Microscopy Flashcards
Draw the equation triangle for calculating magnification
An image of an animal cell is 30mm and it has been magnified by a factor of x3000. What is the actual size of the cell?
When was the first light microscope invented? Briefly describe how a light microscope works.
17th century: Development of the first light microscopes.
Light microscopes use light and lenses to magnify specimens, allowing visualisation of cells and large subcellular structures like nuclei and vacuoles, often with the aid of stains
Their design has evolved to improve magnification and resolution over time
When was the first electron microscope invented? Briefly describe how a light microscope works.
20th century: Introduction of the first electron microscopes.
Electron microscopes use electron beams instead of light, providing much higher resolution and magnification due to the smaller wavelength of electron beams
What are the 3 main advantages of electron microscopes over light microscopes?
- An electron microscope has much higher magnification and resolving power than a light microscope
- They can therefore be used to study cells in much finer detail, enabling biologists to see and understand many more subcellular structures such as the mitochondrion
- They have also helped biologists develop a better understanding of the structure of the nucleus and cell membrane
Describe how you would use a light microscope to observe a specimen (6 marks)
