A2 Biol prac!

is ne1 else doing the OCR A2 Biol prac... on germination and stuff? does ANYONE know wat to do 4 it? we have 23 give it nxt fri...its sorta got 2 do with tomato seeds and stuff, cany you tell me where u can find info on germintation from the internet thats actaully related to tomato seeds and how they grow and stuff??
than xx

Reply 1

Golden Maverick

4

We were given the planning yesterday and we have to do some prelim work on monday. The idea is that the chemicals in the tomatoes (possibly abscisic acid ABA) inhibits the germination of the seeds so I think we're meant to extract the chemicals somehow and then give it to the seeds in a series of concentrations.

There's loads of info on germination if you type 'germination' into google.

Reply 2

hollyxxx

OP

hey, thanx.
i asked my teacher on mon, and he xplained it 2 me. we're doing ou rpre-lim 2moro. i sorta understand now, we have to take the aba outta the tomatoes....dunno how, using the solvents?? and then, we have 2 use those on cress seeds to see if it inhibtis the growth of those? hope i'm right!! thanx 4 replying neway1! xx

Reply 3

hollyxxx

OP

hey im doin d same thing is im a bit stuck as to what ta write 4 d preliminary coz we dint do one wer meant to mek up d results..did u do ur preliminary using propanone and water? if so which one r u using?
n wat do i write 4 d preliminary?

ne help wud be appreciated

maybe it would b nice if u spoke proper english? then i could understand wat the heck u r saying.

Reply 4

Miss Nakhrey

hollyxxx

hey im doin d same thing is im a bit stuck as to what ta write 4 d preliminary coz we dint do one wer meant to mek up d results..did u do ur preliminary using propanone and water? if so which one r u using?
n wat do i write 4 d preliminary?

ne help wud be appreciated

maybe it would b nice if u spoke proper english? then i could understand wat the heck u r saying.

THANK YOU SOO MUCH FOR YOUR TIME!!!!
MUCH APPRECIATED

PS. IS THAT PROPER ENOUGH FOR YOU!!!!!!!

Reply 5

diddy girl

so does anyone have a clue what to do!!!
im unsure if its the enzymes or the inhibiters that i should be looking at. I thought it was about the enzymes but now i think it may be about the acid! arghhhhhh can anyone help me?? i have 3days lefft!!!

Reply 6

diddy girl

someone please help1!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Reply 7

hollyxxx

OP

hey diddy girl
yay, u speak norm english!! hehe
erm, 4 the scientific knowledge, u just gotta write about gibberelins and how ABA is the inhibitor. putting in a picture of a seed wud b good as well (a cross-section thing, not a photo of a seed hehe)
erm, its maximum 1000words, so dont have 2 go over the top.
i think its more about the inhibitors really, as thats the aim of the investigation... u doin OCR yeh? i mean, the enzymes r part of it, and u shud mention them, but mainly how bout the inhibtion stuff
erm....thats it. bt yeh...more on the inhibtion stuff really
hope this helps, most probably doesnt cos ive just written aload of crap of the top of my head
Holly x

P.S **IVE LOST THE COVER SHEET!!**

Reply 8

Wilsoncswai

dear BIOLOGISTSSSS
to everyone- the whole bloody world is doing the same coursework and I need MORE MORE MORE ideas...... does anyone know how to write up the method? how to get those ABA and gibberelin out of tomato? should we extract skin, juice, seeds and everything? what other things inhibit growth of cress seeds? we are given polar and non-polar solvent yea? what polar solvents? why propanone? do we use both? can please someone intelligent help me coz im real stupid!
email me if you want: [email protected] THanks OCR buddy!

Reply 9

hollyxxx

OP

well, if ure so stuck u shud really ask ure teacher 4 help. when do u have 2 give in ure cw, we had 2 give it in last mon!
k, neway, u get the aba and stuff from the tomato by putting the whole tomato (skin included) into a blender, and mix mix mix! and then u know the cress seeds? well, place them onto a paper towel thats inside a petri dish, and pour the tomato juice onto them, at difference concentrations. u make the diff concentrations with water. so, for example, u use 5cm of just water, 4cm water and1 cm tomato extract, up to just 5cm of just tomato extract etc.
erm, then u leave it in the propogater and measure the root length with ruler or graticule. mine didnt grow until after 48hrs, bt i only measure them after 72hrs cos i was a lazy arse. i used a ruler so that in my alternatives i cud write that i shud have used a graticule as that wud have been more accurate. i dunno bout the solvents, i know thats on the cover sheet, but even my teacher didnt know why we need the polar/non-polar sovlents, mayb sum1 can tell us??????
hope that helps
xxx

Reply 10

Wilsoncswai

thanks so much hollyxxx- but putting the whole tomato in is going to affect the cress seeds by all sorts of germination inhibitors. im sure there are more than one (ABA), so may be those solvents are used to separate those germination inhibitors ? how do you measure root length coz its going to be TINY, unlike girls like you have beautiful small fingers, i got big huge ones, so dont think i can measure root length... any other ways? can you remember what solvent you used ? i think its propanol for non-polar solvent.... is it water for polar??? thanks so much

