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    I know we have to recognise the distinguishing features of the five kingdoms. But, I am revising evolution (page 101 in NAS), and there's a question 'what features do trilobytes show which enable them to be classified as arthropods?'.. do we have to know how to tell which groups organisms belong to, and characteristics of groups like annelida, cnidarians etc?
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    nope, i really doubt it

    just learn the five kingdoms and Kingdom, Phylum, Class, Order, Family, Genus, Species
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    You will have to know the characteristics for the 5 knigdoms (animalia, plantae and so on) but not the sub-phylum e.g annelida and so on.
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    the protoctista kingdom... just random eukaryotic organisms that aren't plants, animals or fungi, such a rubbish system!
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    fantastic.

    So, anyone else still got half of unit 5 to cover, or is that just me?
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    yeah same here, i need to spend time on genetics, photosynthesis and the classfication and population stuff is fine. Im trying to make sure i know what everything means.

    How long did it take you revise for unit 5??
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    In the specification, for Gene Technology, there is something about explaining how the synthesis of proteins coded for by recombinant DNA is brought about. But there's nothing about this in the textbook -help! I still have a lot of synoptic revision to do and I just don't get the conservation chapter is trying to explain - I'm so stressed!
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    Where in the specification fr gene technology doe it say something explaining how the synthesis of proteins coded for by recombinant DNA is brought about??/
    What board is this???
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    Conservation is the process of maintaing an ecosystem in order to retain maximum species diversity. this involves careful use of the earth's natural resources in order to avoid gradual destruction of the environments by human activities. It also involves preservation of natural habitats and an awareness of the dangers of pollution.

    Coppicing =

    Tress can be coppuices for timber, that is they can be cut down to the base from which they are allowed to regrow for several years before being coppiced again. Different parts of the worrd are coppices each year, in rotation. A coppices woodland is likey to have a grater biodiversity than one in which the tress are not cut down at all, becuase he rotational coppicing provides a range of different habitats, in which different species of plants and animals live.

    Even though buring tree using fire, may cause CO2 be relasesd, but the amount released is basically the amount taken up by the plants. In addtion using fire produces ashes which left on the ground, bring nutrients to the soil. But fire can be a danger to animals which are unable to get away.

    Farming=
    Farming allows fertislieser to be added to the soil which brings nutrients for plants but can flost into the rivers and lakes and cause eutrophication. Also the land will be irrgated, so the enviroment where the land is stitutated produces a low rainfall but is just enough for some crops to be grown. will get more water from the irrigation.

    You got grazing, trampling and all that stuff. More food more animals but differnet varity of food, differnet varity of animals, so biodiversity increases.

    Hope i helped!!!
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    edexcel right? i finished all my notes for unit 5 today, now just need to keep going through them till tuesday, the unit is not that hard, all the chapters between photosynthesis and gene technology seem common sense
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    It says understand how synthesis of the new protein is 'switched on'. This is different to how the new protein is synthesised (which should be part of your synoptic revision on translation - thats all the ribosome bit). To be honest, i don't know how it is switched on - i guess you need to understand what the modified plasmid does after it has been injected.

    Somebody...help!

    And synoptic revision doesnt take that long. Remember, in Unit 5, almost all of the synoptic stuff will have some link to unit 5. Ecosystems (food chains etc) and the nitrogen and carbon cycles are big, enzymes (their industrial application and how they are denatured + inhibited), the DNA stuff i mentioned earlier and digestion. Trust me, once you've looked at it again, it will all come flooding back!
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    If you look at the spcification it says "understand how protein synthesis is switched on and the syntheses of a new product by the host cells ilustration by the production of new genes into plans using agrobactrium".

