Module 2

• What are the four different types of microscopes mentioned?

  • Light or Optical microscopes
  • Transmission Electron Microscopes (TEM)
  • Scanning Electron Microscopes (SEM)
  • Laser Scanning Confocal Microscopes
• Why do light or optical microscopes have poor resolution?

  Because their resolution is limited by the wavelength of light used to create the image.
• What type of samples can be used with light or optical microscopes?

  Living samples can be used with light or optical microscopes.
• How do transmission electron microscopes create images?

  Electrons pass through the specimen to create an image with high magnification and resolution.
• What is the main difference between scanning electron microscopes and transmission electron microscopes?

  Scanning electron microscopes create 3D images by bouncing electrons off the surface, while transmission electron microscopes create 2D images by passing electrons through the specimen.
• What is the function of laser scanning confocal microscopes?

  They provide high resolution and 3D images using laser light to illuminate the specimen.
• What does the term resolution refer to in microscopy?

  Resolution is the minimum distance between two objects at which they can still be viewed as separate.
• How is resolution determined in light microscopes compared to electron microscopes?

  In light microscopes, resolution is determined by the wavelength of light, while in electron microscopes, it is determined by the wavelength of electrons.
• What does magnification refer to in microscopy?

  Magnification refers to how many times larger the image is compared to the actual object being viewed.
• What are the four types of slide preparation for light microscopy?

  • Dry Mount
  • Wet Mount
  • Squash Slide
  • Smear Slide
• What is a dry mount slide preparation?

  A dry mount involves placing a thin slice or whole specimen on a glass slide with a cover slip on top.
• What is a wet mount slide preparation?

  A wet mount involves adding specimens to water or a stain before lowering a cover slip to prevent air bubbles.
• How is a squash slide prepared?

  A squash slide is a wet mount where the cover slip is pressed down to create a thin layer of cells for better light passage.
• What is a smear slide preparation?

  A smear slide is created by using the edge of another slide to spread the sample across the slide, creating a thin, even coating.
• What is the purpose of an eyepiece graticule in microscopy?

  The eyepiece graticule is a scale used to measure the size of objects viewed through the microscope.
• How do you calibrate the eyepiece graticule?

  You align the eyepiece graticule with a stage micrometer and count how many divisions fit into one division of the stage micrometer.
• What is the formula for calculating magnification?

  Magnification = size of the image / size of the real object.
• How do you convert millimeters to micrometers?

  To convert millimeters to micrometers, you multiply by 1000.
• What is the purpose of staining in microscopy?

  Staining is used to make certain cell components more visible under the microscope.
• What is differential staining?

  Differential staining involves using multiple chemical stains to color different parts of the cell for better visibility.
• What are two common positively charged stains used in microscopy?

  Crystal violet and methylene blue.
• What is the purpose of gram staining?

  Gram staining is used to identify the type of bacteria based on their cell wall structure.
• How do gram-positive bacteria appear after gram staining?

  Gram-positive bacteria appear blue or purple because they retain the crystal violet stain.
• How do gram-negative bacteria appear after gram staining?

  Gram-negative bacteria appear red due to the counter stain, safranin, as they do not retain the crystal violet stain.
• Why is differential staining important in medicine?

  Differential staining helps determine the type of bacteria present, which informs the choice of antibiotics for treatment.
• What are the rules for scientific drawings in microscopy?

  • Use a sharp pencil
  • Include a title
  • State the magnification or include a scale
  • Annotate cell components
  • Use solid lines without shading or coloring
• What is the function of electron microscopes?

  Electron microscopes use a beam of electrons to create high-resolution images of specimens.
• Why can't living samples be used with electron microscopes?

  Living samples cannot be used because the air would absorb the beam of electrons, requiring a vacuum.
• What type of image do transmission electron microscopes produce?

  Transmission electron microscopes produce 2D images by passing electrons through very thin specimens.
• How do scanning electron microscopes create images?

  Scanning electron microscopes create images by beaming electrons onto the surface of the specimen and capturing the scattered electrons.
• What is the function of laser scanning confocal microscopes?

  They create high-resolution 3D images using laser light and fluorescent dyes.
• What are the 13 organelles found in eukaryotic cells?

  1. Nucleus
  2. Flagella
  3. Cilia
  4. Centrioles
  5. Cytoskeleton
  6. Rough Endoplasmic Reticulum
  7. Smooth Endoplasmic Reticulum
  8. Golgi Apparatus
  9. Mitochondria

  10. Ribosomes

  11. Lysosomes

  12. Peroxisomes

  13. Plasma Membrane
• What is the structure of the nucleus?

  The nucleus is a double membrane structure with nuclear pores, nucleoplasm, and contains chromosomes and a nucleolus.
• What is the function of the nucleolus?

  The nucleolus is responsible for RNA and ribosome synthesis.
• What is the function of flagella in eukaryotic cells?

  Flagella are whip-like structures that provide mobility and can act as sensory organelles.
• What are cilia and their functions?

  Cilia are hair-like projections that can be stationary or mobile, helping to sweep substances along or serving sensory functions.
• What are centrioles and their role in the cell?

  Centrioles are made of microtubules and are involved in spindle fiber formation during mitosis and meiosis.
• What is the cytoskeleton and its function?

  The cytoskeleton is a network of fibers that provides mechanical strength, shape, and stability to the cell.
• What are the two types of endoplasmic reticulum and their functions?

  The rough endoplasmic reticulum is involved in protein synthesis, while the smooth endoplasmic reticulum is involved in lipid and carbohydrate synthesis.
• What is the function of the Golgi apparatus?

  The Golgi apparatus modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.