[IFondledAGibbon]

Hi, i have my ISA theory mock tomorrow (AQA) and I need some help with some of the questions i think might come up. We basically investigated what effect light intensity has on photosynthesis. So we moved the light back from the plant recorded number of bubbles in a min.

If anyone could help me with any of the following questions that would be great.

1) Why did you repeat each distance 3 times?
2) What are any other limiting factors in the experiment?
3) Why did you invert the plant?
4) Why did you cut the stem?
5) Why did you cut the stem at a slant?
6) Why did you wait 5 mins before recording the number of bubbles in 1 min?

if anyone could think of any more I would also appreciate that.

thanks.

[goodboy4444]

(Original post by IFondledAGibbon)
Hi, i have my ISA theory mock tomorrow (AQA) and I need some help with some of the questions i think might come up. We basically investigated what effect light intensity has on photosynthesis. So we moved the light back from the plant recorded number of bubbles in a min.

If anyone could help me with any of the following questions that would be great.

1) Why did you repeat each distance 3 times?
2) What are any other limiting factors in the experiment?
3) Why did you invert the plant?
4) Why did you cut the stem?
5) Why did you cut the stem at a slant?
6) Why did you wait 5 mins before recording the number of bubbles in 1 min?

if anyone could think of any more I would also appreciate that.

thanks.

1) to make the experiment more reliable.
2)CO2,tempreture,humidity
3)
4)To let water into the plant
5)
6)Becuase it takes atleast 5 min for reaction to start.

They may all be wrong!!

Good luck!

[KDKDKD]

for number 6, it's because you have to allow 5 minutes for the plant to acclimatise to the surroundings.

[IFondledAGibbon]

(Original post by goodboy4444)
1) to make the experiment more reliable.
2)CO2,tempreture,humidity
3)
4)To let water into the plant
5)
6)Becuase it takes atleast 5 min for reaction to start.

They may all be wrong!!

Good luck!

Thanks, those answers woke my brain up a little.

(Original post by KDKDKD)
for number 6, it's because you have to allow 5 minutes for the plant to acclimatise to the surroundings.

Could you elaborate? what is the biological reason if you get me?

[KDKDKD]

when you first put it into the light, the plant will increase its rate of photosynthesis. By leaving it there for 5 or so minutes, it will increase it's rate to the optimum rate and stay constant. good enough explanation or should i get all technical on you? :P

[IFondledAGibbon]

OK so I’m thinking:
1) Increase reliability and to calculate a mean.
2) CO2 too low and stomata close. Temperature, to low enzymes e.g. ATP sythesase become inactive (kinetic theory). Too high they denature.
3) ???? Something to do with the stomata facing upwards?
4) Allow for uptake of water
5) Increased surface area for water uptake.
6) Allow plant to acclimatise (increase its rate upto the optimum and levels out) is that the saturation point?

Are these right?

[IFondledAGibbon]

(Original post by KDKDKD)
when you first put it into the light, the plant will increase its rate of photosynthesis. By leaving it there for 5 or so minutes, it will increase it's rate to the optimum rate and stay constant. good enough explanation or should i get all technical on you? :P

I'm thinking thats good enough for the exam. But you can explain further if you really want to :P Also when its reached the optimum, is that the saturation point?

[KDKDKD]

(Original post by IFondledAGibbon)
I'm thinking thats good enough for the exam. But you can explain further if you really want to :P Also when its reached the optimum, is that the saturation point?

umm im not too sure to be honest. i did a paper similar to yours, i also had a question on the second page asking what i used a certain chemical for. i just remember it was used as a source of co2. sorry i can't be much more of a help

[IFondledAGibbon]

(Original post by KDKDKD)
umm im not too sure to be honest. i did a paper similar to yours, i also had a question on the second page asking what i used a certain chemical for. i just remember it was used as a source of co2. sorry i can't be much more of a help

ah yeah I forgot about that! Cheers for all the help.

[brainpopper]

(Original post by IFondledAGibbon)
Hi, i have my ISA theory mock tomorrow (AQA) and I need some help with some of the questions i think might come up. We basically investigated what effect light intensity has on photosynthesis. So we moved the light back from the plant recorded number of bubbles in a min.

If anyone could help me with any of the following questions that would be great.

1) Why did you repeat each distance 3 times?
2) What are any other limiting factors in the experiment?
3) Why did you invert the plant?
4) Why did you cut the stem?
5) Why did you cut the stem at a slant?
6) Why did you wait 5 mins before recording the number of bubbles in 1 min?

if anyone could think of any more I would also appreciate that.

thanks.

i've got my isa exam tommorow on the same topic as a mock, what type of questions came up in your exam?

[IFondledAGibbon]

(Original post by brainpopper)
i've got my isa exam tommorow on the same topic as a mock, what type of questions came up in your exam?

Quite a few of those if my memory serves me correctly (it probably doesn't considering it was 2 years ago!).

I used to just go through the method sheet and ask myself why we did each step.

[SabeeahJaved]

(Original post by KDKDKD)
for number 6, it's because you have to allow 5 minutes for the plant to acclimatise to the surroundings.

svffvavv