Electron microscopy, and the size and scale of cells
Lesson details
Learning outcome
You can describe the size and scale of cells and cell structures, and explain how electron microscopy has increased our understanding of sub-cellular structures.
Key learning points
- Most cells are too small to be seen without a microscope.
- Comparison of the sizes of cells and cell structures.
- Light microscopes have limited magnification and resolution.
- Electron microscopes have greater magnification and resolution, allowing much smaller structures to be seen clearly.
- Electron microscopy has increased our understanding of sub-cellular structures.
Keywords
Light microscope - a type of microscope that uses visible light and a system of lenses to generate magnified images of small objects
Magnification - making small objects appear larger in order to see more detail
Resolution - the minimum distance at which two distinct points of a specimen can still be seen
Electron microscope - a type of microscope that uses a beam of electrons instead of light. Electron microscopes have a higher magnification and resolving power than light microscopes
Common misconception
Pupils may think that all cells are approximately the same size.
Calculations in the deck will allow pupils to compare the relative sizes of cells. It might be helpful to draw extra attention to this point.
Teacher tip
It might be helpful to print out a large version of the unit conversion table to put up in the classroom so that pupils become more familiar with the unit prefixes.
Equipment
calculators
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What is the term for the most basic units of living organisms?
Q2.In which type of cell is genetic material typically not enclosed within a membrane-bound nucleus?
Q3.Which of the following is present in both prokaryotic and eukaryotic cells?
Q4.What is the main purpose of a microscope?
Q5.Which of the following are eukaryotes?
Q6.What is an electron?
Assessment exit quiz
6 Questions
Q1.Which type of microscope uses electrons to view specimens in 3D?
Q2.In microscopy, what does the term 'resolution' refer to?
Q3.Which microscope would be most suitable for observing detailed structures within a cell, such as chloroplasts?
Q4.A typical human hair has a diameter of approximately 60 micrometres (µm). What is its diameter in nanometres?
Q5.The nucleus of a cell measures 5 micrometres (µm) in diameter. In an image, the nucleus appears as 20 millimetres. What is the magnification of the nucleus in the image?
Q6.A plant cell has a length of 20 µm, while a bacterium measures 2 µm in length. How many times longer is the plant cell compared to the bacterium?
To help you plan your 11 biology lesson on: Electron microscopy, and the size and scale of cells, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 11 biology lesson on: Electron microscopy, and the size and scale of cells, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 biology lessons from the Classification in modern biology unit, dive into the full secondary biology curriculum, or learn more about lesson planning.