Microscopy

• Why are microscopes important for biology?

  They allow us to see things that cannot be seen with the naked eye.
• What are the two main types of microscopes mentioned in the study material?

  • Light microscopes
  • Electron microscopes
• How do light microscopes form an image of a specimen?

  They use light and lenses to magnify the specimen.
• What can light microscopes allow us to see?

  Individual cells and large subcellular structures, like nuclei.
• What is the primary difference between electron microscopes and light microscopes?

  Electron microscopes use electrons instead of light to form an image.
• What advantage do electron microscopes have over light microscopes?

  They have a much higher magnification and resolution.
• What does resolution refer to in microscopy?

  It is the ability to distinguish between two points.
• What types of structures can electron microscopes help us see in detail?

  Internal structures of mitochondria and chloroplasts, as well as ribosomes and plasmids.
• What is the formula for calculating magnification?

  • Magnification = image size / real size
• What must be done if image size and real size are in different units when calculating magnification?

  You need to convert them to the same units first.
• If a specimen is 50 µm wide and viewed under a magnification of ×100, what is the image size?

  The image size is 5000 µm or 5 mm.
• How do you write numbers in standard form?

  • Change very big or small numbers into a manageable format.
  • Move the decimal point left or right.
  • Represent the movement with a power of 10 (positive for left, negative for right).
• How would you express 0.0025 mm in standard form?

  1. 25 × 10⁻³ mm.
• What is the importance of keeping track of units in calculations?

  If the units are not the same, the calculations will not work.
• Given a cheek cell viewed under a microscope with ×40 magnification and an image width of 2.4 mm, how do you calculate the real width of the cheek cell in µm?

  Real width = image size / magnification = 2.4 mm / 40 = 0.06 mm = 60 µm.