How was Biology Paper 42 MAY/JUNE 2017?

[MariaKhan243]

2004 base pairs.
I don't remember a blood cell question... can you give more detail...?

Wasnt it 1002 cuz 2004 is no of bases we divide by 2 to get base pairs?
Which type of blood cell should be looked at in a blood sample to get allele?

 

[darks]

Wasnt it 1002 cuz 2004 is no of bases we divide by 2 to get base pairs?
Which type of blood cell should be looked at in a blood sample to get allele?

as far as i think.. 2004 was the number of "pairs" i was getting.. i multiplied the given number by 3. Those 2004 exist as pairs in the DNA.

 

[Paranauts]

Wasnt it 1002 cuz 2004 is no of bases we divide by 2 to get base pairs?
Which type of blood cell should be looked at in a blood sample to get allele?

There were 668 amino acids, so that means they were coded by 2004 bases on the mRNA (since one amino acid is coded by 3 bases) and since there were 2004 bases on the mRNA, that means 2004 bases on the sense strand of DNA (the strand that gets transcripted). Which means that there were 2004 base pairs in the DNA because the sense strand is bonded to the other strand which must also have 2004 bases.

 

[darks]

There were 668 amino acids, so that means they were coded by 2004 bases on the mRNA (since one amino acid is coded by 3 bases) and since there were 2004 bases on the mRNA, that means 2004 bases on the sense strand of DNA (the strand that gets transcripted). Which means that there were 2004 base pairs in the DNA because the sense strand is bonded to the other strand which must also have 2004 bases.

You explained so much better than me!

 

[darks]

Guys there was another question in the Simpsons index of diversity question... I wrote the details of Random Sampling in high and low land as the answer.. am i correct?

 

[HELLNO]

Guys there was another question in the Simpsons index of diversity question... I wrote the details of Random Sampling in high and low land as the answer.. am i correct?

3 easy votes

 

[Sufia_at]

What was the number of base pairs? And for the 1st qs acetate was already combined with CoA = acetyl CoA they asked "P + Acetyl CoA" so obviously its pyruvate and not acetate as acetate is already combind with CoA

And what blood cell do we look at in a sample?

I wrote white blood cell because it has nucleus to get DNA from.

 

[AnonymousX9]

I wrote line transect systematic sampling for the 4 mark question. Is it correct?

 

[darks]

I wrote line transect systematic sampling for the 4 mark question. Is it correct?

now you are scaring me i wrote random sampling on each type of land.. High and low. and then compare.
i wrote random as it was not a gradual increase from low to high. in which case we would use systematic sampling. It was either high OR low. No in between.

 

[Saly Elkady]

Most of the students in my center found variant 41 to be difficult and lengthy so i think the boundary will be similar to v42 because v41 didn't have much repetition and had a lot of analysis and just general knowledge. And for people who did v41, what did you guys answer for why algae photosynthesizes faster in polyp than when its free?

Because they provide them with CO2 which is needed for light independent reaction so when they are in excess the rate of photosynthesis increases ( I wrote a lot and explained in more details but this was mainly the idea and I'm not sure if it's right )

 

[Metallic9896]

I and a couple of others in my centre completely lost that 1 mark in p42 for the base pairs for no reason at all. I was panicking so hard I kept dividing 668 by 3 instead of multiplying it. Only when I was on my way back did it occur to me what blunder I had made. XD Anyway, for the high and low lands I wrote random sampling and then percentage cover and an abundance scale to compare the density etc. of the different species (of plants I think? Forgot what the question asked). And B-lymphocyte since it can divide by mitosis and thus that allele would be significant in it since it has to do with tumors and tumors are uncontrolled mitosis as well etc. But I know quite a few who simply wrote white blood cell so should be cool.

 

[AnonymousX9]

Wouldn't an interrupted belt transect be correct as well? I wrote about frame quadrats at regular intervals along the line and percentage cover using Braun Blaunquet scale... will I at least get 2/4?

 

[darks]

Wouldn't an interrupted belt transect be correct as well? I wrote about frame quadrats at regular intervals along the line and percentage cover using Braun Blaunquet scale... will I at least get 2/4?

