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Biology P22 October 2014

Dharitha_98

Dharitha_98

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Same!
I had to choose between two 4 mark questions in the last 10 minutes, and I successfully ended up writing only a sentence. For one of the 2 questions.

I hope P1 and P3 will be good..
 
Dharitha_98

Dharitha_98

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For the tumour question I wrote about 'abnormal, uncontrolled cell division by mitosos' and about how the plasmid contained genes that affected this mitotic cell division, and how it 'shortens the interphase stage of mitosis'. I think I should also have written about the Tumour suppressor gene and the Proto oncogene, but I didn't. (Because I'm super smart like that. -heavy sarcasm)

For the B cell question, it was the usual "Secondary immune response" answer that was repeatedly asked in many past papers before.
 
B

Bba321

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Y
Dharitha_98 said:
For the tumour question I wrote about 'abnormal, uncontrolled cell division by mitosos' and about how the plasmid contained genes that affected this mitotic cell division, and how it 'shortens the interphase stage of mitosis'. I think I should also have written about the Tumour suppressor gene and the Proto oncogene, but I didn't. (Because I'm super smart like that. -heavy sarcasm)

For the B cell question, it was the usual "Secondary immune response" answer that was repeatedly asked in many past papers before.
Click to expand...
Yay I wrote the same thing :D
what did you write in the role of cell membrane for nitrate ions?
 
Dharitha_98

Dharitha_98

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Oh, for that I wrote that the nitrate ions were small and water soluble, so they couldn't diffuse through the cell surface membrane, because only lipid-soluble substances can pass through it. And I wrote that it diffuses through ion channels by facilitated diffusion.

Although I think it passes through carrier proteins by active transport since...
I'm not sure. What did you write?
 
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Bba321

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Dharitha_98 said:
Oh, for that I wrote that the nitrate ions were small and water soluble, so they couldn't diffuse through the cell surface membrane, because only lipid-soluble substances can pass through it. And I wrote that it diffuses through ion channels by facilitated diffusion.

Although I think it passes through carrier proteins by active transport since...
I'm not sure. What did you write?
Click to expand...
Same but I wrote about both Active transport and facilitated diffusion!
 
forsaken

forsaken

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Dharitha_98 said:
Oh, for that I wrote that the nitrate ions were small and water soluble, so they couldn't diffuse through the cell surface membrane, because only lipid-soluble substances can pass through it. And I wrote that it diffuses through ion channels by facilitated diffusion.

Although I think it passes through carrier proteins by active transport since...
I'm not sure. What did you write?
Click to expand...
you should know that nitrates are polar and large molecules so squeezing through the phospholipid is out of the question.then about trans membrane proteins. carrier protein requires ATP for small molecules or ions large molecules like nitrate will need quite alot of ATP.so your choice is left with co-transporter.correct me if i am wrong
 
Dharitha_98

Dharitha_98

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forsaken said:
you should know that nitrates are polar and large molecules so squeezing through the phospholipid is out of the question.then about trans membrane proteins. carrier protein requires ATP for small molecules or ions large molecules like nitrate will need quite alot of ATP.so your choice is left with co-transporter.correct me if i am wrong
Click to expand...

Haha, now I've absolutely no idea whether I was right or wrong. Wait, the question said 'nitrates ions', right? I don't think they were referring to large molecules or nitrate salts itself.

I was mostly confused about whether they would move in by active transport or diffusion (against or down the concentration grad.) I didn't know whether the concentration of nitrate ions in the roots were more than that in the soil, or vice versa.
 
forsaken

forsaken

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Dharitha_98 said:
Haha, now I've absolutely no idea whether I was right or wrong. Wait, the question said 'nitrates ions', right? I don't think they were referring to large molecules or nitrate salts itself.

I was mostly confused about whether they would move in by active transport or diffusion (against or down the concentration grad.) I didn't know whether the concentration of nitrate ions in the roots were more than that in the soil, or vice versa.
Click to expand...
yes the question was referring to nitrate ions. what i mean by large molecule is they are big compared to O2 and CO2 etc.when a molecule[a] is moving from a high to low conc , nitrates bind to the site of the protein when molecule[a] is moved by it and goes along for the ride.so for nitrates its passive , they dont pay for it
 
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