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    What time is the exam, AM or PM? My friends in my class are NOT responding
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    (Original post by SKK94)
    They're bald because they live in hot conditions, so they don't need fur to keep them warm.

    I'm not sure but wrinkles could make their skin more tough and resistant to damage as they dig tunnels and encounter rocks etc.

    hehe...thanks...
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    (Original post by rudizzy123)
    What time is the exam, AM or PM? My friends in my class are NOT responding

    dont u have a time table?
    its pm
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    (Original post by SKK94)
    They're bald because they live in hot conditions, so they don't need fur to keep them warm.

    I'm not sure but wrinkles could make their skin more tough and resistant to damage as they dig tunnels and encounter rocks etc.

    btw, thats anatomial adaptations, isnt it?
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    (Original post by iwantopas19)
    dont u have a time table?
    its pm
    Thanks, it's my last exam, and I knew when it was so foolishly threw it away.

    I am currently resitting this unit, I have been getting a* in all the past papers (as i did last year) but last year, June 2012 was absoloutley ridiculous and featured next to NO biology in it, I was crushed and got a D, an anomoly for me, hopefully, as long this paper is a normal biology paper, I should be fine
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    (Original post by rudizzy123)
    Thanks, it's my last exam, and I knew when it was so foolishly threw it away.

    I am currently resitting this unit, I have been getting a* in all the past papers (as i did last year) but last year, June 2012 was absoloutley ridiculous and featured next to NO biology in it, I was crushed and got a D, an anomoly for me, hopefully, as long this paper is a normal biology paper, I should be fine

    I really hope so, but all papers are really weird and sick this time. but wish u all the best
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    (Original post by iwantopas19)
    btw, thats anatomial adaptations, isnt it?
    Yeah.
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    Can someone pls explain why after a few hours in darkness, Pfr will convert slowly back to Pr... also, is Pr formed through enzymes thus cause flowering in plants? i thought flowering only happens when there is Pfr. correct me if i am wrong. thanks
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    Hi can someone tell me why endemic species are vulnerable to changes in environment? thanks
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    (Original post by Soul_Eater)
    Hi can someone tell me why endemic species are vulnerable to changes in environment? thanks
    Hi it's because they don't have large number of organisms in the population so not many alleles which means low genetic variation. With low genetic variation fewer mutations occur so cannot adapt efficiently. And basically over time the selection pressure will become too much and they'll become extinct

    Posted from TSR Mobile
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    (Original post by bubblegummer)
    Can someone pls explain why after a few hours in darkness, Pfr will convert slowly back to Pr... also, is Pr formed through enzymes thus cause flowering in plants? i thought flowering only happens when there is Pfr. correct me if i am wrong. thanks
    in long night plants Pfr inhibits flowering - they need Pr to do so, Pfr only triggers flowering in short night plants.
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    (Original post by rudizzy123)
    Thanks, it's my last exam, and I knew when it was so foolishly threw it away.

    I am currently resitting this unit, I have been getting a* in all the past papers (as i did last year) but last year, June 2012 was absoloutley ridiculous and featured next to NO biology in it, I was crushed and got a D, an anomoly for me, hopefully, as long this paper is a normal biology paper, I should be fine
    :'( when i did that paper i thought i m the dumbest person in this world... the questions were so lame and not even related to a level biology :'(
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    i don't j=know how to analyse ventilation graph and cacluate ventilation rate can someone help me please
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    If you want to do any targeted revision (according to a sheet my teacher gave me, that might not be 100% accurate):

    Topics that came up in January 2013:
    - Joints/antagonistic muscles
    - Glycolysis, Krebs cycle, electron transport chain/chemiosmosis
    - Control of heart rate & cardiac output
    - The effect of exercise/spirometers
    - Negative feedback/homoeostasis/thermoregulation
    - Keyhole surgery
    - Photoreceptors
    - Impulse/transmission of action potentials
    - Synapses (eg. inhibitory/excitatory)
    - The brain (which bit does what)
    - Drugs from GMOs
    - Benefits/risks of GMOs

    Things that haven't come up in 2 years+ (Jan 2010 - Jan 2013):
    - Muscle fibres (slow/fast twitch)
    - Sliding filament theory
    - ATP
    - The fate of lactate
    - ECG
    - Transcription factors
    - Effects of too much/little exercise
    - The ethics of performance enhancing drugs
    - Neurones
    - Nerves vs hormones
    - Nature vs nurture in brain development
    - Habituation
    - The habituation practical (has never come up)
    - Ethics of animals in research
    - Parkinson's/depression
    - Drugs & synpases

    Things that have come up 4x + (Jan 2010 - Jan 2013):
    - Joints/antagonistic muscles: 5 times
    - Glycolysis: 4 times
    - Photoreceptors: 4 times
    - The brain: 4 times