Not sure to be honest. I can see one mark for writing about quadrats, that too if you wrote of "equal sizes". It really depends on how you explained it. If you said to compare high land with low land, then maybe more marks...

 

[darks]

i don't even remember a white blood cell question : p maybe i left that in the "6 marks" i left.

so most, if not all people attempted the first question in section B.. the part b of that question... what were the 6 marks for?
i wrote "4 conditions" low humidity,high temp,low light, high wind and their effect on stomata correct(stomata close). And an explanation with each.. with temp/humidity/wind i wrote to reduce water loss by transpiration... for low light i wrote to allow no/less CO2 to enter as no light for photosynthesis. Of course all was more explained. Can I expect 6/6?

 

[Metallic9896]

i don't even remember a white blood cell question : p maybe i left that in the "6 marks" i left.

so most, if not all people attempted the first question in section B.. the part b of that question... what were the 6 marks for?
i wrote "4 conditions" low humidity,high temp,low light, high wind and their effect on stomata correct(stomata close). And an explanation with each.. with temp/humidity/wind i wrote to reduce water loss by transpiration... for low light i wrote to allow no/less CO2 to enter as no light for photosynthesis. Of course all was more explained. Can I expect 6/6?

I think so. There was like so much to write my answer was going to be longer than the a) part lol. So yeah I wrote similar to that. Discussed humidity, temperature, light intensity, dryness/wind with their vice versa as well in the explanation and a general comment on why it needs to do this. Some others mentioned that they wrote about ABA and all but I don't think that was necessary since they asked what are the conditions in which opening and closing occurs and explain why it does so, so it wasn't about "how" it does so from what I can tell but you never know about CIE maybe they'll have a huge range of possible points or maybe they have very specific guidelines as to what would score marks.

 

[darks]

I think so. There was like so much to write my answer was going to be longer than the a) part lol. So yeah I wrote similar to that. Discussed humidity, temperature, light intensity, dryness/wind with their vice versa as well in the explanation and a general comment on why it needs to do this. Some others mentioned that they wrote about ABA and all but I don't think that was necessary since they asked what are the conditions in which opening and closing occurs and explain why it does so, so it wasn't about "how" it does so from what I can tell but you never know about CIE maybe they'll have a huge range of possible points or maybe they have very specific guidelines as to what would score marks.

no way do i think that writing about ABA was necessary. It might have one mark where a student links it with severe changes in conditions.

 

[Yo-BKC]

What was the number of base pairs? And for the 1st qs acetate was already combined with CoA = acetyl CoA they asked "P + Acetyl CoA" so obviously its pyruvate and not acetate as acetate is already combind with CoA

And what blood cell do we look at in a sample?

...acetate is made from pyruvate you can't have both of them at the same time

 

[darks]

so i wrote a different answer for the last part of the genetic diagram question... that idk was something like that what does allele A do to give white color?
I linked it to albinism and wrote that it might be coding for a non-competitive inhibitor to an enzyme like tryosinase which leads to no formation of a pigment... and added some more detail....

 

[Metallic9896]

so i wrote a different answer for the last part of the genetic diagram question... that idk was something like that what does allele A do to give white color?
I linked it to albinism and wrote that it might be coding for a non-competitive inhibitor to an enzyme like tryosinase which leads to no formation of a pigment... and added some more detail....

Hahah great minds think alike. Puri duniya ne ya tou repressor protein (linking it to lac operon / transcription factors) wala likha ya koi aur reason. And aik maine aur tumne ye likha hai. I thought I was the only one who linked it to albinism. feels good to know am not alone. I wrote exacty what u did. Like not the non competitive inhibitor precisely just that it doesnt code for an enzyme or produces an inactive enzyme that is essential to the process of pigmentation etc but yes more or less that.

 

[darks]

Hahah great minds think alike. Puri duniya ne ya tou repressor protein (linking it to lac operon / transcription factors) wala likha ya koi aur reason. And aik maine aur tumne ye likha hai. I thought I was the only one who linked it to albinism. feels good to know am not alone. I wrote exacty what u did. Like not the non competitive inhibitor precisely just that it doesnt code for an enzyme or produces an inactive enzyme that is essential to the process of pigmentation etc but yes more or less that.

now we can hope they give us some marks for this. I mean it does make sense