ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Biology => Topic started by: bar0029 on October 28, 2010, 10:40:09 am
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1. cladograms, whats the best method to draw them
2. how to come up with selection pressures?
3. what should i do during the day? what foods should i eat? should i study? etc.
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1. cladograms, whats the best method to draw them
Usually a good way to draw it is to draw a diagonal line with diagonal lines coming out of it, in different directions like:
http://www.google.com.au/imgres?imgurl=http://www.accessexcellence.org/AE/AEPC/WWC/1995/clado-cladogram.gif&imgrefurl=http://www.accessexcellence.org/AE/AEPC/WWC/1995/simulation_restriction.php&usg=__qBwoKsM-62SHxGokO8_mQVOEPBg=&h=264&w=420&sz=6&hl=en&start=0&zoom=1&tbnid=xYohFt2H3wPnGM:&tbnh=105&tbnw=167&prev=/images%3Fq%3DCladogram%26um%3D1%26hl%3Den%26sa%3DN%26biw%3D1600%26bih%3D682%26tbs%3Disch:1&um=1&itbs=1&iact=hc&vpx=802&vpy=80&dur=759&hovh=178&hovw=283&tx=169&ty=118&ei=97nITPDkJ83ccJP84O8K&oei=97nITPDkJ83ccJP84O8K&esq=1&page=1&ndsp=33&ved=1t:429,r:4,s:0
2. how to come up with selection pressures?
Look for what is causing one prevailing trait over another. For example if there is an antibiotic introduced to some bacteria, where there are some that survive and undergo binary fission (etc.) while there are others that die, then the selection pressure which is causing this change is the antibiotic being exposed to the bacteria.
3. what should i do during the day? what foods should i eat? should i study? etc.
Intense study should have been done yesterday and possibly today.
Do not eat too many fatty nor sugary foods especially on the exam day, you do not want to have to go to the toilet during the exam. Fatty foods can slow brain activity in large amounts.
You also do not want to eat too much food in general. Digestion causes increased bodily resources to digestion itself etc. (possibly) causing you to be more tired.
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Any other tips for to do's tomorrow???
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Don't do too much tomorrow. Get all the final 'to dos' done today. It is those final 'to dos' that tend to take a long time and stress you out.
I recommend going to the toilet before the exam, so go early to school.
Before the exam, don't look at people too much. Many will be stressed so if you do that can bring stress and anxiety to you.
It might sound strange but it may work for you.
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Don't do too much tomorrow. Get all the final 'to dos' done today. It is those final 'to dos' that tend to take a long time and stress you out.
I recommend going to the toilet before the exam, so go early to school.
Before the exam, don't look at people too much. Many will be stressed so if you do that can bring stress and anxiety to you.
It might sound strange but it may work for you.
yeah, definitely avoid the stressed lunatics!
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+1 to you!
by the way, what is the scratch technique?
also DNA recombination do i need to practice the method? or just basically need to know that the transgene is inserted into the plasmid which have both been cut by the restriction enzyme, and then joined by ligase; incorporated into the genome of the bacteria (or rather) which will produce the desired product. e.g., human insulin?
btw does anyone undertsnad how to do Q3 multiple choice of 2006 vcaa paper?
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Three different alleles, arranged in sets of 2: AA, AB, AC, BB, BC, CC
Scratch technique is using your fingernail to mark answers during reading time
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+1 to you!
by the way, what is the scratch technique?
also DNA recombination do i need to practice the method? or just basically need to know that the transgene is inserted into the plasmid which have both been cut by the restriction enzyme, and then joined by ligase; incorporated into the genome of the bacteria (or rather) which will produce the desired product. e.g., human insulin?
btw does anyone undertsnad how to do Q3 multiple choice of 2006 vcaa paper?
Scratch technique:
Where you make a mark using your fingernails on the exam (scratching on the multiple choice) during the reading time so that when the writing time starts you can quickly locate the scratches and choose the answer.
Once again I do not recommend this.
I have a question:
Does RNA polymerase bind to the promoter in transcription? Do we need to know this? Or are we free to say 'RNA polymerase binds to the template strand'.
Would you say it binds to the promoter or the promoter region?
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+1 to you!
by the way, what is the scratch technique?
also DNA recombination do i need to practice the method? or just basically need to know that the transgene is inserted into the plasmid which have both been cut by the restriction enzyme, and then joined by ligase; incorporated into the genome of the bacteria (or rather) which will produce the desired product. e.g., human insulin?
btw does anyone undertsnad how to do Q3 multiple choice of 2006 vcaa paper?
Scratch technique:
Where you make a mark using your fingernails on the exam (scratching on the multiple choice) during the reading time so that when the writing time starts you can quickly locate the scratches and choose the answer.
Once again I do not recommend this.
I have a question:
Does RNA polymerase bind to the promoter in transcription? Do we need to know this? Or are we free to say 'RNA polymerase binds to the template strand'.
Would you say it binds to the promoter or the promoter region?
I think either is fine...
