This required practical covers Required Practical 1: Using a Light Microscope within Cell Structure for GCSE Biology. Cell theory, prokaryotic and eukaryotic cells, animal and plant cell organelles, bacterial cells, specialized cells, and microscopy It is section 11 of 17 in this topic. Revise both the method and the reason for each step, because practical questions often test understanding rather than pure recall.
🧪 Required Practical 1: Using a Light Microscope
Equipment Needed:
- Light microscope
- Microscope slides and coverslips
- Prepared specimens (onion cells, cheek cells)
- Iodine solution (stain)
- Dropping pipette
- Filter paper
Method:
- Set up the microscope: Start with lowest magnification objective lens
- Prepare the specimen: Place thin section on slide, add stain if needed
- Add coverslip: Lower slowly to avoid air bubbles
- Focus on low power: Use coarse focus knob first
- Switch to higher magnification: Use fine focus knob only
- Observe and draw: Label the structures you can see
Key Observations:
- Onion cells: Cell wall, nucleus, cytoplasm
- Cheek cells: Cell membrane, nucleus, cytoplasm
- Plant vs Animal: Compare the shapes and structures
Practice questions for Cell Structure
Which part of the cell contains DNA and controls the cell's activities?
Describe the structure and function of chloroplasts.
Quick recall flashcards
What is the function of ribosomes?
Ribosomes are the sites of protein synthesis. They translate mRNA into proteins by linking amino acids together.
What is the function of the nucleus?
The nucleus is the control center of the cell. It contains DNA which controls all cellular activities and heredity.