Microscope

• What is organelle y?

  Golgi apparatus

  
• What are two other features that show that amoeba is a eukaryotic cell?

  nucleus and mitochondria

  
• What is the function of organelle z?

  Mitochondria - goes through aerobic respiration to provide energy

  
• Why would a scientist use a transmission electron microscope to study the structure of an amoeba?

  It’s got a higher resolution to investigate organelles
• Contrast how an optical microscope and transmission microscope work and how they contrast in limitations of their use when studying cells.

  TEM uses electrons and optical uses light

  TEM has a greater resolution so organelles can be observed

  TEM can only observe dead species but optical can view live specimens

  TEM doesn’t show colour but optical does

  TEM requires thin specimens
• Describe the principles and limitations of using a transmission electron microscope.

  Principles

  • electrons pass through thin specimens
  • Electrons have a short wavelength meaning a higher resolution to see organelles
  • Limitations
  • Only 2D image
  • Specimen must be very thin
  • Cannot be living specie as it goes in a vacuum
  • Artefacts are present
• This is a cholera bacterium that has been magnified 50000 times.

  Name A.

  Cell membrane

  
• Name 2 structures in a epithelial cell from the small inestine that are not in a cholera bacterium.

  nucleus, mitochondria

  
• Cholera bacteria can be viewed using a TEM microscope or an SEM microscope.

  Why is a TEM better ?

  Higher resolution

  Allows ability to see internal details
• give an advantage of using SEM over TEM

  You can have 3D images
• Describe the relationship between number of deaths from cholera and height at which people lived above sea level

  As the height increases the number of deaths decrease