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Edexcel IAL Biology Unit 5 (WBI05) Scientific Article Discussion - June 2016

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If temperature is greater tensile strength would be smaller. It would be easier to break/tear the fibre at higher temperature..reason is not known but could u think of one? I guess bonds holding the cells together become weaker at high temperatures

Yeah I guess that would be the reason since the plant fibre is made of fibres that are connected by bonds so higher temperatures will cause them breaking and therefore low tensile strength

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(edited 7 years ago)

Reply 261

Aimen.

Original post by user179

Hey

I think you first have to mix your DNA sample with restriction enzyme so the DNA sample is cut into fragments. I think you add the DNA fragments to the wells, not whole DNA samples. Makes sense?

Oh yea I totally forgot that imp. most step in here..
Thanks for adding in! X

Reply 262

Chinu_Cheeku97

Hii! I have the philip alan student unit guide for bio 3/6 in pdf. If you want it. Pm your email to me :smile:

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Reply 263

Polpi

Original post by PlayerBB

I guess if they would gives us gel electrophoresis, they won't include CF, they will more ask us that two people were suspects in a crime, their DNA was amplified by PCR, how will GE will show us which one of the two suspects is more likely to be the criminal, plan an investigation.......

The dependent variable would be the size of DNA bands
The independent variable would be DNA sample from suspect used

But I am just guessing

Spoiler

hahahahha don't worry i have better things to do in the future than ruin potential careers with meaningless mark schemes :P

Reply 264

Sandy_Vega30

Original post by Chinu_Cheeku97

Hii! I have the philip alan student unit guide for bio 3/6 in pdf. If you want it. Pm your email to me :smile:

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You already know mine! Please send me! :smile:

Reply 265

Sandy_Vega30

Guys! What are the questions that have chi squared test and mann whitney tests? I cant find any from edexcel apart from t-test and Spearman's Rank. Help please?

Reply 266

TheMadHatteress

Has anyone sopved Jan 2016? It's like the hardest paper EVER. God I feel so demotivated now. :frown:

Reply 267

PlayerBB

Original post by TheMadHatteress

Has anyone sopved Jan 2016? It's like the hardest paper EVER. God I feel so demotivated now. :frown:

Yeah!!!!!! It's SO FREAKING hard like the 3rd and the 2nd questions ate normal but the first was so hard
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Reply 268

TheMadHatteress

Original post by PlayerBB

Yeah!!!!!! It's SO FREAKING hard like the 3rd and the 2nd questions ate normal but the first was so hard
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I know right! And now i feel so demotivated :frown:

after all that practicr with all those other past papers, I can't believe this :frown:

Reply 269

~xSarahx~

Does anyone know any good websites where I can go over all the statistical tests? (T-test, Chi-square)

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Reply 270

PlayerBB

Original post by Polpi

hahahahha don't worry i have better things to do in the future than ruin potential careers with meaningless mark schemes :P

Hahahaha well that's good, best of luck :yy:

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Reply 271

Polpi

Original post by PlayerBB

Hahahaha well that's good, best of luck :yy:

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Btw do you know what they mean by continuous prose ? Like wrote in paragraphs and organise everything step by step ?

Reply 272

Sandy_Vega30

Hey! Could someone explain to me when to use Systematic sampling and when to use random sampling? And what's the difference between the two?

Reply 273

Quirky01

Original post by Sandy_Vega30

Hey! Could someone explain to me when to use Systematic sampling and when to use random sampling? And what's the difference between the two?

Systematic- to measure distribution /pattern
Random-to measure abundance

Reply 274

Quirky01

What should be limitations for gel electrophoresis and tensile strength?
Asking u guys particularly!😊😊😊

Reply 275

mystreet091234

How to keep oxygen concentration constant inside a respirometer?

Reply 276

Polpi

Original post by Quirky01

What should be limitations for gel electrophoresis and tensile strength?
Asking u guys particularly!😊😊😊

Gel electrophoresis- gel denatured,pH changes due to contamination
Temperature fluctuating
Tensile strength-microbial action this weakening the tensile strength.
You know when you add use the same fibre when adding the heavier weights this reduces the elasticity of the fibre throughout the experiment. Watch the video on it through the link the guy talks about the limitations.

Reply 277

Polpi

Original post by mystreet091234

How to keep oxygen concentration constant inside a respirometer?

Oxygen sensing probes ? No that would just be to measure it idk how to control it

Reply 278

Quirky01

Original post by mystreet091234

How to keep oxygen concentration constant inside a respirometer?

Why would u keep oxygen concentration constant? If u look at a spirometer trace u will see that the trace slopes downwards showing volume of oxygen decreases..we do not keep volume of oxygen constant in spirometer..we only absorb any CO2 produced 😊