AQA BIOL5 ~ 17th June 2013 ~ A2 Biology Watch
I know this was a while ago, but does this mean that more transcription factors mean, like, the gene is expressed more times? I thought it was either expressed or not.. but with more transcription factors the code is copied by mRNA..blah blah.. more often, so more chloroplasts would be produced?
Secondly, in vitro requires PCR. In PCR have we isolated the gene using restriction endonuclease or reverse transcriptase...or have we just taken the DNA and copied it?
What are the advantages and disadvantages of both these gene cloning techniques.
Notes on these will be greatly appreciated...thanks so much guys
Seeing as though there are like 3 exam papers and one specimen paper, how are you guys developing exam technique for this paper? Would it be good to do exam pro, because im worried it will have the current spec paper questions
Transcriptional factors bind to the DNA and begin the process of transcription. Transcriptional factor's binding site can be blocked by inhibitors which is when a gene is not expressed. So a cell with more uninhibited transcriptional factors would lead to more of that certain protein being produced. I don't think it's an expressed or not situation as the needs of the cell will vary. Which is why there are hormones like oestrogen that go into cells and bind to receptors on transcriptional factors causing the inhibitor to be released and so can bind to DNA. I welcome correction but I think this is right, hope it helps
I'm going to start looking through New Scientist and just general bits and bobs around the internet to get a few points down that we can share for off spec stuff.... unless theres already a document floating around that people can link me to?
Gel electrophoresis with my DNA!
Hi, I have a few questions about DNA fingerprinting: why do we have to transfer the fragments onto a nylon membrane to analyse them, why can't they just be left in the gel? Also, in the book it says that the gel is submerged in an alkali to separate the double strands into single strands- so what happens to the other strand that isn't being analysed ( the other half of the double strand)