studying more :S)

Acciaccatura

Ah, don't worry about it, as long you write something that makes some sense you'll get some marks Yeah, I find that too, don't panic too much!

hfallada

Just do all the past papers for the praticals. They aren't that hard. But my class was warned don't expect 1 experiment per question. Except a mixture like the immolisation, then test for sugars and then something else one after an other in the same question. But don't panic and look at it again.

oryxandcrake

Yeah, I kind of noticed a shift from the 'experiment per question' format in the last couple of years. These mock papers don't really reflect the way they've been doing them recently. They only use one experiment and ask more obscure questions.