B1 - B4

• Cell membrane


  Controls the entry and exit of substances into the cell
• Cytoplasm


  Where chemical reactions happen inside the cell
• Ribosomes


  Do protein synthesis which means to make proteins
• Nucleus


  Controls the cell activities
• Mitochondria


  Where aerobic respiration happens and that provides energy for the cell
• Chloroplasts


  Absorb light energy for photosynthesis
• Vacuole


  Contains cell sap and its function is to be able to support the cell structure
• Cell wall


  Strong because it is made of cellulose and that is also there to help the cell structure
• Both animal and plant cells are classed as eukariotic cells
• Eukariotic


  Any cell that has a nucleus and that inside the nucleus is where the DNA is kept
• Procaryotic


  Cells that do not have a nucleus, their DNA is just found in the cytoplasm floating around not inside a nucleus
• Procaryotic cells


  • Bacterial cells
• Plasmids


  Small extra Loops of DNA that often contain useful genes like antibiotic resistance
• Bacterial cell wall


  For structure but also for protection
• The main two differences between procaryotic and eukaryotic cells are that there are no mitochondria or chloroplasts in procaryotic cells and there is no nucleus
• One similarity with plant cells is that there is a cell wall in procaryotic cells however the cell wall in prootic cells is not made of cellulose
• Root hair cells


  • Elongated shape to help absorb water and mineral ions from the soil
• Xylem and phloem


  • Highly specialized to transport substances around the plant
• Sperm cell


  • Flagellum to help it swim to the egg
• Nerve cell


  • Long axon to help transmit electrical impulses across long distances
• Muscle cells


  • Lots of mitochondria to provide the energy to contract
• Cell differentiation


  Cells become specialized through the process of differentiation where different genes are turned on or off in each cell to change their shape or the number of subcellular structures that they have
• Stem cells


  Undifferentiated cells that have not yet differentiated to become specialized
• Plant cells mostly have the ability to differentiate throughout their whole life which is what makes cloning plants possible
• Animal cells do not have this ability and most animal cells differentiate in an early stage and once they're specialized very few of them can change or become stem cells again
• Optical or light microscopes magnify images so that we can see structures on living material such as cells that are bigger than they actually are
• Magnification


  Calculated by dividing the image size by the actual size of the object
• Electron microscopes have much higher magnification and resolution ability than light microscopes, allowing us to see more detail inside cells and even inside subcellular structures
• Preparing a microscope slide


  1. Add a drop of water

  2. Take a thin piece of tissue

  3. Stain with iodine

  4. Lower a cover slip gently
• Using a microscope


  1. Put slide on stage

  2. Start with lowest power objective lens

  3. Use coarse focus wheel at low power

  4. Increase magnification and use fine focus wheel
• Chromosomes


  Solid structures that DNA coils up into to fit inside the nucleus
• Cell cycle


  The process that all cells go through to prepare for cell division and then divide
• Mitosis


  1. Chromosomes are pulled apart to opposite poles

  2. Cell membrane and cytoplasm divides

  3. Forms two genetically identical daughter cells
• Stem cells


  Undifferentiated cells that can produce different cell types through differentiation
• Types of stem cells


  • Embryonic stem cells
  • Adult stem cells
  • Plant stem cells
• Stem cell therapy can be used to produce cells to replace damaged cells in the body
• There are some ethical issues around using embryonic stem cells as the embryo cannot consent
• Diffusion


  The net movement of particles from an area of high concentration to an area of low concentration
• Treat paralysis


  Grow nerve cells or nerve tissue when that's been damaged in the spine
• Treat type 1 diabetes

  Grow pancreatic cells