    Well its basically asking you the gene is made - Using reverse transcriptase
    And how to transfer the gene into a bactrial cell, in this case agrobactrium - using plasmids from the bacters, cutt plasmid to expose sticjy ends , incubate the plasmid with the dna made form the gene and adding DNA ligase to join all the pecies of DNA up, and then incubatting the plasmid with the bacteria. Then using the marker gene to identify which helps have taken up the plasmid and which have not. So he ones that have can be cultured.
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    Well Thats What I Think It Is
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    surely the 'start codon' switches it on?! The ribosome attaches to the start codon then moves along the mRNA three bases at a time, appropriate amino acids are brought to the ribosome by specific molecules of tRNA and the ribosome joins these together to make a protein.

    reading what everyone's written has really confused me, maybe this isn't relavant?
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    I found this on the net but does it make sense??

    How is protein synthesis in bacteria switched on?

    If the protein is an enzyme and the bacteria are being grown in a fermenter, then the addition to the medium of the substrate for that enzyme will result in the synthesis of the enzyme by the bacteria.
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    (Original post by kohlstream)
    fantastic.

    So, anyone else still got half of unit 5 to cover, or is that just me?
    Yeh i have Must Revise!!!! :eek:
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    (Original post by KP Nuts)
    It says understand how synthesis of the new protein is 'switched on'. This is different to how the new protein is synthesised (which should be part of your synoptic revision on translation - thats all the ribosome bit). To be honest, i don't know how it is switched on - i guess you need to understand what the modified plasmid does after it has been injected.

    Somebody...help!

    And synoptic revision doesnt take that long. Remember, in Unit 5, almost all of the synoptic stuff will have some link to unit 5. Ecosystems (food chains etc) and the nitrogen and carbon cycles are big, enzymes (their industrial application and how they are denatured + inhibited), the DNA stuff i mentioned earlier and digestion. Trust me, once you've looked at it again, it will all come flooding back!
    Theres about 6sides based on unit 5 ( :mad: ) and then the synoptic, last year, wasn't very linked to it at all, it included one question (12 marks) on older women and IVF... and why it wasn't always successful :confused:
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    Recombinant DNA is taken into Agrobacterium Tumerfaciens

    Test for marker genes (e.g. antibiotic resistance) in Agrobacterium Tumerfaciens to test whether the recominant DNA has been taken into plant

    Agrobacterium Tumerfaciens infects plant and causes it's desired gene to be placed in the plants DNA

    Therefore, causing a transgenic (GM) plant to be produced

    This ISNT the end of the story though...

    Gene expression occurs because an inhibitor bind to the repressor protein produced by the regulator gene

    This causes the operator gene not to be blocked, therefore hydrogen bonds in the promoter and structural genes break

    This causes the double stranded DNA to become single stranded DNA where the gene is present

    Free RNA nucleotides in the nucleus of the plant cell to form complimentary bonds to the sense strand of DNA catalysed by RNA polymerase

    The RNA nucleotides form sugar-phosphate bonds, forming a mRNA polypeptide

    Adenine-Tail and Guanine Cap are added and introns are removed

    The RNA travels through the nuclear pore of the nucleus

    Is translated at ribosomes in the RER

    This produces the polypeptide, which is then transported to the Golgi Apparatus where the protein is repacked and modified

    The gene is only expressed if it is translated into a protein, there would be absolutely no point in placing the desired genes into an organism if they weren't expressed.
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    (Original post by b_shaikha4321)
    If the protein is an enzyme and the bacteria are being grown in a fermenter, then the addition to the medium of the substrate for that enzyme will result in the synthesis of the enzyme by the bacteria.
    This is because the inhibitor in this case is the substrate.

    E.g. lactose can act as a inhibitor

    When there is no lactose

    The regulator gene produces a repressor protein

    This binds to the operator gene

    Preventing gene expression

    However, when the inhibitor is present, in this case it is lactose,

    The lactose binds to the repressor protein

    This means that the operator gene isn't blocked

    This means that hydrogen bonds in the promotor and structural genes are broken

    mRNA is formed as described above

    mRNA is translated at the ribosome

    this means that the enzyme that hydrolyses lactose is produced

    therefore, genes are only expressed when they are needed
 
 
 
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