Key Terms for Practical Investigations
Part of Cell Biology Practical Investigations — GCSE Biology
This definitions covers Key Terms for Practical Investigations within Cell Biology Practical Investigations for GCSE Biology. Comprehensive practical skills, experimental design, data analysis, microscopy techniques, and scientific methodology in cell biology It is section 10 of 17 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 10 of 17
Practice
20 questions
Recall
20 flashcards
Key Terms for Practical Investigations
- Magnification
- How many times larger an image appears compared to the actual object. Calculated as: Image size divided by Real size.
- Resolution
- The ability to distinguish between two points that are close together. A high-resolution image shows fine detail clearly; a low-resolution image appears blurry even when magnified.
- Staining
- Adding a coloured dye to a prepared slide to make cell structures visible. Most cell structures are colourless and transparent without staining.
- Iodine solution
- A stain that turns starch (and some cell walls) dark blue-black. Commonly used to stain plant cells and make the cell wall visible.
- Methylene blue
- A stain that colours nuclei and other acidic cell components blue. Commonly used to stain animal cells (e.g., cheek cells) to make the nucleus visible.
- Eyepiece graticule
- A scale built into the eyepiece of the microscope. Used to measure the size of cells. Must be calibrated against a stage micrometer before use.
- Stage micrometer
- A microscope slide with a precise scale engraved on it, used to calibrate the eyepiece graticule.
- Real size (actual size)
- The true size of the object being observed. Calculated as: Image size divided by Magnification.
- Image size
- The size of the object as it appears under the microscope (or in a photograph). Calculated as: Magnification multiplied by Real size.
Must Memorise: Magnification formula — Magnification = Image size / Real size (rearrange as needed using the MIR triangle). Resolution is about CLARITY not size — a high-magnification blurry image has low resolution.