cell structure - B1

• What is the function of ribosomes in animal cells?

  Protein synthesis
• What process occurs in mitochondria?

  Aerobic respiration
• What is the role of the cytoplasm in a cell?

  It is the site of chemical reactions
• What does the nucleus contain in a plant cell?

  DNA
• What is the function of the cell wall in plant cells?

  Provides structure
• What is the function of chloroplasts in plant cells?

  Photosynthesis
• What do plasmids contain in bacterial cells?

  Genetic material
• What is the formula for magnification?

  Magnification = Image size / Actual size
• How is magnification calculated using eyepiece and objective lenses?

  Magnification = eyepiece x objective
• What does magnification indicate?

  How many times bigger an image is than the real object
• What is resolution in microscopy?

  The ability to distinguish between separate points
• What type of microscope has greater resolution?

  Electron microscope
• Why is a light microscope limited in resolution?

  It cannot see smaller details clearly
• What is a micrometer?

  One thousandth of a millimeter
• What are the steps to prepare a microscope slide?

  1. Remove a thin layer of onion skin
  2. Place on slide and ensure it's flat
  3. Add iodine to the onion
  4. Cover with a slip using a mounted needle to avoid air bubbles
• What is the purpose of iodine in slide preparation?

  To stain and make organelles visible
• What is the advantage of using the lowest magnification on a microscope?

  It allows for the largest field of vision
• What is cell specialization?

  • When a cell becomes specialized for a specific function
  • Changes can include:
  • Size or shape alterations
  • Changes in organelle number or type
  • Alterations in cell contents
• What is an example of a specialized cell and its adaptation?

  Hair cell has a large surface area for osmosis
• What is passive transport?

  Movement of particles from high to low concentration without energy
• What factors can speed up diffusion?

  Increasing concentration gradient and surface area
• What is the significance of the SA:V ratio in unicellular organisms?

  They have a large SA:V ratio for efficient nutrient absorption
• What happens in hypertonic solutions?

  Causes osmosis out of the cell, leading to cell shrinkage
• What occurs in hypotonic solutions?

  Causes osmosis into cells, potentially leading to cytolysis
• What is cytolysis?

  Bursts of animal cells due to excess water intake
• What is the procedure for the potato practical in osmosis experiments?

  1. Measure equal volumes of salt solutions
  2. Cut potato to the same length
  3. Calculate surface area as a cube: $SA =$$L \times W \times H$
  4. Place in each solution and cover with clingfilm
  5. Leave to dry and weigh again
  6. Calculate % change
• What is active transport?

  Movement of particles across a membrane against a concentration gradient using energy
• Why do muscle cells have many mitochondria?

  For respiration to provide energy