Biology module 2

• What are the four different types of microscopes mentioned?


  Light microscopes, transmission electron microscopes, scanning electron microscopes, and laser scanning confocal microscopes
• Why do light or optical microscopes have poor resolution?


  Because of the wavelength of light used to create the image
• What type of samples can be used with light microscopes?


  Living samples
• How do transmission electron microscopes create images?


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


  Scanning electron microscopes create 3D images while transmission electron microscopes create 2D images
• What do laser scanning confocal microscopes use to create images?


  Laser light
• What is resolution in microscopy?


  The minimum distance between two objects in which they can still be viewed as separate
• How is resolution determined in light microscopes?


  By the wavelength of the light
• How is resolution determined in electron microscopes?


  By the wavelength of an electron
• What does magnification refer to in microscopy?


  How many times larger the image is compared to the actual object
• What are the four types of slide preparation for light microscopy?


  Dry mount, wet mount, squash slide, and smear slide
• What is a dry mount slide preparation?


  Thin slices or whole specimens are placed on a glass slide with a cover slip
• What is a wet mount slide preparation?


  Specimens are added to water or a stain before placing a cover slip
• What is a squash slide preparation?


  A wet mount where the cover slip is pressed down to create a thin layer of cells
• What is a smear slide preparation?


  A drop of sample is smeared across the slide and covered with a cover slip
• What is the purpose of the eyepiece graticule in a light microscope?


  To measure the size of the object being viewed
• How do you calibrate the eyepiece graticule?


  By using a stage micrometer to align and measure divisions
• What is the formula for calculating magnification?


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


  By multiplying by 1,000
• What is differential staining?


  A technique that uses different chemical stains to color different parts of cells
• What are two common stains used in differential staining?

  Crystal violet and methylene blue
• What is the purpose of scientific drawings in microscopy?


  To record observations of structures under a microscope
• What are the rules for creating a scientific drawing?


  Use a pencil, include a title, state magnification, label key features, and avoid shading
• What is the function of the cytoskeleton?


  To provide mechanical strength and maintain the shape of the cell
• What are the two types of endoplasmic reticulum?


  Rough and smooth endoplasmic reticulum
• What is the function of rough endoplasmic reticulum?


  Protein synthesis for proteins destined to leave the cell
• What is the function of smooth endoplasmic reticulum?


  Synthesis and storage of lipids and carbohydrates
• What is the function of the Golgi apparatus?


  Modification, sorting, and packaging of proteins and lipids
• What are lysosomes?


  Vesicles containing digestive enzymes for breaking down waste
• What is the function of mitochondria?


  Site of aerobic respiration and ATP production
• What are ribosomes made of?


  Two subunits of protein and RNA
• What type of ribosomes are found in eukaryotic cells?


  80S ribosomes
• What type of ribosomes are found in prokaryotic cells?


  70S ribosomes
• What is the significance of the double membrane in mitochondria?


  It allows compartmentalization of processes for aerobic respiration
• What is the role of the nucleolus?


  Site of RNA production and ribosome synthesis
• What are chromosomes made of?


  Protein-bound DNA wrapped around histone proteins
• What is the function of cilia?


  To move substances along the surface of cells or act as sensory organelles
• What is the function of flagella?


  To provide mobility to certain cells
• What is the role of centrioles?


  Involved in spindle fiber formation during cell division
• What are microtubules?


  Components of the cytoskeleton that help maintain cell shape and structure