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A level Biology: Post your doubts here!

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u shud say crossing over in prophase 1 because most ov markschemes say prophase 1 apart from one duffer examiner who said metaphase 1
 
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well....pleaseeee some on emake a thread for A2 BIOOO..........PLEASEEEEE.....I MEAN A STICKY THREAD....ITS A REAL MESS HERE.......
 

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pls pls pls can i get a note on the hazards and benfits of gene technology with specific examples??????????
 
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What is the difference between qualitative, quantitative, semi-qualitative, and semi-quantitative analysis? :confused: or what are the separately? their definitions?
Think about food tests etc. You can test whether each solution has sugars, fats etc, but sometimes you can't measure the amount of fat/sugar in the solution, or sometimes you can just measure whether 1 solution has more or less than another, etc.

Qualitative is when you can just say 'X' has fat in it and 'Y' has fat in it. You can't say whether X or Y has more fat.
Semi-qualitative i.e. Benedicts, when you either measure the time taken to reach a particular colour i.e. red, or the mass of the precipitate/intensity of the colour, is when you can say 'X has glucose, and Y has glucose, but X has more glucose than Y'
Quantitative is when you can say 'X' has 3.04 grams of sugar, y has 1.84 grams of sugar.

Semi-quantitative is harder to define, i think its when you get an approximate value.

Hope you learnt something.
 
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Hey people, I got sum thing from ms that sounds contradicting to me.....

스크린샷 2012-04-26 오후 12.37.30.png point 8 where it says speed increased by 50 times / 0.5 to 100... and why is that 50 times?
 
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hi all, please tell me that what happens to a chromosome between the end of anaphase and the start of the next mitosis.
 
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hi, im an AS student..im having problem to do p3 paper for bio...could you help me to inform prospective topic which will be tested in the coming examination..pls..i really need help..pls..
 
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Explain, using named examples, how mutation can affect phenotype. [7].this is from June 2006. can some one please give me a note on down's syndrome as it is required for this answer as stated in marking scheme...
 
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