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Edexcel 6BIO2 ~ 3rd June 2013 ~ AS Biology

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Reply 1800

Rickrossmmg

A model mark scheme anyone?

Reply 1801

billyfisher100

Original post by 344302

Expected the can do tasks as predicted by most of tsr.

Did not expect taxonomies and I just waffled my way through there.

Dumb mistake on suggesting cell cycle stage. What's wrong with me I will never know!

Didn't really have much to say for the acrosome reaction when the egg hardens because I didn't know about it in enough detail.

Can someone for gods sake tell me if for the last question they wrote selection pressure , rate of reproduction and size of gene pool!! Is that not what determines being able to survive!!!

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On that awful last question, I wrote competition in the same niche, leading to predation, the affect of human activity (less than 1% of grassland is unaffected) and the use of pesticides limiting their food source. For the cell cycle thing, I said cytoplasmic division, because, as it's a plant cell, there is evidence of cell plate development. And I thought taxonomy (kingdom phylum class order family genus species) was off the spec??! All of this hopefully means that grade boundaries will hopefully be in the mid to high fifties.

Reply 1802

344302

Original post by billyfisher100

I reckon at the most 58-60 for an A. Some hard questions though for HSW. That question about the black-footed stoat reintroduction threw me a bit. But those lovely questions on cells, mitosis and zoos may push the boundaries up a little. Also, did anyone find it difficult to get 4 marks for that cortical response question with mammalian fertilisation?

Yup all I could think about was the zona pellucida hardening and then the sperm nucleus only entering ..

And then I threw in that they fuse and make a zygote in hope of desperate marks,

What did u put for reintroduction into the wild?

And also, the Zoo question was specifically asking about genetic diversity wasn't it? .. Oh ****

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Reply 1803

1192162

Original post by Meehar17

For the cellulose microfibrils section on the cellulose q , did you tick or cross the 1-4 glycosidic bond and what did you do for the 1-6 one also?

For cellulose I said it has only 1,4 glycosidic bonds and the cellulose microfibrils has 1,4 and 1,6 glycosidic bonds. BUT I'VE BEEN TOLD THAT'S WRONG :'(

Reply 1804

JaayBiology

For once EDEXCEL gave a nice exam :P

Reply 1805

billyfisher100

Original post by Meehar17

For the cellulose microfibrils section on the cellulose q , did you tick or cross the 1-4 glycosidic bond and what did you do for the 1-6 one also?

Ok, I put for cellulose crosses in the 1,6 and ticks in both the 1,4 ones.

Reply 1806

Meehar17

Original post by carinaly

For cellulose I said it has only 1,4 glycosidic bonds and the cellulose microfibrils has 1,4 and 1,6 glycosidic bonds. BUT I'VE BEEN TOLD THAT'S WRONG :'(

The cellulose molecule does only have 1-4 bonds but I'm unsure about the cellulose microfibrils

Reply 1807

username893771

Original post by 344302

Tick
Cross
Cross

Oh and that cellulose molecule vs microfibril caused a Lot of confusion at my school. I think I got 2/4 on that.

Overall, okay paper, I can see the grade boundaries being slightly lower because of the new questions that haven't come up before.

Screwed it up big time. Hopefully scraped an A. Maybe coursework and my 113 ums in unit 1 will get me an overall A. Sigh. I was really looking forward to that A* prediction. Guess not!

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AFAIK for an A* you need 480/600 UMS with 270 UMS coming from your A2 exams, so at the moment you're on track don't worry :smile:

Reply 1808

344302

Original post by Meehar17

The cellulose molecule does only have 1-4 bonds but I'm unsure about the cellulose microfibrils

I put tick for molecule cross for microfibril.

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Reply 1809

billyfisher100

Original post by Meehar17

The cellulose molecule does only have 1-4 bonds but I'm unsure about the cellulose microfibrils

I'm pretty sure two crosses for 1,6 and two ticks for 1,4 as a microfibril is still made of cellulose, so it will have 1,4 bonds. None of them have 1,6 bonds. What were the other boxes?

Reply 1810

AbiHem

What stage was the cell cycle at???

Reply 1811

billyfisher100

On balance, for me, I think it went quite well, apart from that sodding last question...

Reply 1812

billyfisher100

Original post by AbiHem

What stage was the cell cycle at???

Cytokinesis/cytoplasmic division, as there was a cell plate forming.

Reply 1813

Meehar17

What did you guys put for the question about how they are classified into their domains? And also the question about why that persons theory wasn't accepted (can't remember his name)

Reply 1814

344302

Original post by AbiHem

What stage was the cell cycle at???

Interphase.

Clever me decided to put S?? What was going through my mind

I was even disputing changing it to g1 or g2 but I knew it was interphase but I don't know what threw me

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Reply 1815

Rubyturner94

Original post by billyfisher100

Cytokinesis/cytoplasmic division, as there was a cell plate forming.

i put interphase :frown:

,

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Reply 1816

billyfisher100

Original post by Meehar17

What did you guys put for the question about how they are classified into their domains? And also the question about why that persons theory wasn't accepted (can't remember his name)

All I can remember is peer review for Woese... :redface:

I hope I didn't miss out a question or something DO you mean the one about taxonomy?

Reply 1817

viyas07

this was actually an easy paper with the exception of the first page which required detailed knowledge and taxonomic grouping, and then the only other questions that people would have made mistakes on would be the tick box questions on cellulose and cellulose microfibrils n then the one on digitalis and withering...but otherwise, everything else was straight from previous papers

and asking a 3/4 mark question on prophase is a bit harsh..:/ and so was the 3-4 marker on captive breeding- hopefully they dont couple certain points together like inbreeding depression being prevented by studbooks etc

and the diagrams were sooo bad!!