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AQA BIOL5 ~ 17th June 2013 ~ A2 Biology

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Original post by samfreak
i got 84 in bio4, could i still be abl to fet an a star overall? do i hav to get atleast 90% in BOTH bio 4+5 for me to get an a star?

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You need 186 from both unit 5 and unit 6 to get an A* (270 in your A2 units, plus at least 480 UMS overall for units 1-6). So it's possible, but you'll need to get quite high UMS.
Reply 1921
Avatar for ahmmm
ahmmm
8
anybody got any good sites with model essays or good videos that explain stupid things like gene tech??
Reply 1922
Avatar for peebs123
peebs123
For the essay... Does anyone have any examples of wider reading that can be used, like from the New Scientist magazine?
Try mcgraw hill, click site map and it has all the topics; really good for animations.
Can someone please post the link for the website for further reading for the essay. Someone post it before but I can't seem to find it.

Thanks :smile:
Reply 1925
Avatar for charch95
charch95
Original post by loveheartsandall
Hi all,

On page 241 of the AQA biology text books, it talks about how siRNA is derived from DOUBLE STRANDED RNA. My question is since when were RNA double stranded? I thought both mRNA and tRNA were single-stranded polynucleotide chains?


In my notes that my teacher gave me, it says that RNA-dependent RNA polymerase (RDR) which was discovered in 2004 makes double stranded RNA. The RDR uses mRNA to make double-stranded RNA so the protein complex specifically breaks down mRNA from with the siRNA is made- this is an example of negative feedback.
(edited 10 years ago)
Reply 1926
Avatar for ahmmm
ahmmm
8
anybody got any model essaysssss ?? :confused:
Original post by neelam123h
Can someone please post the link for the website for further reading for the essay. Someone post it before but I can't seem to find it.

Thanks :smile:


oh please quote me if you find the link :smile:
Reply 1928
Avatar for ahmmm
ahmmm
8
http://filestore.aqa.org.uk/subjects/AQA-2410-W-TRB-GOA-SEQ.PDF

anybody know if this is relevent to next mondays exam as well?
Thought i'd repost this, from a few pages back - I didn't make it but it is really useful :smile:

http://quizlet.com/11320494/learn/
Can someone please outline fluorescent markers - page 253 in the textbook! I don't really understand it!


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with regards to DNA sequencing and gel electrophoresis on page 268 it says "In this way the whole sequence of bases on the terminator nucleotides was found to be AGCTTGAC and this is the sequence on one of the strands of the newly formed DNA." i thought that it was the sequence of the DNA we we originally had that we were trying to find though and not the sequence of the terminator nucleotides. Therefore the sequence we would be trying to find would be the opposite bases to the terminator nucleotide sequence?
Reply 1932
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rommy123
does anyone have any good notes on gene technology??
Reply 1933
Avatar for peebs123
peebs123
Does anyone know what the grade boundaries were for the unit 5 specimen paper on the AQA website? :smile:
Anyone else find that paper really hard?
(edited 10 years ago)
Original post by peebs123
Does anyone know what the grade boundaries were for the unit 5 specimen paper on the AQA website? :smile:
Anyone else find that paper really hard?


Im not sure what the grade boundaries are for the spec, but i went with the june 2010 grade boundaries. You are not the only one, i found this paper stupidly hard also.
Original post by hollywils
Can someone please outline fluorescent markers - page 253 in the textbook! I don't really understand it!


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Hello! The plasmid that the DNA fragment is going to be inserted into has a gene for fluorescence in it, so that plasmid will fluoresce. However, the DNA fragment that you want to insert will be inserted into this gene, like when you use antibiotic resistance as gene markers. Thus, the plasmids that have taken up the gene won't fluoresce because the DNA has been inserted in the middle of the DNA that would usually code for fluorescence, so the bacteria won't fluoresce that have taken up these plasmids.

This means that when the scientist looks under a microscope, the scientist can identify the bacteria colonies that don't fluoresce, and then retain those, as they will be the ones the cultures that have been transformed.

Hope this makes sense! Fluoresce now doesn't seem like a word.
Original post by peebs123
Does anyone know what the grade boundaries were for the unit 5 specimen paper on the AQA website? :smile:
Anyone else find that paper really hard?


There aren't any grade boundaries for the specimen paper because nobody has sat it, as it was released before this paper was ever done, to give teacher & students an idea of what the new paper would be like :smile:
Reply 1937
Avatar for ahmmm
ahmmm
8
model essays anyone?
What outside reading are you putting into your essays?
Original post by JenLivYoung
Hello! The plasmid that the DNA fragment is going to be inserted into has a gene for fluorescence in it, so that plasmid will fluoresce. However, the DNA fragment that you want to insert will be inserted into this gene, like when you use antibiotic resistance as gene markers. Thus, the plasmids that have taken up the gene won't fluoresce because the DNA has been inserted in the middle of the DNA that would usually code for fluorescence, so the bacteria won't fluoresce that have taken up these plasmids.

This means that when the scientist looks under a microscope, the scientist can identify the bacteria colonies that don't fluoresce, and then retain those, as they will be the ones the cultures that have been transformed.

Hope this makes sense! Fluoresce now doesn't seem like a word.


Thanks :smile:


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