biology: working as a biologist

  1. Plant cell
    Image Upload 1
  2. Animal cell
    Image Upload 2
  3. Magnification equations
    • mag= size of diagram
    •           -------------------
    •           real size

    • mag= size of image
    •           -----------------
    •           size of object

    mag= eye piece X objective
  4. Electron microscopes
    • - Scanning: 3D image
    • - Transmisson: internail detail
    • (SEM + TEM)

    - When magnification increases the field of view goes down.
  5. Optical microscopes
    • - Compund: two seperate lens stystems, one for each eye. Shows small body in 3D (e.g. ant)
    • - Compound: two or more seperate lenses. Shows interal structure of cells.
  6. Surface area to volume ratio
    SA:V - number of units of surface area. E.g. as the organism gets bigger the ratio or surface area to volume gets smaller.
  7. Exchange of materials across membranes
    • Osmosis: movement of water across a semi permeable membrane from a high concentration to a low concentration.
    • E.G. cell membrane will allow water but not salt.

    Diffusion: molecules of solute spread from areas of low concentration in the solvent.

    • Solvent: substance that dissolves the solute into it.
    • Solute: substance that is dissolved into the solvent.
    • E.G. water (solvent) will have salt dissolve into it (solute).

    Hypotonic: less solute (salt) molecules outside the cell, which causes the water to be sucked in that direction. E.G. the cell will gain water and grow larger.

    Hypertonic: more solute (salt) molecules outside the cell, which causes the water to be sucked in that direction. E.G. the cell will shrink and may die.
Author
Madeline
ID
181060
Card Set
biology: working as a biologist
Description
study
Updated