Definitions

• Active transport

  The movement of substances from a more dilute solution to a more concentrated solution (against a concentration gradient) with the use of energy from respiration.
• Adult stem cell

  A type of stem cell that can form many types of cells.
• Agar jelly

  A substance placed in petri dishes which is used to culture microorganisms on.
• Cell differentiation


  The process where a cell becomes specialised to its function.
• Cell membrane

  A partially permeable barrier that surrounds the cell.
• Cell wall

  An outer layer made of cellulose that strengthens plant cells.
• Chloroplast

  An organelle which is the site of photosynthesis.
• Chromosomes

  DNA structures that are found in the nucleus which are made up of genes.
• Diffusion


  Net movement of particles from an area of higher concentration to an area of lower concentration down a concentration gradient. (passive process)
• Embryonic stem cell


  A type of stem cell that can differentiate into most types of human cells
• Eukaryotic cell

  A type of cell found in plants and animals that contains a nucleus.
• Magnification


  How much bigger an image appears compared to the original object.
• Meristematic cells


  A type of stem cell that can differentiate into any type of plant cell.
• Mitochondria


  An organelle which is the site of respiration
• Mitosis


  A type of cell division which produces two genetically identical daughter cells from one parent cell.
• Nucleus


  An organelle found in most eukaryotic cells that contains the genetic material of the cell and controls the activities of the cell.
• Organelle

  A specialised structure found inside a cell.
• Osmosis


  The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.
• Plasmid


  Loops of DNA found in the cytoplasm of prokaryotic cells.
• Prokaryotic cell


  A type of cell found in bacteria that does not contain a nucleus.
• Specialised cells


  Cells that are adapted to perform a specific function.
• Stem cell


  An undifferentiated cell that can divide to produce many specialised cells of the same type.
• The cell cycle


  A series of stages preparing the cell for division.

   
• Therapeutic cloning


  Producing an embryo that has the same genes as a patient.
• Vacuole

  An organelle that stores cell sap.