3.1

• What is the main purpose of a microscope?

  To enlarge images of small objects for study
• Who are credited with the invention of the microscope?

  Hans and Zacharias Janssen
• What year is associated with the invention of the microscope?

  Around the year 1590
• Who is considered the first person to observe microbes?

  Antoine van Leeuwenhoek
• What term did Antoine van Leeuwenhoek use to describe microbes?

  Animalcules
• What significant contribution did Robert Hooke make to microscopy?

  He published the book entitled Micrographia in 1665
• What did Robert Hooke first describe as "honey-comb" and "small bladders of air"?

  Structures that we now know as cells
• What is a compound light microscope?

  An instrument containing two lenses that magnifies and has knobs to focus the picture
• What does magnification refer to in microscopy?

  The ability to make smaller objects look larger compared to their original sizes
• What does resolution describe in microscopy?

  The capability of a system to distinguish details in a sample being viewed
• How is contrast defined in microscopy?

  As the relative difference in light intensity between the image and the background
• What are light microscopes classified as?

  Microscopes that use light to visualize images
• What are the two types of light microscopes mentioned?

  Brightfield and darkfield microscopes
• How does a brightfield microscope create an image?

  By directing light from a light source to the specimen being observed
• What type of image does a brightfield microscope produce?

  A dark image in a light background
• What is the function of the small opaque light stop in a dark field microscope?

  To block most of the light coming from the light source
• What are the two basic types of electron microscopes?

  Transmission electron microscope and scanning electron microscope
• What is the primary use of transmission electron microscopes (TEM)?


  For studying the inner morphology of samples
• What is required for samples to be viewed under a transmission electron microscope?

  Ultra-thin slices of samples stained with metals like gold or palladium
• What is the primary use of scanning electron microscopes (SEM)?

  To study the surfaces of samples
• What are the key differences between transmission electron microscopes (TEM) and scanning electron microscopes (SEM)?

  • TEM is used for studying inner morphology, requires ultra-thin slices, and stained samples.
  • SEM is used for studying surfaces and does not require thin sections.