    Things that have come up once/twice (Jan 2010 - Jan 2013):
    - Risks/benefits of GMOs
    - Drugs from GMOs
    - Drug development/HGP
    - Drugs & synapses (this is on the spec :confused:)
    - Parkinson's/depression
    - Ethics of animal research
    - Habituation
    - Critical windows for vision/nature nurture/brain development
    - Brain imagining
    - Nerves vs hormones
    - Pupil reflex
    - Retina as a receptor
    - Neurones & synapses
    - Ethics of drug use
    - Too much/little exercise (has never come up)
    - Transcription factors (has never come up)

    - Negative feedback/homoeostasis/thermoregulation
    - ECGs
    - Fate of lactate
    - ETC/Chemiosmosis
    - Krebs cycle
    - ATP
    - Rate of respiration core practical

    Let your inner fortune-teller go wild!
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    (Original post by bubblegummer)
    Can someone pls explain why after a few hours in darkness, Pfr will convert slowly back to Pr... also, is Pr formed through enzymes thus cause flowering in plants? i thought flowering only happens when there is Pfr. correct me if i am wrong. thanks

    in darkness there is more far red light than red light. therefore PFR is converted to PR. to maintain the equilibirum.
    yeah u are right PR is inactive it inhibits flowering whereas PFR is active and causes germination and flowring
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    For seed germination, do we need Pfr only??
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    (Original post by Nilie)
    do you mean the rods or the plants and phytochromes?
    The rods, sorry I should have made that clearer
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    (Original post by Chocip)
    If you want to do any targeted revision (according to a sheet my teacher gave me, that might not be 100% accurate):

    Topics that came up in January 2013:
    - Joints/antagonistic muscles
    - Glycolysis, Krebs cycle, electron transport chain/chemiosmosis
    - Control of heart rate & cardiac output
    - The effect of exercise/spirometers
    - Negative feedback/homoeostasis/thermoregulation
    - Keyhole surgery
    - Photoreceptors
    - Impulse/transmission of action potentials
    - Synapses (eg. inhibitory/excitatory)
    - The brain (which bit does what)
    - Drugs from GMOs
    - Benefits/risks of GMOs

    Things that haven't come up in 2 years+ (Jan 2010 - Jan 2013):
    - Muscle fibres (slow/fast twitch)
    - Sliding filament theory
    - ATP
    - The fate of lactate
    - ECG
    - Transcription factors
    - Effects of too much/little exercise
    - The ethics of performance enhancing drugs
    - Neurones
    - Nerves vs hormones
    - Nature vs nurture in brain development
    - Habituation
    - The habituation practical (has never come up)
    - Ethics of animals in research
    - Parkinson's/depression
    - Drugs & synpases

    Things that have come up 4x + (Jan 2010 - Jan 2013):
    - Joints/antagonistic muscles: 5 times
    - Glycolysis: 4 times
    - Photoreceptors: 4 times
    - The brain: 4 times

    Things that have come up once/twice (Jan 2010 - Jan 2013):
    - Risks/benefits of GMOs
    - Drugs from GMOs
    - Drug development/HGP
    - Drugs & synapses (this is on the spec :confused:)
    - Parkinson's/depression
    - Ethics of animal research
    - Habituation
    - Critical windows for vision/nature nurture/brain development
    - Brain imagining
    - Nerves vs hormones
    - Pupil reflex
    - Retina as a receptor
    - Neurones & synapses
    - Ethics of drug use
    - Too much/little exercise (has never come up)
    - Transcription factors (has never come up)

    - Negative feedback/homoeostasis/thermoregulation
    - ECGs
    - Fate of lactate
    - ETC/Chemiosmosis
    - Krebs cycle
    - ATP
    - Rate of respiration core practical

    Let your inner fortune-teller go wild!
    I WOULD KISS YOU but that would be totally homo, so I'm just going to +1 rep you once I get them back ha. Thank you!
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    (Original post by ayat94)
    i don't j=know how to analyse ventilation graph and cacluate ventilation rate can someone help me please

    can u be more specific? what is that u dont know?

    1st of all know this, rate at which someone breath is called ventilation rate (vol of air breathed/min)

    -volume of air breathed in or out of lungs per breath is called tidal volume-the maximum volume of air that can be forcibly exhaled after a maximal intake of air is caled vital capacity.

    ventilation rate= tidal volume x number of breath/min.


    -to measure tidal volume ...just measure the height from peak to trough on the trace.
    the breathing rate would be the time between one P wave to other.

    then just substitute in the formula.


    guess this helps
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    (Original post by bubblegummer)
    Can someone pls explain why after a few hours in darkness, Pfr will convert slowly back to Pr... also, is Pr formed through enzymes thus cause flowering in plants? i thought flowering only happens when there is Pfr. correct me if i am wrong. thanks
    Pfr actually doesn't exist in visible light my teacher said. It can only be made in lab conditions. Visible light goes up to 660nm maximum (which is Pr).
    Pfr is unstable so it breaks down back to Pr when there is no more visible light to keep the conversion of Pr to Pfr going. T
    Flowering happens when there is sufficient enough Pfr but depends on the plants, some need a lot others not as much.


    Posted from TSR Mobile
 
 
 
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