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A level Biology: Post your doubts here!

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how the proportional increase in cell no. is calculated
and what is meaning of 4th bullet point.i cant understand it
 

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Can i have some notes or wesite or tips or what specific area should i study for the biology practicals, paper 3 ??
 
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Can i have some notes or wesite or tips or what specific area should i study for the biology practicals, paper 3 ??

for paper 3 you should learn magnification calculations , micrometry, plan , annotated and label diagrams and food tests ... u ought to attend practical classes for that.. cuz practice makes one perfect
 
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PHOTOSYNTHESIS essay type question.. help...
1) Describe the structure of photosystems and explain how a photosystem functions in cyclic photophosphorylation.
2)Explain briefly how reduce NADP is formed in the light dependent stage of photosynthesis and is used in the light independent stage.
3)Describe the transfer of light energy to chemical energy in ATP during photosynthesis.
4) Outline the light dependent stage of photosynthesis.
 
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I need help with a question paper. It is M/J/2011 version 12 paper 1 question 10. Why is the answer peptide bond only? Can't disulphide bonds form between two cysteine molecules too? Please explain why the other options can be eliminated except for D.
 

Nibz

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Because when two amino acids combine, they are joined by peptide bonds only.
 
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What is meant by t-test, degrees of freedom, null hypothesis etc.?
also does anyone have ay goos notes for paper 5?
 
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Outline the principles of electrophoresis as used in sequencing this DNA?
ms does not anywhere mentions sequencing of DNA......WHATS THIS HYPOCRISY,,,,,is it bcos dna sequencing is not in syllabus learning outcmes?
1 cut DNA (into fragments) ;
2 by, restriction enzymes / named enzyme ;
3 place on (agarose) gel ;
4 apply, current / p.d. / electricity ;
5 fragments travel towards anode ;
6 short fragments travel, further / faster, than long ones ; A mass of fragments
7 visualise DNA with UV light / other means of visualisation ;
8 AVP ; e.g. Southern blotting / described
 

Nibz

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what does standard error tells us about?......
"For a normally distributed population, the standard error provides an estimate of the degree of variation of the means of a number of equal-sized samples taken from the population."
 

omg

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please can i getttt the markscheme ov nov 2011 paper 4!!! its urgenttttttttttttttttttttttt
 
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