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    Do we need to know how the specific structure of sarcomere changes when the muscle contracts?

    Thanks
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    do we need to know about troponin and f actin?
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    (Original post by rebeccalouise_92)
    the insulin gene in the plasmid breaks the tetracycline resistance, so this means that the bacteria that takes up this plasmid will not grow on tetracycline as it is not resistant to it! so it will only grow on ampicillin, therefore we only want this bacteria
    thankks

    is there any reason why we break the tetracycline resistance and not the ampicillin?
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    (Original post by thecookiem0nster)
    Reverse transcriptase is used to produce mRNA from DNA. So, it does the opposite of transcription. Its used in genetic engineering, when an mRNA strand for a gene has been isolate (e.g. insulin) then, it is possible to produce the corresponding DNA for insertion into a plasmid

    Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. it allows them to exchange genes for resistance. ect.
    Reverse transcriptase is a DNA polymerase enzyme that transcribes a single stranded RNA into a double stranded DNA.

    I wouldn't worry too much about this since it was a question in the Jan paper I think.
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    (Original post by thecookiem0nster)
    For sympatric speciation, you need distruptive selection to occur. I saw a legacy exam question where they had seahorses who were either big or small. They were undergoing distruptive selection and had formed seperate species in the same area. If a big seahorse and small seahorse had medium sized offspring, the medium sized offspring had a selective disadvantage. So the population eventually seperated so much into big and small that there was very little exchange of alleles. Therefore speciation had occured as they were no longer able to produce fertile offspring

    biotic environmental pressures:
    Competition - Interspecific and intraspecific
    Availability of prey to eat
    Diseases or infecting bacteria
    Parasites

    abiotic pressures:
    Temperature
    Water availability
    Nitrates in the soil
    Wind
    Light
    Thanks, that's a great and memorable example.

    And thanks for the abiotic and biotic, too
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    (Original post by MoMatrix)
    do we need to know about troponin and f actin?
    We do need to know troponin, and how it functions as it was in a mark scheme for a legacy paper that asked about the sliding filament model

    Yeah, we need to know about f-actin although you dont need to refer to it with the "f"
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    (Original post by 786girl)
    is this correct?
    hydrolysis of ATP = breaks crossbridge?
    Yeah, ATP is hydrolysed to break the cross bridge between myosin and troponin
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    (Original post by thecookiem0nster)
    Reverse transcriptase is used to produce mRNA from DNA. So, it does the opposite of transcription. Its used in genetic engineering, when an mRNA strand for a gene has been isolate (e.g. insulin) then, it is possible to produce the corresponding DNA for insertion into a plasmid

    Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. it allows them to exchange genes for resistance. ect.
    doesn't it produce a single strand of DNA (cDNA) from mRNA? sorry just worried now aha
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    (Original post by MoMatrix)
    do we need to know about troponin and f actin?
    Yes.
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    (Original post by thecookiem0nster)
    Reverse transcriptase is used to produce mRNA from DNA. So, it does the opposite of transcription. Its used in genetic engineering, when an mRNA strand for a gene has been isolate (e.g. insulin) then, it is possible to produce the corresponding DNA for insertion into a plasmid

    Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. it allows them to exchange genes for resistance. ect.
    And RNA goes to cDNA through the use of reverse transcriptase, too
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    (Original post by SR198198)
    1. Lac Operon
    2. Apoptosis
    3. Chi squared test
    4. Hardy Weinberg Equations
    5. Differences and similaries between natural and artificial selection
    6. Genetic Drift
    7. Advantages disadvantages of plant cloning
    8. Immobilisation of enzymes
    9. Electrophoresis
    10. PCR
    11. The Brain, structure and so on
    12. Dopamine and the DRD4 receptor.

    May be wrong tho man, but yeah hope that helps.
    Didnt that Dopamine DRD4 stuff come up in a recent paper???
    oh i hope that dont come up.. i dont get it
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    what do you think the 2 LONG (10marks usually) QuestioNS will be on????????????????????????????
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    (Original post by althornber1)
    doesn't it produce a single strand of DNA (cDNA) from mRNA? sorry just worried now aha
    Thats right, it does make the single strand of cDNA. The single strand can be made double by DNA transcriptase. Sorry for making it a bit unclear
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    (Original post by miss-pink09)
    thankks

    is there any reason why we break the tetracycline resistance and not the ampicillin?
    yes because the binding site for the insulin gene is bang in the middle of the tetracycline resistant gene ! not the ampicillin. so ampicillin resitance remains
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    (Original post by Waqar Y)
    I don't think you'll need to know bacterial conjugation but reverse transcriptase is used to produce a DNA strand in the host cell. It basically takes RNA and changes it to DNA.
    Why would you need to do that? or What would do that?
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    (Original post by thecookiem0nster)
    Thats right, it does make the single strand of cDNA. The single strand can be made double by DNA transcriptase. Sorry for making it a bit unclear
    Damn! i got it the wrong way round lol... sorry
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    (Original post by rebeccalouise_92)
    yes because the binding site for the insulin gene is bang in the middle of the tetracycline resistant gene ! not the ampicillin. so ampicillin resitance remains
    ahh you guys are genius' i love youuuuuuuu <3 haha
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    (Original post by Waqar Y)
    Crossing over in prophase 1 would give different allele combinations e.g could have a bit of chrosome 2 swapped with another bit of chromosome 2.

    Random assortment of bivalents/chrosomosomes during metaphase 1

    Random assortment of chromatids during metaphase 1

    Fertilization is random too.

    Even interphase, DNA replication - can go wrong and produce variation > but it's a bit too much i think
    mutation too
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    quick question on subdivision of the nervous system - does peripheral split into sensory and motor, then motor splits into somatic and autonomic? not sure about the sensory/motor part
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    Looking forward to 3.30 when this exam will be over
 
 
 
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