A2 Biol prac!

Cheers I think I'm alright without that paragraph but thanks for the offer! I agree, I think it's polar too - agree about the ethanol, I think we have used it in chemistry mixed with water to help not-very-polar things dissolve. I was kind of trying to make the point that it being soluble in alcohol didn't make it non-polar, but I guess I didn't put it across well!

good luck with your coursework
rosie

ps. Im from nottingham too

we were talking about the social or is that another rosie?
aside from a bit of tickling up, ive finished it!

no I think that must be another rosie.
mine is nearly there, but I have a vague memory of our teacher telling us we needed to include some kind of stats tests, so im trying to get those in!

rosie

i saw your post on T-tests but wasnt sure enough to reply to that particular thread! i think its suitable so long as your actual range is 7-30. i didnt see how you could use the chi squared.
im curious about what the practical could be; theyre usually connected (to the plan)

hi
i asked a friend who does Environmental Biology as his optional module (we do app. of genetics) and he said in th E.biology book it says you need 6 or more in each "set". So 6 it is.

I thought about using chi-squared for germination (I'm doing % of seeds germinated after 2 days - well, im using 100 seeds at a time, so it's really just count the seeds) but I'm not sure - I mean it's counted, not measured, which is discontinuous.. but as a %, %s should be continuous. I think.

So yeah, and use my expected values as the germination rates from the control.

D'you think that's not OK because the %s are continuous..? or are they discontinuous? have to admit, I'm not really sure!

last year (AS) the plan was not incredibly connected to the rest of the practical, iirc, the only "theme" in evidence was "biological molecules"!

Rosie

hi
i asked a friend who does Environmental Biology as his optional module (we do app. of genetics) and he said in th E.biology book it says you need 6 or more in each "set". So 6 it is.

I thought about using chi-squared for germination (I'm doing % of seeds germinated after 2 days - well, im using 100 seeds at a time, so it's really just count the seeds) but I'm not sure - I mean it's counted, not measured, which is discontinuous.. but as a %, %s should be continuous. I think.

So yeah, and use my expected values as the germination rates from the control.

D'you think that's not OK because the %s are continuous..? or are they discontinuous? have to admit, I'm not really sure!

last year (AS) the plan was not incredibly connected to the rest of the practical, iirc, the only "theme" in evidence was "biological molecules"!

Rosie

hmm, youve got me thinking now! im investigating % germination after 36 hours and mean growth after 72 hours (i think, and from the start). i was going to use pure water as my control and compare the [ABA] results to this. so i assumed i would have 2 means if you like so id use the T-test.

i rejected chi squared as you dont know what to expect when you add the ABA (we do app of genetics too and chi squared seemed to be more to do with epistasis and gene control etc etc, when you think you know what you're going to get). ive also got a worksheet with a similar problem to the one we're doing which uses the T-test.

im using 100 seeds for each concentration, then see the % germination growth, obviosuly %germination is small when concentration is high. im using 5 diff. concentration, but can someone tell me how to use T-test? chi-square is used to see if the results are random or not, i dont see the point of using chi-square, well may be im being stupid (ive only used that for genetics, so i cant link that with germination resulst)> i need to sort out how to find out germination % in teh first place.. can someone help? do i use the dry mass or something? coz if dry mass increases, then it means the seed has germinated, doesnt it?

hi rosie, no sorry my teacher has only told me the title, i had to copy the title of the board, he said he is not allow to tell me anymore, thats why i keep annoying everyone by asking so many bloody questions, you can understand how frustrated im ! can you tell me which test i should use? yes i can find out the germination % by counting, what about that T test you mentioned? is it good? and chi squared?

ive got in my notes that ABA is primarily transported in the phloem. in my plan i put that this suggests it is polar which is how i justified using water for my solvent to avoid the obvious propanone issue!!!
looked up ethanol. it said it can dissolve both polar and non polar solvents. if you need more info on that pm me and ill type the paragraph up for you

hi rae , can you type up the paragraph for me, please?? thanks! or use give me the web site so i can look up... im still confused about t test... which one is the best to use?