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  1. I

    A level Biology: Post your doubts here!

    Any discussions for P41?
  2. I

    A level Biology: Post your doubts here!

    I really have no idea. Dad's Egyptian, mum's Jordanian. I'm living in Jordan right now, but I was raised up all over the world :P
  3. I

    A level Biology: Post your doubts here!

    My exam was great. I loved the questions - they really stimulated my thinking. I'm expecting any mark above 95 insha2allah :)
  4. I

    A level Biology: Post your doubts here!

    I appreciate your compliments, but I'm not Paki nor Indian :P
  5. I

    A level Biology: Post your doubts here!

    As far as I know, foot = podocyte Also, it's really rare to find 2006 questions in the new syllabus; there's a completely different form of questions now.
  6. I

    A level Biology: Post your doubts here!

    1) The food web only contains organisms, not abiotic factors such as sunlight, nutrient levels, and oxygen concentrations. 2) If the substrate concentration is high, then there will be a much higher chance that the enzyme would bind to the substrate rather than the (competitive) inhibitor. If...
  7. I

    A level Biology: Post your doubts here!

    If a stimulus is strong enough to exceed a certain threshold, it will stimulate the formation of an action potential in the sensory neurones. It will travel along the axon through the dorsal root of the spinal nerve where it will synapse with an intermediate/relay neurone. Rather than allowing...
  8. I

    A level Biology: Post your doubts here!

    1) We know that along food chains, the biomass decreases (roughly 10% is transferred to the next trophic level) To find the total biomass of a population, multiply the number of individuals by the biomass of one individual R: 10,000 x 0.1 = 1,000 S: 5 x 10.0 = 50 T: 500 x 0.002 = 1 U: 3 x...
  9. I

    A level Biology: Post your doubts here!

    I don't really know what am I supposed to explain exactly. They tell you in the question that the "tagged/labelled" nucleotides are present in low concentrations, so there's only a very small chance that they will be present in the first locus (spot).
  10. I

    A level Biology: Post your doubts here!

    We know that there is lack of oxygen. If there wasn't any lack of oxygen, then anaerobic respiration wouldn't have started in the first place. Oxygen debt is how much oxygen you need to break down the toxic products (lactic acid) of anaerobic respiration. The longer anaerobic respiration has...
  11. I

    A level Biology: Post your doubts here!

    The oxygen required to metabolize/use up the lactic acid produced (or respire it completely)
  12. I

    A level Biology: Post your doubts here!

    Seriously, I don't mind doing some math right here. You can inbox me your scores if you prefer some privacy
  13. I

    A level Biology: Post your doubts here!

    I don't mind, do you have an A in your AS already?
  14. I

    A level Biology: Post your doubts here!

    Okay, let's say you're sick, so you need to take an antibiotic. We know that antibiotics are useless if bacteria are resistant to it. During the process of genetic engineering, we made plasmids that have an antibiotic-resistant allele. If you take insulin that's made from these plasmids, then...
  15. I

    A level Biology: Post your doubts here!

    Sorry, I made a mistake right there. I meant to say that the minimum score for a B in paper 3 was a 22/40, and for paper 5 was an 18/20. So that means you're supposed to get 154 in the remaining components. So if you get a 30/40 in Paper 1, 50/60 in Paper 2, and 75/100 in Paper 4, then you...
  16. I

    A level Biology: Post your doubts here!

    This isn't easy to explain, so I'll try to provide an example: Remember when you're trying to mass-produce insulin, you had to use 2 different types of antibiotics to see which bacteria took up the plasmids? If you just happen to be sick at the same time (while being diabetic and taking...
  17. I

    A level Biology: Post your doubts here!

    I think it's still possible to get an A* EDIT: Let's take a look at the most recent session available (Oct/Nov 2012): During that session, the minimum score for a B was 32/60, and the minimum score for a B in paper 5 was 18/30. The A* threshold was 194/260. Subtracting the scores you already...
  18. I

    A level Biology: Post your doubts here!

    Photorespiration is when oxygen binds with RuBP instead of carbon dioxide in the Calvin Cycle (light-independent reactions, according to the A2 book) The light independent reactions require a lot of ATP. When carbon dioxide enters the Calvin Cycle, the ATP (along with NADPH) is used to produce...
  19. I

    A level Biology: Post your doubts here!

    http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Biology%20(9700)/9700_nos_as_1.pdf http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Biology%20(9700)/9700_nos_as_2.pdf...
  20. I

    A level Biology: Post your doubts here!

    From what I know, the endodermal cells of sorghum have a high silica content which is thought to provide drought resistance.
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