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  1. S

    AS Chemistry P2 Prep.

    ohh yeah got my mistake! thanks :)
  2. S

    AS Chemistry P2 Prep.

    okay its kinda weird but i cant get this question right..the answer is 18..im getting 14..
  3. S

    A2 Biology | Post your doubts here

    are you guys doing the application part frm ocr or the booklet..or both? :P i dont have much time so where should i do it frm?
  4. S

    A2 Biology | Post your doubts here

    thank you :) i have some other confusions that i"ve posted some time back..probably on the previous page..plz see if you could help me out with them! thanks again. will surely remember you in my prayers :)
  5. S

    A2 Biology | Post your doubts here

    crossing over occurs between non sister chromatids of homologous chromosomes yeah?
  6. S

    A2 Biology | Post your doubts here

    got it!thanks :)
  7. S

    A2 Biology | Post your doubts here

    Explain why variation is important in selection; 1. ref. continuous / discontinuous variation ; 2. genetic / inherited variation ; 3. variation in phenotype / characteristics / AW ; 4. (can be due to) interaction of genotype and environment ; 5. e.g. of...
  8. S

    A2 Biology | Post your doubts here

    Explain how natural selection may bring about evolution; 1. individuals in population have great reproductive potential / AW ; 2. numbers in population remain roughly constant ; 3. variation in members of population ; 4. environmental factors / named factor (biotic or...
  9. S

    A2 Biology | Post your doubts here

    people homozygous for sickle cell allele die because of it. those heterzygous are less likely to suffer frm an attack of malaria than those homozygous for the normal allele. thats whats the book says. are we supposed to know why?
  10. S

    A2 Biology | Post your doubts here

    i read it in ocr but they havent given an explanation for it..if you have the book its selection n evolution.pg 251-2. its there in the revision guide too!
  11. S

    A2 Biology | Post your doubts here

    thankss!
  12. S

    A2 Biology | Post your doubts here

    people homozygous for normal Beta polypeptide allele are less likely to have malaria..why?
  13. S

    A2 Biology | Post your doubts here

    please explain how are the daughter cells different from each other..i dont get independent assortment of chromosomes. there are 2 which are same..the top one and the one right below it are same yeah?
  14. S

    A2 Biology | Post your doubts here

    are we expected to know details of any other receptor other than pacinian corpuscle?
  15. S

    A2 Biology | Post your doubts here

    ohh right. thanks a lot! peritubular capillaries provide the blood supply to loop of henle. what abt vasa recta?
  16. S

    A2 Biology | Post your doubts here

    in the loop of henle..Na and Cl ions diffuse out of the ascending limb into the space between the two limbs. water moves via osmosis frm descending limb into the tissue fluid. Na and Cl ions due to their higher conc move into the descending limb. so how is the tissue fluid more concentrated as...
  17. S

    A2 Biology | Post your doubts here

    in the loop of henle..Na and Cl ions diffuse out of the ascending limb into the space between the two limbs. water moves via osmosis frm descending limb into the tissue fluid. Na and Cl ions due to their higher conc move into the descending limb. so how is the tissue fluid more concentrated as...
  18. S

    A2 Biology | Post your doubts here

    i cant download it..if i click the download option it opens up some warning. help plz?
  19. S

    A2 Biology | Post your doubts here

    guys..any good notes that i can go over in a day?
  20. S

    A level Biology: Post your doubts here!

    assalamoalaikum. i just wanted to know if you have other notes like these for other chapters? it"ll be of great help if you post them up or give me the link if you"ve already done so! thanks :)
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