Biology — 9700 Practical Notes

Measuring reaction times, observing the effects of temperature, or using inhibitors.

You must be able to calibrate an eyepiece graticule using a stage micrometer. Remember: Biological Drawing:

Look across the scale to find another point where two lines align perfectly. Step 3: Count the number of stage micrometer divisions ( ) and eyepiece units ( ) between the two aligned points. Step 4: Calculate the distance using the formula above. The Magnification Formula Always remember the standard triangle formula: biology 9700 practical notes

The independent variable goes on the x-axis. Use at least half the provided grid. Points should be joined with ruled straight lines unless a curve is specifically requested. Error Analysis: Distinguish between systematic errors (instrumental) and random errors

Keep your test tubes visible until you finish writing your answers. You may notice a late color change or sedimentation that alters your conclusion. Step 3: Count the number of stage micrometer

Mastering the practical component of the Cambridge International AS & A Level Biology (9700) syllabus is essential for achieving a high grade. The practical papers (Paper 3 for AS and Paper 5 for A2) test your ability to plan, conduct, analyze, and evaluate biological experiments, rather than just recalling theoretical knowledge.

Must include the quantity and the unit separated by a slash (e.g., Temperature / °C Consistency: Use at least half the provided grid

: Diluting a solution step-by-step by the same factor (e.g., 10x each time). 2. Biological Drawings & Microscopy

Add equal volumes of Benedict's reagent and the sample. Heat in a water bath at 80–100°C for 5 minutes. A color change from blue to green, yellow, orange, or brick-red indicates a positive result.

Observe the arrangement of vascular bundles (xylem on the inside, phloem on the outside). 3. Estimating Uncertainty and Evaluating Errors

Add a few drops of Iodine in Potassium Iodide solution to the sample at room temperature. Color Change: Yellow-brown turns to a deep Blue-black. Biuret Test for Proteins