Competition - post a photo you've taken of nature >>

A2 Biology Unit 6 ~ 16th May 2012

Scroll to see replies

hmm i think it has something to do with ''plant growth'' so i think a mark will be given for saying the plant growth will be inhibited and the other explaining why..
i wrote that it will inhibit the growth of the plants specially the leaves increasing their mass , making it impossible for the stem to withstand the weight so it breaks, and due to insufficient minerals and due to loss of other minerals and the lack of photosynthetic parts the plant dies.... im not sure if thats correct but i really dont like to leave a question unanswered D:

but thats not even in our course, not even slightly !!!!! edexcels a troll !!!!

Reply 281

Erycuna

Original post by iesians

but thats not even in our course, not even slightly !!!!! edexcels a troll !!!!

i know :/
but if you thought about it, we pass on the expense of other people failing, so they have to do such a thing because a way below average student could get a 60/60 if it was only dependent on memorizing , that being said, im against all of that :smile:

Reply 282

laugh123

by the way , for any variables that need to be controlled , how they are controlled and how would they affect ? what did you mention ?

Reply 283

Erycuna

Original post by laugh123

by the way , for any variables that need to be controlled , how they are controlled and how would they affect ? what did you mention ?

well i wrote the water availability in the soil ->adding volumes of water by a beaker/pipette etc.. ->needed for photosynthesis and other chemical reactions in the plant

Reply 284

iesians

Original post by Erycuna

well i wrote the water availability in the soil ->adding volumes of water by a beaker/pipette etc.. ->needed for photosynthesis and other chemical reactions in the plant

u needed to state how will it affect the RESULT ! u just listed its importance and functions...

well i said, light intensity --> expose to weedkiller during same time of day ----> high light intensity will increase photosynthesis and growth, and so we will be unsure if growth is due to light intensity or resistence to the weedkiller.

Reply 285

laugh123

Gosh I feel so horrible ... I am 100% sure im failing this exam ! I dont have any of the sophisticated answers you mentioned above FML!! What are the grade boundaries

Reply 286

Erycuna

Original post by iesians

i did i said without it wont photosynthesis -> no growth-> no food/sugar -> the weed will die eventually etc... i was just trying to sum it up when i said it here :P

Reply 287

iesians

Original post by Erycuna

i did i said without it wont photosynthesis -> no growth-> no food/sugar -> the weed will die eventually etc... i was just trying to sum it up when i said it here :P

oh ok np !! :smile:

i just want an A !!!!!!!!!!!!!!! lol

Reply 288

Erycuna

Original post by iesians

oh ok np !! :smile:

i just want an A !!!!!!!!!!!!!!! lol

amen!!

Reply 289

aqua05

Ok guys what did you write for the limitations fr the every last quest.. Q3 c...
I wrote..the volume of the bacteria culture being put in the petridish wouldn't be equal..as some of it will be left in the pipette
2. The area of the clear zone wouldn't be exactly accurate..its just going to be an estimate..as I said area of the clear zone is uneven
3. The bacteria may not be evenly distributed in the petridish in all experiments thus affecting results obtained

Is this correct?

Reply 290

aqua05

For Q1 I wrote... this is brief to what I wrote..
Carry out exp on a 500m2 field growing cereal plants.. measure %cover by using a line transect..for this method, use quadrant (0.25m2) which is subdivided into to smaller squares for precision... 1m distance between each quadrant.. count the no of squares which has weeds.. calculate % cover for each quadrant. Record. Then after the experiment.. calculate the mean % cover of the whole field... then apply selective weed killer uniformly throughout the field.. then after 3 weeks repeat the entire experiment.. calculate the mean %cover.. &compare... repeat the entire exp for at least 5 times b4 coming into a conclusion

Reply 291

kitriviolet

according to my limited understanding IAA stimulates cell elongation by osmosis? :P lemme look it up...

Original post by iesians

i dont see a connection...i wrote IAA causes cell walls to become stretchy and elastic and thus water will rush into cell and cell will rupture due to osmotic shock ! isnt that what IAA does.....

Reply 292

iesians

Original post by aqua05

i wrote completely different ! :-

-possible risk of contamination
-many factord affect bacterial growth such as temperature nutrient content etc, and its difficult to control all of that
-placing the discs evenly is arduous
-i said i will be using graph paper to estimate area of clear zones and counting all squares is hard and inaccurate...!!!

i dunno whats gonna happen with me !!!! :confused:

Reply 293

iesians

Original post by kitriviolet

according to my limited understanding IAA stimulates cell elongation by osmosis? :P lemme look it up...

well, it actually does. :wink:

but in weedkiller there may be some other kind of IAA which makes the walls so elastic that osmosis results in lysis of the cell ........see what i did there ! OMG i wanna die now !!!! i just want it to beh correct ARRGGHHH i hate edexcel !

Reply 294

iesians

i found this on a site(http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/A/Auxin.html)

Why should a synthetic auxin kill the plant? It turns out that the auxin influx transporter works fine for 2,4-D, but that 2,4-D cannot leave the cell through the efflux transporters. Perhaps it is the resulting accumulation of 2,4-D within the cell that kills it.

how the **** were we supposed to know that ??! im gnna sue edexcel..!!

Reply 295

kitriviolet

yep i did hear that some auxins do work by acidifying the cellulose making hydrogen bonds break? :P but the walls being elastic may not always cause water to move in, it really does depend on the water potential..:P good luck! i guess edexcel is a bit nicer than cambridge, thats all i can say xd

Original post by iesians

well, it actually does. :wink: