Biology 9700 Practical Notes //top\\

Examiners frequently ask you to prepare specific concentrations using serial or proportional dilutions.

from tube 1 to tube 2 and mix thoroughly. (Tube 2 is now 5%). Transfer 10 cm3cm cubed from tube 2 to tube 3 and mix. (Tube 3 is now 2.5%). Repeat the process across the remaining tubes. 6. High-Scoring Data Presentation Drawing Rules for Biological Diagrams

Maximize your efficiency in the laboratory by organizing your workflow around these proven strategies:

: Control distance from a light source or use specific lamp wattages. 2. Biological Drawings & Data Presentation biology 9700 practical notes

(Image size / Actual size). Always use the same units (usually 3. Data Presentation & Evaluation

Measure the volume of oxygen released using a gas syringe or by counting bubbles per minute.

Doing this immediately gets you into the highest mark band. Transfer 10 cm3cm cubed from tube 2 to tube 3 and mix

Count the number of eyepiece graticule units (EGU) and stage micrometer divisions (SMD) between these points. Calculate the value of 1 EGU:

Comprehensive Guide to Biology 9700 Practical Notes (AS & A Level)

Measure fluids using accurate graduated pipettes or digital micropipettes. Quantifying Apparatus Uncertainty neutralize with NaHCO3NaHCO sub 3

Use Pearson's for normally distributed, linear quantitative data.

: Lines must be sharp, continuous, and drawn with a sharp pencil (no shading).

You must memorize the reagents, procedures, positive results, and negative results for the standard biochemical tests. Reagent / Test Hot Water Bath Needed? Positive Result Negative Result Benedict's Solution for 5 mins) Green, Yellow, Orange, or Brick-Red ppt Clear Blue Non-Reducing Sugars Acid Hydrolysis + Benedict's Yes (Boil with , neutralize with NaHCO3NaHCO sub 3 , then heat with Benedict's) Brick-Red precipitate Clear Blue Starch Iodine in KI Solution Blue-Black Yellow-Brown Proteins Biuret Reagent Purple / Violet Lipids Ethanol Emulsion Test No (Mix with ethanol, pour into water) Cloudy White Emulsion Clear / No layer 3. Enzyme Kinetics Experiments