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  1. Z

    Biology Practical notes!!

    What are the definitions of these terms: 1. Complete plasmolysis 2. Cap plamolysis 3. Plasmodesmata plasmolysis 4. Cap and plasmodesmata plasmolysis
  2. Z

    Biology P5

    Now the ball's rolling! Notch it up guys!!
  3. Z

    Chemo P5 tips

    you are absolutely right my friend. I had bungled that paper by drawing two straight lines!!!
  4. Z

    Chemo P5 tips

    ER of Physics M/J 2010 P2 clearly states that: examiners were surprised to find a firmly ingrained belief in candidates that the line of best fit couldn't be a curve. I think the same thing is playing out here.
  5. Z

    Chemo P5 tips

    I got 14.00 g
  6. Z

    Biology P5

    http://www.thestudentroom.co.uk/wiki/Re ... xperiments
  7. Z

    Biology P5

    Measuring transpiration rate using potometer: http://en.wikipedia.org/wiki/Potometer - Must cut the shoots under water at an angle. If air gets into the xylem vessel of the plant, it can form air locks that will prevent the plant taking up water and so reduce the measured rate of...
  8. Z

    Biology P5

    Tit bits about photosynthesis experiments: 1. To measure light intensity, use light meter/ photo diode/LDR/photometer 2. Hydrogen carbonate is an irritant. So, use gloves and eye protection 3. Do not look directly into lamps 4. Do not touch the lamps while hot 150 W halogen lamps the best. They...
  9. Z

    Biology P5

    How to make alignate beads of algae: (I) First why should we go through the trouble at all? 1. Algal balls make it easy to standardise the amount of photosynthetic tissue in any investigation, enabling semi-quantitative experiments to be undertaken. 2. The algae in the beads will stay alive...
  10. Z

    Biology P5

    How to determine the RATE of oxygen uptake Close the screw clip Allow to stabilise Note position of manometer fluid and start the clock Note the position of the syringe at the point of starting Read position of the fluid at fixed times and after each fixed time equalize the levels with the help...
  11. Z

    Biology P5

    I am thinking of doing that too but statistics is a total nightmare!!!!!!!!!!!
  12. Z

    Biology P5

    How to measure RQ: Force your self to go through this piece of nightmare: http://www.practicalbiology.org/areas/a ... 8,EXP.html
  13. Z

    pre-2002 papers

    Same here man, same here
  14. Z

    Biology P5

    Counting stomatal density: Two ways: 1. Using epidermal strips: Epidermal strips: The epidermis will peel from some leaves quite readily - First cut the leaf. We can use our fingernails to catch hold of the leaf and peel off the epidermis, or we can use a sharp RAZOR BLADE (this sucker keeps...
  15. Z

    Biology P5

    Investigation into where chloroplasts are found iin a leaf of a flowering plant: (I) Preparing a microscopic slide of a sample of the leaf - Let us use the leaf of a maize plant. - Cut thin SECTION of the the leaf using a RAZOR/SCALPEL - The mark scheme mentions something about "point of...
  16. Z

    Biology P5

    Practical details of how to prepare a slide of pollen grains and examine them using a microscope: 1. Brush the pollen grain using a brush and transfer it from the stamen to the slide 2. Use a suitable MOUNTANT such as water or glycerol. Iodine solution or methylene blue can also be used to stain...
  17. Z

    Biology P5

    How to use a colorimeter: Determine the wavelength of light that the solution absorbs most strongly. This is simply the complimentary colour of visible colour of the solution Use a color filter that filters out all but the complimentary color and set the wavelength of the colorimeter to the...
  18. Z

    Biology P5

    Hydrogen peroxide less that 18 vol are low hazard. Solution at concentration 18-28 vol are irritant and any higher concentration is corrosive At all times avoid contact of enzymes with EYES or SKIN. If you happen to come in contact, wash off immediately with plenty of water
  19. Z

    Biology P5

    10 vol H202 : It will produce 10cm3 of oxygen from every cm3 that decomposes. Likewise, 2cm3 10vol H2O2 will give 20cm3 of oxygen Mass-volume %= Mass of solid solute in g per 100 ml of the resulting solution. Often used for solutions made from a solid solute dissolved in a liquid...
  20. Z

    Biology P5

    For food tests: There is only one important point that I would like to make: If the sample is a piece of food, then grind it WITH SOME WATER in a PESTLE and MORTAR to break up cells and release the cell contents. These tests are SEMI-QUANTITATIVE as exact concentrations of chemicals cannot be...
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