Reply 11

hollyxxx

OP

lol. i like the "small beautiful fingers" part. hehe.
erm, if the roots are long enough u use a ruler, if not a graticule. i used a ruler, so that i can write up in my improvements to use a graticule in my main experiment so it wud be more accurate, but its up 2 u. u can also measure the roots under a microscope, but my teacher sed thats a waste of time.
yeh, thats a gd idea bout the solvents thing, i didnt do nething like that, my teacher sed dont bother. yep, water is the polar solvent.
xx

Reply 12

Wilsoncswai

did you use the whole tomato and squash it and squuze juice out? or did you separate them into different parts, i.e. only skin, only juice, only juice e.t.c.? how many tomato did you use? its very vagged- please explain method more in details if you can? sorry to ask you so many questiosn, i know im annoying, hehe, thzzzz

Reply 13

hollyxxx

OP

u put the WHOLE tomato INCLUDING the skin, seeds, flesh, EVERYTHING, inside a blender and mix it all together. my teacher did it for us, he put 3 tomatoes in cos he did it for the whole class. if ure doing it seperatley ull only need 1 tomato.

this is my method:

Ø Place 10 seeds of the cress seeds onto a paper towel that’s inside the petri dish
Ø Measure the concentration of the tomato extract you want on each petri dish.
Ø Pour the tomato extract onto the petri dishes, to soak onto the paper towels, and then leave in the propagator.
Ø Measure the root lengths (if any) after 24hrs, 48hrs and 72hrs with a graticule or a ruler, depending on the size of the roots.

thats it. hope it helps, ask questions if u still dont understand, bt mayb its just me not explaining properly. gd luck!! xxx

Reply 14

Wilsoncswai

hey. thanks..... can you tell me why you are using paper towels but not cotton wool, paper towels are thin... how much solution are you putting into the pertri dishes? did you drowned the seeds? did you find out the dry mass of cress seeds ?

Reply 15

rae

im doing the same one. if you're given water and propanone surely you have to use them?
ive got that ABA is ish water soluble and it can be found by grinding up that jelly stuff surrounding the seeds with the seeds - if ABA inhibits germination, then its got to be in the seeds/surrounding tissue. prelims showed pure propanone kills seeds, water makes them germinate and anything with tomato extract slows germination and growth.
so, my plan is to change the concontration of ABA by adding it to different volumes of water.
gibberelins, auxins and cytokinins apparently have the opposite effect to ABA and besides, ABA is the only one related directly to inhibition.

also youre supposed to make synoptic links etc, so what have u put for that? and does anyone know a good site to get a cross section of a seed?

Reply 16

rae

Wilsoncswai

hey. thanks..... can you tell me why you are using paper towels but not cotton wool, paper towels are thin... how much solution are you putting into the pertri dishes? did you drowned the seeds? did you find out the dry mass of cress seeds ?

we were told to use filter paper as the seeds often get trapped in cotton wool

dont drown the seeds because otherwise youll get anaerobic respiration and u want it all standard with aerobic (if less ATP is made then surely growth etc will be limited by a lack of energy?) remember that water logging stuff in the ecology section and last years' work.

Reply 17

Wilsoncswai

hi, yea thanks. i know ABA is the stress hormone, but doesnt gibberein do anything? it stimulates cell elongation (ie roots), and it stimulates maltose which breaks down the startch foodstore in endosperm doesnt it? are you sure ABA is the only one? coz title says 'extracts from tomato fruits' and could be anythinng, skin, juice e.t.c. are you just sqeezing jelly stuff around the tomato seeds. sounds very logical that ABA is around the seeds but are you extracting anything else? ? also,. how exactly do you get those jelly stuff out, do you use propanone? why are they giving use nonpolar solvent if ABA is polar? how do we use propanone?

thanks so much, sorry to ask you so many Qs!!! THANKSSSSS

Reply 18

rae

Wilsoncswai

hi, yea thanks. i know ABA is the stress hormone, but doesnt gibberein do anything? it stimulates cell elongation (ie roots), and it stimulates maltose which breaks down the startch foodstore in endosperm doesnt it? are you sure ABA is the only one? coz title says 'extracts from tomato fruits' and could be anythinng, skin, juice e.t.c. are you just sqeezing jelly stuff around the tomato seeds. sounds very logical that ABA is around the seeds but are you extracting anything else? ? also,. how exactly do you get those jelly stuff out, do you use propanone? why are they giving use nonpolar solvent if ABA is polar? how do we use propanone?

thanks so much, sorry to ask you so many Qs!!! THANKSSSSS

i think you can choose to do it from any angle - im pretending ive never heard anything about gibberelins to make life easier! im taking the jelly and seeds and grinding them in a pestle and mortar to release the ABA (hopefully), then adding the appropriate amount of water to it. you can scoop the jelly out.
about the propanone - propanone on its own kills the seeds and water is needed for germination. therefore you'd need water, propanone and extract. if they grew/didn't grow, how can you tell which one is responsible?
i guess they give you water and propanone in case you want to focus on a different regulator?

Reply 19

Wilsoncswai

so are you saying that the propanone is used to kill the seeds in tomato? why kill the seeds? coz i believe propanone is an inhibitor itself- i.e. it wouldnt allow cress seeds to germinate in propanone. are you doing the dry mass? measuring dry mass ? if yes how do you do it?

A2 Biol prac!

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