A2 Biology OCR June 2015 Revision Thread

I'm only half way through the stuff and I'm hating my life. Getting to sliding filament and man don't care no more. Man doesn't even wanna go to first choice uni.

Reply 4161

amorrison

11

Original post by Nadwuar

And the mark scheme answer to dat famalam?

That would be the following
1) Prior to autumn(when leaves fall) high concentration of auxin and cytokinins prevent leaf senescence(ageing)- these are agonist in that they work together
2) Auxin and Cytokinins ensure that the leaves have a sink for phloem transport of sugars
3)As autumn arrives, levels of cytokinins drop, and hence triggering leaf senescence
4)Leaf senescence causes a drop in auxin levels which makes the cells in the abscission layer more sensitive to ethene
5)Ethene is antagonist to cytokinins and auxin. Ethene promotes leaf fall
6) Ethene increases cellulaze production and this enzyme separate the petiole from the stem.
7) A protective layer is formed in the abscission zone to prevent microbes from entering the plant.

That's the process and should score more than full marks!!

Reply 4162

amorrison

11

Original post by Nadwuar

Difference between reproductive and non reproductive cloning? A mark scheme answer would be preferable

Reproductive cloning: Whole new individual is made e.g. Dolly the sheep
Non-reproductive cloning: Cells, tissues or organs are all produced and place into the individual.

Reply 4163

CallMeJay

12

Original post by blacklotus1

I'm only half way through the stuff and I'm hating my life. Getting to sliding filament and man don't care no more. Man doesn't even wanna go to first choice uni.

LOOOOOOOOOOOOOOOOOL

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Reply 4164

Jae578

2

Anyone else think module 4 and 2 are ****boys?

Reply 4165

blacklotus1

1

I'm fully giving up tbh, I did okay in F214 but F215 is peak

Reply 4166

Nadwuar

2

Original post by blacklotus1

I'm fully giving up tbh, I did okay in F214 but F215 is peak

Man said F215 is peak, dats an understatement cuhh

Reply 4167

TruMuslima

2

Yup. I'm planning on retaking both next yr already. Goodbye to gap yr :frown:

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Reply 4168

blacklotus1

1

Original post by TruMuslima

Yup. I'm planning on retaking both next yr already. Goodbye to gap yr :frown:

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Yeah I wish I had the luxury of a gap year option fam

Reply 4169

CallMeJay

12

Original post by blacklotus1

I'm fully giving up tbh, I did okay in F214 but F215 is peak

1 final push, bruh. Then we can finally dash away this bullocks

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Reply 4170

Nadwuar

2

Guy's someone please explain to me how you would answer a question similar to the rennin protein one but about Golden Rice?

Reply 4171

blacklotus1

1

Original post by CallMeJay

1 final push, bruh. Then we can finally dash away this bullocks

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Fam this actually inspired me. I'm still gonna do **** but it's nice that people support you you get me

Predictions anyone?

Okay fellow fail-ees it is with great curiosity that I ask you what the **** you call a bunch of undifferentiated plant cells (I've forgot the damn name)... In tissue culture, where you get the meristems then grow them in-vitro, what the **** is that blob of cells called??

EDIT: Okay, it is a Callus, which I originally thought but then googled it and lots of images of people with hard skin on their feet came up... oh well.

(edited 8 years ago)

Reply 4174

Dark Elixir

11

Original post by ezradennis

Predictions anyone?

Failure

Reply 4175

Shostakovish

12

So, I planned to an 'all-nighter! LOL!', but I actually collasped by 11:20 and woke up now...yay

Reply 4176

Shostakovish

12

Original post by Dark Elixir

Okay fellow fail-ees it is with great curiosity that I ask you what the **** you call a bunch of undifferentiated plant cells (I've forgot the damn name)... In tissue culture, where you get the meristems then grow them in-vitro, what the **** is that blob of cells called??

EDIT: Okay, it is a Callus, which I originally thought but then googled it and lots of images of people with hard skin on their feet came up... oh well.