How was May/June 2017 Biology P52?

[Rizwan Javed]

So how did it go?

 

[Rizwan Javed]

I think it was pretty simple. Much easier that what we have been seeing in previous years.

 

[darks]

I think it was simple. I got 24 in hardy weinberg question I think it's not correct and 1 step short.. so 1 mark lost here. rest was not that tough. Gt will probably be around 20-22.

 

[saad rizwan]

wrote 28 for last answer. will they accept it?

 

[Sanaisnotanerd]

what topics were covered for variant 52?

 

[Syed Umar]

I got 29, too.

And as far as spearman correlation goes, yes, 0.88.

I am not sure about the cotton wool myself. Any guesses here?

Last part of Q1-- Narrow range. Only small concentrations tested.

Error-- Length. Should be standardized.

Overall, as it has been said, pretty simple, I felt.

 

[Syed Umar]

What safety precautions did you mention for the hypothesis?

 

[darks]

I got 29, too.

And as far as spearman correlation goes, yes, 0.88.

I am not sure about the cotton wool myself. Any guesses here?

Last part of Q1-- Narrow range. Only small concentrations tested.

Error-- Length. Should be standardized.

Overall, as it has been said, pretty simple, I felt.

length of what? i wrote about volume of caffeine solution added should be constant.

yes last part q.1 same as yours

spearman rank yes 0.88.

low risk experiment. Handle the (sea animal don't remember name) with care wear gloves if allergic to it.

in the 6 mark Q i think 2 marks for dilution method and concentrations. then, safety. const. temp. const. vol of caffeine solution added (i wrote 10 drops) const temp. control solution will be just water. measure heart rate 5 times under microscope, take mean. etc etc easy 6 marks i guess.

to make 100mgdm-3 caffeine solution i wrote " use 100cm3 capacity burette 5 times to add 500cm3 water into a beaker. Add one caffeine pill (50mg) to make 500cm3 of 100mgdm-3 solution.

in the hardy weinberg question i got to the point where we know that 24 out of 50 are heterozygous... will i get 2 marks??

 

[lolcat1337]

wasnt the hardy weinberg 17 cuz the population we had to take population as 35

 

[saad rizwan]

wasnt the hardy weinberg 17 cuz the population we had to take population as 35

nope population in 1997 was 60.

 

[saad rizwan]

I got 29, too.

And as far as spearman correlation goes, yes, 0.88.

I am not sure about the cotton wool myself. Any guesses here?

Last part of Q1-- Narrow range. Only small concentrations tested.

Error-- Length. Should be standardized.

Overall, as it has been said, pretty simple, I felt.

cotton wool: to prevent the Daphnia from moving

 

[darks]

nope population in 1997 was 60.

if i considered population as 50 (as stated in q) and not read from graph... can i get 2 marks for calculating, and using the formula all correctly but for 50 instead of 60...

 

[saad rizwan]

if i considered population as 50 (as stated in q) and not read from graph... can i get 2 marks for calculating, and using the formula all correctly but for 50 instead of 60...

they might give ecf so u could get 1-2 marks

 

[HELLNO]

51 anyone? How was it? I think it was a good paper!!

 

[AnonymousX9]

I got 29, too.

And as far as spearman correlation goes, yes, 0.88.

I am not sure about the cotton wool myself. Any guesses here?

Last part of Q1-- Narrow range. Only small concentrations tested.

Error-- Length. Should be standardized.

Overall, as it has been said, pretty simple, I felt.

"Length"? Of what?

What was the answer for last part of q2?

What answer did you guys write for why the conclusion isn't valid? I wrote because the experiment was carried out on crustaceans and not humans so no conclusions can be drawn about effect on humans.

 

[Syed Umar]

"Length"? Of what?

What was the answer for last part of q2?

What answer did you guys write for why the conclusion isn't valid? I wrote because the experiment was carried out on crustaceans and not humans so no conclusions can be drawn about effect on humans.

Yes, that is correct.

Length of the crustacean. They gave a range of 1-5mm I think, so different lengths might mean different metabolic rate etc.

 

[Syed Umar]

cotton wool: to prevent the Daphnia from moving

Ah. Right

 

[AnonymousX9]

I wrote difficulty in counting the number of heart beats and to reduce, repeat the experiment at each concentration of caffiene, identify and remove anamomalous values and then calculate a mean value for heart rate.

 

[darks]

I wrote that the volume of the caffeine solution should not be "few drops" it should be exactly 10 drops for each, the drops added using same type of dropper. Apply normal pressure on dropper each time to ensure each drop is of approx. equal volume. (My logic behind this was that if volume is higher or lower, molar quantity of caffeine will be different, so different affect on the crustacean for e.g drinking 1 cup of 50mg caffeine coffee is same as drinking two cups of 25mg caffeine coffee lol) idk maybe i am wrong.

 

[Panicgirl1516]

For paper 52- What did everybody write for question 2, the one on the plants?

There was stating the null hypothesis for the Spearmans rank
Working out the Spearmans rank

Which critical value did you guys use?
And what was your explanation for why there was more in higher mean January temperature?