B1

• Animal Cell


  A cell made up of; nucleus, cytoplasm, cell membrane, mitochondria, ribosomes
• Plant cell


  a cell made up of; nucleus, cytoplasm, cell membrane, mitochondria, ribosomes, cell wall, permanent vacuole, chloroplasts
• Bacterial cell


  a cell made up of; cytoplasm, cell membrane, cell wall, plasmids, chromosomal DNA

  Don't have a nucleus

  Contain on or more small rings of DNA called plasmids

  No chloroplasts or mitochondria
• Nucleus


  It contains the genetic material that controls the activities of the cell
• Cytoplasm


  a gel-like substance where most of the chemical reactions take place. It contains enzymes which control these reactions
• Cell membrane


  it holds the cell together and controls what goes in and out of the cell
• Mitochondria


  they are the site of aerobic respiration (respiration transfers energy that the cell needs to work)
• Cell wall


  it supports the cell and strengthens it
• Vacuole


  it contains cell sap (a weak solution of sugar and salts)
• Chloroplasts


  these are where photosynthesis occurs and they contain a green substance called chlorophyll which absorbs the light needed for photosynthesis15 / 88
• Plasmids


  extra rings of DNA in bacterial cells
• Chromosomal DNA


  a single strand of DNA floating freely in the cytoplasm of a bacterial cell
• Ribosomes 


  These are where proteins are made in the cell
• Eukaryotes


  More complex and include all animal and plant cells
• Prokaryotes


  No nucleus
• Chloroplasts


  Where photosynthesis occurs, which makes food for the plant. They contain a green substance called chlorophyll, which absorbs the light needed for photosynthesis.
• Magnification


  Magnification = image /actual
• Microscopes

  • Microscopes allow us to see things we can't see with the naked eye
• Electron Microscopes

  • Use electrons instead of light to form an image
  • Higher magnification and resolution than light microscopes.
  • Let us to see smaller things in more detail
  • Very expensive and not portable
• Light microscopes


  Uses light and lenses to form an image of a specimen and magnify it

  Let us see individual cells and larger subcellular structures, like nuclei.

  Cheaper than electron microscopes and portable.
• Differentiation


  The process by which a cell changes to become specialised for its job
• Sperm Cells

  Specialised for reproduction

  • Long tail and streamlined head to help it swim to the egg
  • There are lots of mitochondria in the cell to provide the energy needed
• Nerve Cells

  • Function is to carry electrical signals form one part of the body to another
  • Long to cover more distance
  • Branched connections at their ends to connect to other nerve cells and form a network throughout the body
• Muscle Cells


  The function of a muscle cell is to contract quickly

  • Cells are long so they have space to contract
  • Contain lots of mitochondria to generate energy needed for contraction
• Root hair cells


  Root hair cells are on the surface of plant roots

  Gives the plant a large surface area for absorbing water and mineral ions