How was Biology Paper 5?

[honeycoveredcookie]

Did everyone find it easy, or was it just me?

Discuss your answers so that we can cross check to see what was right and what was wrong.
YAY.

 

[shinypeachdrop]

Epic.

 

[honeycoveredcookie]

Thank goodness there were no messed up calculations. xD

 

[shinypeachdrop]

Ai know rait? Btw it's Ditz.

 

[samy]

so easyyy.....though the investigation needed alot of thinking.!!!

 

[mury456]

gave papr 52 ... investigation ws tough ... oocyte qs ws juz gvin marks away

the A threshold is probli gona be above 20 ...

bst of luck wd da resltz all ...
cheers

 

[ParanoidAleveler]

i guess the paper was okay.
LOL i wrote like soo much for the question! it was all over the place.

In the second question, was it a t-test or a chi-squared test? :unknown:

 

[samy]

t-test..as continuos data and cmparison of means.!!

 

[ParanoidAleveler]

but but but wasnt there an overlap of the values?

 

[honeycoveredcookie]

Oh gosh. I said that it was chi - test.

Yeah - and my first question was all over.

What were the units of rate? I said mm per second.
And the variables to be controlled - the size of the droplets and the dimensions of the plant tissue!

Yeah the threshold is probably gonna be insanely high. Probably 24 or something.

And yeah - there WAS an overlap in values.

 

[ParanoidAleveler]

i wrote chi too! cuz i thought in a t-test the data isnt supposed to overlap =S

lol for the rate unit i wrote kg m^-3 s^-1 (totally made it up)

i said the time for osmosis should be controlled and the volume of the sucrose solution in which the drop moves =/


im so so so stupid. i drew freaking ANIMAL cells in the microscope part -__-

 

[samy]

but as far as i think it wax a comparison of mean and normal distribution of data..it should b t-test..!!!

for the first question for constant variable i aslso wrote temperature as in the next parts it wax asked that y to control it..so high temp will damage the membrane of plant tissue...

my investgiation was all over even on the seond page a lil bit!

 

[samy]

i wrote chi too! cuz i thought in a t-test the data isnt supposed to overlap =S

lol for the rate unit i wrote kg m^-3 s^-1 (totally made it up)

i said the time for osmosis should be controlled and the volume of the sucrose solution in which the drop moves =/


im so so so stupid. i drew freaking ANIMAL cells in the microscope part -__-

for the rate i wrote cms-1...

though cm is not a SI unit but the test cannot be in m....however v can convert it in m later...
n didnt wrote mm cox it would be diffeicut to measure cox of reaction error!

 

[ParanoidAleveler]

i guess.. but it was density / time right?

mannn. the t-test question was 1 mark yea?

 

[MukeshG93]

It was boring.. :/ The stuff I wrote in 1 (a) had to be repeated in 1 (b) because I had mentioned the variables, how to control/measure them, the constants, how to control them and what not. I messed up the rate, I wrote cm-3s-1 and I completely ignored the fact that we can measure the movement of the droplet because it freaking diffuses throughout the sucrose solution and we can see how far the die has gotten (in short, I am an idiot). Everything else went fine. The test to be used is a t-test because there are no discrete data for a single concentration sample, just the mean and standard error (which can be used to calculate the standard deviation) and everything else was just cake. The threshold will be over the top, around 22 or 23 unless CIE pulls something hard on us and shows us something that we ALL messed up on (which is very possible; how many of you had figured out why the degrees of freedom where 38 in that one question?). I just hope everything goes fine, P4 is remaining, that'll back everything up.

 

[SilentAssassin]

It was definitely a t-test... there was continuous variation... data collected was not discrete... plus I don't think we see standard error "Sm" in chi-squared test... not sure about that... but yeah, it was a t-test...

mm per second is probably right...

Expecting something around a 24-25...

But GT will probably not exceed 22... it seems easy at first go... but many candidates end up making silly mistakes... let's hope for the best...

 

[MukeshG93]

It was definitely a t-test... there was continuous variation... data collected was not discrete... plus I don't think we see standard error "Sm" in chi-squared test... not sure about that... but yeah, it was a t-test...

mm per second is probably right...

Expecting something around a 24-25...

But GT will probably not exceed 22... it seems easy at first go... but many candidates end up making silly mistakes... let's hope for the best...

True that. Let's hope for the best. Although I feel kinda bad that I prepared so damn hard but in the end it didn't really matter. Meh... frustrated that I did well (LOL, I am crazy!)

 

[honeycoveredcookie]

It was boring.. :/ The stuff I wrote in 1 (a) had to be repeated in 1 (b) because I had mentioned the variables, how to control/measure them, the constants, how to control them and what not. I messed up the rate, I wrote cm-3s-1 and I completely ignored the fact that we can measure the movement of the droplet because it freaking diffuses throughout the sucrose solution and we can see how far the die has gotten (in short, I am an idiot). Everything else went fine. The test to be used is a t-test because there are no discrete data for a single concentration sample, just the mean and standard error (which can be used to calculate the standard deviation) and everything else was just cake. The threshold will be over the top, around 22 or 23 unless CIE pulls something hard on us and shows us something that we ALL messed up on (which is very possible; how many of you had figured out why the degrees of freedom where 38 in that one question?). I just hope everything goes fine, P4 is remaining, that'll back everything up.

Yeah - even I repeated stuff that I wrote in my experiment in the next page when the asked about it. :/
I messed up the t - test thing and wrote chi square test.

I measured the time taken for one drop to sink completely to the bottom, or to move completely to the top. :/
And i thought that rate should be mm per second because it would be more accurate than cm per second.

I didn't draw any cell because I thought the data alone was enough. The two words I used to describe the cells were "turgid" and "flaccid."

Oh and yeah, why did the oocytes have to be primary? I said that all needed to be at the same starting point for accurate comparison of meosis. Don't think that's right though.

 

[honeycoveredcookie]

Oh, and one more thing.
It asked us how we can determine the water potential of the plant tissue.

I said that we should keep them all in distilled water for around 20 minutes, and then look at the under the microscope to see whether they're all uniformly turgid.
At the start of my experiment too, I mentioned that all the plant tissues must be first kept in distilled water for around 15 minutes so that they have similar water potential so that the results are accurate when measuring the water potential for sucrose.

 

[MukeshG93]

Oh, and one more thing.
It asked us how we can determine the water potential of the plant tissue.

I said that we should keep them all in distilled water for around 20 minutes, and then look at the under the microscope to see whether they're all uniformly turgid.
At the start of my experiment too, I mentioned that all the plant tissues must be first kept in distilled water for around 15 minutes so that they have similar water potential so that the results are accurate when measuring the water potential for sucrose.

You'll get points for mentioning the need to equilibrate the plant tissues to the same water potential, I didn't mention that. As for the oocytes. The hypothesis was testing the effect of the activator compound on the maturation of immature oocytes and in order to keep them immature, you cannot let them move on to the secondary stage, else meiosis would start and using the compound wouldn't matter much.

It didn't ask us how to determine the water potential, it asked us how to estimate it, which gives a clearly different meaning. On the graph, there will be a point where the line cuts the x-axis, which would mean the diffusion of the droplet is zero at that point. That point would correspond to a certain sucrose concentration and it would mean the water potential of the sucrose solution and the plant tissue are the same at that point. So, we can use that particular concentration of sucrose and find its water potential to estimate the water potential of the plant tissue.

Also, the specific term is not flaccid, it is Plasmolysed