Microscopy Practical and Measurements

This page focuses on the practical aspects of microscopy, particularly the GCSE cheek cell microscope practical, and provides important information about units of measurement used in cell biology.

The document outlines the equipment needed for the cheek cell practical:

• Sterile swab
• Slide
• Coverslip
• Microscope
• Disinfectant
• Methylene blue (stain)

It then provides a step-by-step method for observing cheek cells under a microscope:

1. Use a sterile swab to collect cells from the inside of your cheek.
2. Rub the swab onto the center of a microscope slide.
3. Add a drop of methylene blue stain to the cells.
4. Gently place a coverslip on top of the stained cells.
5. Put the slide under the microscope, starting with the lowest magnification.
6. Adjust the microscope to focus the image.

Highlight: It's important to clean up any leaked stain with a paper towel and to disinfect all equipment after use.

This practical guide is essential for students preparing for their human cheek cell experiment and understanding what a cheek cell under microscope labeled should look like.

The page also covers units of measurement used in cell biology:

Vocabulary: Most measurements in cell biology are given in micrometers (μm).

It provides conversion factors between different units:

• 1 m = 1000 mm
• 1 mm = 1000 μm
• 1 μm = 1000 nm

Example: To convert 1 mm to μm, multiply by 1000. So, 1 mm = 1000 μm.

This information is crucial for students working on problems involving cell size and microscope magnification, such as calculating the actual size of a cheek cell under microscope 400x or 10x.

The document emphasizes the importance of converting all measurements to the same unit before performing any calculations on magnification or size. This is a key skill for GCSE biology students when interpreting microscope images and understanding the scale of cellular structures.

Cell Organelles and Microscopy

This page provides a comprehensive overview of cell structures and microscopy techniques essential for GCSE cells and organelle functions. It includes detailed diagrams of both animal and plant cells, highlighting key organelles and their functions.

The animal cell diagram showcases important structures such as the nucleus, mitochondria, cytoplasm, and cell membrane. The plant cell diagram includes additional structures like the cell wall, vacuole, and chloroplasts.

Definition: The function of cell membrane is to control what goes in and out of the cell.

Highlight: The function of cell wall in plant cells is to provide structure and is made of cellulose.

The page also features a detailed diagram of a light microscope, labeling its key components such as the eyepiece, objective lenses, stage, and condenser. This is crucial for understanding light and electron microscopy GCSE questions.

Vocabulary: Magnification is defined as how much bigger the image of a sample is relative to its actual size.

The document explains that the total magnification of a microscope is calculated by multiplying the magnification of the eyepiece lens by the magnification of the objective lens.

Example: If the eyepiece lens has a magnification of 10x and the objective lens has a magnification of 40x, the total magnification would be 400x.

Lastly, the page compares light and electron microscopes:

Highlight: Electron microscopes have a higher magnification and a higher resolution, while light microscopes have a lower magnification and lower resolution.

This information is crucial for understanding the 5 differences between light and electron microscope and the disadvantages of electron microscope GCSE studies often cover.