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OCR 21st Century Science B4 B5 B6 10th June 2016

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Original post by Spectre2000
What about the 2nd six marker? What stages did you guys come up with?


For the multiple schlorosis one i talked about the fatty sheath. I said the damaged one had smaller fatty sheath so it can't insulate as much and also the nerve impulses won't travel as fast. I linked this to the reflex arc and said that their involuntary responses will be quicker (i ordered the thing: effector - sensory neurone - relay nerone - motor neurone - effector) and then i just said for example, they might get burned because their responses were slower. What about you?
Original post by Ella_08
For the multiple schlorosis one i talked about the fatty sheath. I said the damaged one had smaller fatty sheath so it can't insulate as much and also the nerve impulses won't travel as fast. I linked this to the reflex arc and said that their involuntary responses will be quicker (i ordered the thing: effector - sensory neurone - relay nerone - motor neurone - effector) and then i just said for example, they might get burned because their responses were slower. What about you?


I did almost the same response
This paper was decent. I got 1:639 for the ratio and 0.09% for the other one. I though it was staged A and C, as at B there wasn't actually any mitosis however at C (from tadpole to adult frog) there was as obviously there has to be cell division in order for the animal to grow. I put Amy for the dropping food and the grasp reflex for the last one. I got a curve of best fit and 42 for the one about carbon dioxide.

What did you guys put for the one about the enzyme, methanol and ethanol? Completely threw me as I've always thought that an active site can only fit one substrate only?
Original post by NiamhM1801
This paper was decent. I got 1:639 for the ratio and 0.09% for the other one. I though it was staged A and C, as at B there wasn't actually any mitosis however at C (from tadpole to adult frog) there was as obviously there has to be cell division in order for the animal to grow. I put Amy for the dropping food and the grasp reflex for the last one. I got a curve of best fit and 42 for the one about carbon dioxide.

What did you guys put for the one about the enzyme, methanol and ethanol? Completely threw me as I've always thought that an active site can only fit one substrate only?


Seems like we got similar answers, except for the percentage one. I think I got your answer in my working so i might get 1/2 marks. I got Amy too and the curve of best fit.

For that one i had no idea because I thought it was more a B2 question. Anyway I just said that they are complementary and the methanol/ethanol are similar shapes so if more of the methanol is produced it can inhibit the growth of the ethanol. A complete guess
Reply 64
Original post by NiamhM1801
This paper was decent. I got 1:639 for the ratio and 0.09% for the other one. I though it was staged A and C, as at B there wasn't actually any mitosis however at C (from tadpole to adult frog) there was as obviously there has to be cell division in order for the animal to grow. I put Amy for the dropping food and the grasp reflex for the last one. I got a curve of best fit and 42 for the one about carbon dioxide.

What did you guys put for the one about the enzyme, methanol and ethanol? Completely threw me as I've always thought that an active site can only fit one substrate only?


I got the exact same answers as you and I talked about how they would both fit the active site but different products would be made as the top of the molecule is shaped differently. I also said they would have to use that substrate as the enzyme is specific to very substrate shapes and both would fit the active site.
Original post by Ella_08
For the multiple schlorosis one i talked about the fatty sheath. I said the damaged one had smaller fatty sheath so it can't insulate as much and also the nerve impulses won't travel as fast. I linked this to the reflex arc and said that their involuntary responses will be quicker (i ordered the thing: effector - sensory neurone - relay nerone - motor neurone - effector) and then i just said for example, they might get burned because their responses were slower. What about you?


I practically said the same thing. I did waffle a bit in the end though saying something about uncoordinated movement due to the slowness of the impulses.
Original post by Spectre2000
I practically said the same thing. I did waffle a bit in the end though saying something about uncoordinated movement due to the slowness of the impulses.


Good :smile: that doesn't seem like waffling, it seems pretty sensible.

And I found this https://www.mssociety.org.uk/what-is-ms/information-about-ms/about-ms and we got similar stuff
Original post by Ella_08
Good :smile: that doesn't seem like waffling, it seems pretty sensible.

