Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    Offline

    2
    ReputationRep:
    Can someone give me a link to the old last papers?
    Offline

    2
    ReputationRep:
    please can someone explain genetic drift?
    Offline

    10
    ReputationRep:
    (Original post by Student23478)
    Can someone give me a link to the old last papers?
    thebiotutor.com has all the past papers


    Posted from TSR Mobile
    Offline

    10
    ReputationRep:
    (Original post by baymax96)
    I'm literally cramming the whole syllabus today. obvs going to fail
    what should I focus on:/
    Focus on the topics that you struggle with


    Posted from TSR Mobile
    Offline

    2
    ReputationRep:
    what's the usual grade boundary for an A/a*?
    Offline

    2
    ReputationRep:
    Revising F215 in a day ... Impossible ???
    Offline

    2
    (Original post by baymax96)
    what's the usual grade boundary for an A/a*?
    65ish for an A and 135/150 UMS (A*) is around 6 marks above the A boundary...so 71ish?
    Offline

    2
    ReputationRep:
    (Original post by invictus212)
    Revising F215 in a day ... Impossible ???
    I so feel your pain my friend
    Offline

    2
    ReputationRep:
    (Original post by Smilesison123)
    65ish for an A and 135/150 UMS (A*) is around 6 marks above the A boundary...so 71ish?
    65/100 for an A?
    Offline

    2
    ReputationRep:
    (Original post by baymax96)
    I so feel your pain my friend
    A part of me is saying no point wasting my time, another part of me is saying you can do the impossible LOL 😂

    Nah, we can do this guys.., as long as we just fit in a ton of past papers and don't sleep Tbf.
    Offline

    2
    (Original post by baymax96)
    65/100 for an A?
    Yeah. If you look at all past gradeboundaries they range from 63/100 to 77/100 ( but that was the highest) usually it's in the 60's
    Offline

    2
    ReputationRep:
    (Original post by invictus212)
    A part of me is saying no point wasting my time, another part of me is saying you can do the impossible LOL 😂

    Nah, we can do this guys.., as long as we just fit in a ton of past papers and don't sleep Tbf.
    which papers will you do?
    Offline

    10
    ReputationRep:
    (Original post by baymax96)
    please can someone explain genetic drift?
    Change in allele frequency in a population brought about by chance.

    For instance, if a there was a population of grey and black mice in a habitat, and a flood occurred and only one black mouse survived and all the grey mice survived, this is genetic drift.
    The reason:
    The flood caused a change in allele frequency as it removed most of the mice with the allele for black coat colour.
    The flood removed most of the black mice by CHANCE, not on purpose.
    Due to only one black mouse being left, and there being more grey mice, all the mice are likely to interbreed to give offspring that are grey, not black, since there are more grey mice to start with.

    The smaller the population size, the larger the effect of genetic drift. Genetic drift can reduce genetic variation (as one allele is significantly more common than the other), and as a result, can lead to the extinction of the species with the less common allele.

    Hope that wasn't too waffly!
    Offline

    2
    ReputationRep:
    (Original post by coolerthanbeans)
    Change in allele frequency in a population brought about by chance.

    For instance, if a there was a population of grey and black mice in a habitat, and a flood occurred and only one black mouse survived and all the grey mice survived, this is genetic drift.
    The reason:
    The flood caused a change in allele frequency as it removed most of the mice with the allele for black coat colour.
    The flood removed most of the black mice by CHANCE, not on purpose.
    Due to only one black mouse being left, and there being more grey mice, all the mice are likely to interbreed to give offspring that are grey, not black, since there are more grey mice to start with.

    The smaller the population size, the larger the effect of genetic drift. Genetic drift can reduce genetic variation (as one allele is significantly more common than the other), and as a result, can lead to the extinction of the species with the less common allele.

    Hope that wasn't too waffly!
    thank you!! I've reached my rep limit otherwise I would've given you 😁
    Offline

    2
    ReputationRep:
    (Original post by baymax96)
    which papers will you do?
    Idk yet, which ones are the hardest mate ?! 😔 well... I'll probably end up doing every june paper for the past 4 years or something.
    Offline

    2
    ReputationRep:
    is there like a list of different enzyme functions? I get confused with rna polymerase and DNS polymerase and then reverse transcriptase etcetc
    Offline

    2
    ReputationRep:
    (Original post by invictus212)
    Idk yet, which ones are the hardest mate ?! 😔 well... I'll probably end up doing every june paper for the past 4 years or something.
    aahhh ok, I'm not sure whether to revise material and cram or just do papers:/
    Offline

    1
    ReputationRep:
    (Original post by raach.14)
    Voluntary (skeletal) - movement of limbs
    Cardiac - contraction of the heart/pump blood
    involuntary (smooth) - something to do with autonomic control but I know this isn't specific enough, if someone could add that would be great!
    Contraction of the cicular muscles in the eye constricts the pupil
    Contraction of smooth muscles in the arteries constricts the lumen

    Posted from TSR Mobile
    Offline

    2
    ReputationRep:
    (Original post by baymax96)
    aahhh ok, I'm not sure whether to revise material and cram or just do papers:/
    You'll have to do both in all honesty... With the limited time we have. You can't really not now the material cuz they're asking odd questions on these exams lately.

    Let's just do this man!!!!!!!! 😂🙏
    Offline

    5
    ReputationRep:
    (Original post by baymax96)
    is there like a list of different enzyme functions? I get confused with rna polymerase and DNS polymerase and then reverse transcriptase etcetc
    Clue is normally in the name I.e.
    - Reverse transcriptase - Transcription in reverse (Transcription of RNA to make DNA)
    - The polymerase -makes polymers of the corresponding name, so dna polymerase makes dna
    Then you get the few odd ones;
    - Restriction enzymes - cut dna at a specific points to isolate the section of dna (in the desired gene)
    -Dna ligase - Anneals the cut dna from desired gene into a plasmid/vector (thats also been cut with the same restriction enzyme)
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: June 3, 2016
Poll
Do you agree with the proposed ban on plastic straws and cotton buds?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.