Biology

• Cell division


  The process by which cells in living things reproduce, resulting in growth and repair of tissues
• Mitosis


  Division of body cells
• Cells


  Small structures that make up living things
• Things cells need


  • Food
  • Oxygen for growth and to repair tissues for respiration
  • Suitable temperature to remove wastes
  • Water for chemical reactions to transport substances and prevent dehydration
• Nucleus


  • Controls activities and chemical reactions in cell
• Cell Membrane


  • Allows substances to move in and out of the cell
• Cytoplasm


  • Stores substances; allows chemical reactions
• Cell Wall


  • Keeps plant cells strong and rigid
• Chloroplast


  • Contains Green pigment needed for photosynthesis
• Vacuole


  • Stores chemicals and water
• Circulatory System


  Consists of the heart, blood and blood vessels
• Blood circulation


  1. Blood is transported through blood vessels pumped by the heart

  2. Blood collects food from the intestines and oxygen from lungs

  3. It carries the food and oxygen in blood vessels to cells used for growth repair of tissues and for respiration

  4. Water formed in cells is collected by blood and taken to lungs and kidneys where they are removed from the body
• Digestion


  Food can be broken down mechanical or chemical
• Mechanical digestion


  • Teeth grinding down food
  • Bile breaking fats into small lumps
• Chemical digestion


  1. Occurs in the mouth, stomach and saliva

  2. Saliva contains an enzyme which begins the chemical breakdown of starch

  3. Stomach walls produce acid and break down protein

  4. Bile from the liver enters the small intestine and breaks up fats so enzymes from pancreas can complete the chemical digestion of proteins, carbohydrates and fats