And I found this https://www.mssociety.org.uk/what-is-ms/information-about-ms/about-ms and we got similar stuff


Thanks I guess and yeah that sounds about right; at least I've gotten something right for sure. Think I screwed up the other 6 marker about mitosis and meiosis though-got the wrong stages by the sounds of it.
Reply 68
Original post by NiamhM1801
This paper was decent. I got 1:639 for the ratio and 0.09% for the other one. I though it was staged A and C, as at B there wasn't actually any mitosis however at C (from tadpole to adult frog) there was as obviously there has to be cell division in order for the animal to grow. I put Amy for the dropping food and the grasp reflex for the last one. I got a curve of best fit and 42 for the one about carbon dioxide.

What did you guys put for the one about the enzyme, methanol and ethanol? Completely threw me as I've always thought that an active site can only fit one substrate only?


I got similar answers, I thought it was a much better paper the B1, B2, B3.

I put that if both substrates fit the active site of the enzyme then if the ethanol was broken down, it could prevent the methanol from being broken down, therefore preventing toxic products from being released.
Reply 69
Original post by Spectre2000
Thanks I guess and yeah that sounds about right; at least I've gotten something right for sure. Think I screwed up the other 6 marker about mitosis and meiosis though-got the wrong stages by the sounds of it.


Yeah but you'll probs get 3-4 marks for knowing 1 of the stages and describing similarities and differences, so don't worry!
Original post by Lsford
Yeah but you'll probs get 3-4 marks for knowing 1 of the stages and describing similarities and differences, so don't worry!


Fingers crossed! :biggrin: I'll be fine with 3 marks on that-not like you need 6 on every long answer for an A right?
Accidentally picked A and B for the mitosis/meiosis 6 mark and forgot to take healthy people away from population :facepalm:

Apart from that I think it was fine. For the enzyme one, it was because they were the same shape @Ella08, although I couldn't think of much more to say past that.
Original post by babbajung
Was stage A or stage B mitosis?


I got stage B as mitosis


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What did you guys get for the first 6 Marker


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Reply 74
Original post by Spectre2000
Fingers crossed! :biggrin: I'll be fine with 3 marks on that-not like you need 6 on every long answer for an A right?


Yeah, you need like 3-4 as long as you've done ok on the rest of the paper, i know someone who got 2 on every long marker and still came out with an A so I think you'll be ok!
Original post by Spectre2000
Thanks I guess and yeah that sounds about right; at least I've gotten something right for sure. Think I screwed up the other 6 marker about mitosis and meiosis though-got the wrong stages by the sounds of it.


I reckon they'll only give out 2 marks for identifying the stages. As long as you talked about mitosis and meiosis then don't worry too much
Reply 76
Original post by Ella_08
I reckon they'll only give out 2 marks for identifying the stages. As long as you talked about mitosis and meiosis then don't worry too much


Yeah, I agree. I think that the similarities and differences part of the question is gonna be the most heavily marked. But that's just my opinion so
Original post by emmald583
Accidentally picked A and B for the mitosis/meiosis 6 mark and forgot to take healthy people away from population :facepalm:

Apart from that I think it was fine. For the enzyme one, it was because they were the same shape @Ella08, although I couldn't think of much more to say past that.


I'm glad someone also said they were the same shape :wink: I probably got 2/3 for that question which is alright. I didn't like that thing about the egg cell and nucleus, messed up some answers there definitely. I did ok on the 6 markers just not some 2 and 3 markers
Original post by Ben.M
I got similar answers, I thought it was a much better paper the B1, B2, B3.

I put that if both substrates fit the active site of the enzyme then if the ethanol was broken down, it could prevent the methanol from being broken down, therefore preventing toxic products from being released.


My friend put something along those lines. I'm pretty sure I misinterpreted the question - I thought it meant AFTER the methanol had already been broken down so I had no idea how ethanol would cure that. I might have got 2 marks for writing that they both have similar shapes (1) so they both fit into the active site (1). Might be being a bit ambitious there though haha
Reply 79
You know the question on the baby having DNA of 3 people or whatever, and that some people object to that, what did you guys say?

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