Topic 1 Bio

• Eukaryotic cells


  Animal and plant cells
• Prokaryotic cells


  Bacterial cells
• Structures in eukaryotic cells


  • Cell membrane
  • Cytoplasm
  • Nucleus containing DNA
• Structures in prokaryotic cells


  • Cell wall
  • Cell membrane
  • Cytoplasm
  • Single circular strand of DNA and plasmids
• Organelles


  Structures in a cell that have different functions
• Organelles in animal and plant cells


  • Nucleus
  • Cytoplasm
  • Cell membrane
  • Mitochondria
  • Ribosomes
• Additional organelles only in plant cells


  • Chloroplasts
  • Permanent vacuole
  • Cell wall
• Structures in bacterial cells


  • Cytoplasm
  • Cell membrane
  • Cell wall
  • Chromosomal DNA (circular)
  • Plasmids
  • Flagella
• Differentiation


  A process that involves the cell gaining new sub-cellular structures in order for it to be suited to its role
• Specialised animal cells


  • Sperm cells
  • Egg cells
  • Ciliated epithelial cells
• Specialised plant cells


  • Root hair cells
  • Xylem cells
  • Phloem cells
• Light microscope


  Has two lenses, usually illuminated from underneath, maximum magnification of 2000x, resolving power of 200nm
• Electron microscope


  Uses electrons instead of light, higher magnification (up to 2,000,000x) and resolving power (10nm for SEM, 0.2nm for TEM)
• Electron microscopes have allowed the discovery of viruses and detailed examination of proteins
• Magnification


  Magnification of the eyepiece lens x magnification of the objective lens
• Size of an object

  Size of image/magnification = size of object
• Standard form


  Multiplying a number by a power of 10 to get bigger or smaller numbers, with the 'number' between 1 and 10
• Orders of magnitude


  Understanding how much bigger or smaller one object is compared to another
• Prefixes


  • Centi (0.01)
  • Milli (0.001)
  • Micro (0.000,001)
  • Nano (0.000,000,001)
• Estimating quantities


  Take a sample, count the number in the sample, then multiply by the number of samples in the whole area
• Parts of a light microscope

  • Eyepiece
  • Barrel
  • Turret
  • Lens
  • Stage