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I have no idea whether you need to know it or not, but yeah there's a promoter region that regulates transcription
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i say:
RNA polymerase binds to the promotor region of the DNA template strand causing the DNA double helix to unwind resulting in exposed DNA nucleotides.
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i say:
RNA polymerase binds to the promotor region of the DNA template strand causing the DNA double helix to unwind resulting in exposed DNA nucleotides.
Wait, does the binding to the promoter region induce the DNA to unwind? I thought it was so the synthesis of mRNA could begin.
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for mRNA to be produced you need ssDNA to build off
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this is what happens:
1. RNA polym. binds to the promotor region of the DNA causing it to unwind exposing nucleotides on the template strand.
2. RNA polym. add free RNA nucleotides to the exposed nucleotides on the template strand according to the base pairing rule.
3. When the terminator region is reached, the process of transcription stops and the final product is mRNA in prokaryotes and pre-mRNA in eukaryotes.
does anyone know how to do Q10 of MC from biol exam 2005.
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It's more precise to say:
"RNA polymerase binds to the promoter region and moves along the gene; the free RNA nucleotides are added to the growing pre-mRNA strand whilst the DNA is unwound and DNA bases exposed."
http://www.youtube.com/watch?v=WsofH466lqk
Watch this, it's good for transcription.
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In order for the transcription to take place, the enzyme that synthesizes RNA, known as RNA polymerase, must attach to the DNA near a gene. Promoters contain specific DNA sequences and response elements which provide a secure initial binding site for RNA polymerase and for proteins called transcription factors that recruit RNA polymerase. These transcription factors have specific activator or repressor sequences of corresponding nucleotides that attach to specific promoters and regulate gene expressions. - Wikipedia (Promoter (biology)).
How can promoters (the actual promoter itself) regulate gene expression?
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promotors don't themselves regulate gene expression
instead: it provides a binding site for dna signalling proteins, hormones, enzymes, etc. to bind to which can switch the gene on or off.
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promotors don't themselves regulate gene expression
instead: it provides a binding site for dna signalling proteins, hormones, enzymes, etc. to bind to which can switch the gene on or off.
In my notes which I wrote and I remember hearing/reading it from some source, promoters (quote from my notes) 'Are involved in regulating and in some sense the expression of a gene'. But I also have another definition which states that it 'helps with the initiation of transcription - RNA polymerase attaches itself to it during transcription.
I recall that a promoter can be placed in plasmids (etc.) as well to help regulate genes. But I'm not sure if these promoters are the same or the name for another aspect that is involved in that case as above (plasmids).
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does anyone know how to do Q10 of MC from biol exam 2005.
Look at the offspring give. Recognise that there are two classes, recombinants and parentals. It's implied that the dwarf/pear plant was homozygous recessive, so only the gametes of the heterozygote matter.
Based on the numbers, parentals are tall/pear and dwarf/spherical
Thus the arrangement on the parental chromosome must be:
Dp
__
dP
Therefore, B
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promotors don't themselves regulate gene expression
instead: it provides a binding site for dna signalling proteins, hormones, enzymes, etc. to bind to which can switch the gene on or off.
In my notes which I wrote and I remember hearing/reading it from some source, promoters (quote from my notes) 'Are involved in regulating and in some sense the expression of a gene'. But I also have another definition which states that it 'helps with the initiation of transcription - RNA polymerase attaches itself to it during transcription.
I recall that a promoter can be placed in plasmids (etc.) as well to help regulate genes. But I'm not sure if these promoters are the same or the name for another aspect that is involved in that case as above (plasmids).
im 100% sure that the promotor provides a binding site, and what you've said above is exactly what im talking about because e.g. with the plasmid thing, the transgene will not be transcribed without the promotor because the promotor provides the binding site of which RNA polym. can bind to initiating transcription.
if that makes sense lol :)
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Maybe back then as I was writing the notes I had heard that promoters can act as regulators as a mutated promoter can stop gene expression. Thanks for the explanation.
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ummm my definition of a promoter - non coding base sequences that signal the start of the signal, thus the binding site for RNA polymerase.
correct me if im wrong (:
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binding of proteins like transcription factors etc can regulate transcription by binding to promoter regions or near them but the actual promoter sequence doesn't do anything unless something binds to it ...
but yes the promoter is where the rna pol binds ... and yes in eukaryotes you need different transcription factors to bind to different regions of the promoter for rna pol to bind...
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dna binding proteins are only in eukaryotes however
whereas in prokaryotes to regulate genes they have repressor molecules as seen in the lac operon
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They have other types of moderation as well, the lac operon is just one example
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hence the e.g. ;)
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Your post doesn't have an e.g. in it, it sounds as if repressors are the only system
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only found in eukaryotes?
dna binding protein= a protein that binds to dna
whats a repressor protein?
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i meant eg. by as seen :)
and repressor proteins are molecules such as tryptophan, you dont need to know their names specifically, it will be given in the question
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tryptophan molecules are the corepressor
trp repressor is the repressor