Required practicals

• Homeostasis


  Biological process that regulates the internal environment of an organism to maintain a stable, constant condition
• Required Practical: Human reaction times

  1. Plan and carry out an investigation

  2. Determine the effect of a specific factor on human reaction times
• Suitable investigation


  • Investigate the effect of caffeine or background noise on reaction times
• Ruler Drop Test


  1. Independent variable

  2. Dependent variable

  3. Control variable

  4. Amount of practice

  5. Same person being tested and administering the test
• Method

  1. Work with a partner

  2. Person A holds out hand with thumb and finger gap

  3. Person B holds ruler with zero at top of thumb

  4. Person B drops ruler, Person A must catch it

  5. Record number on ruler

  6. Repeat 10 times

  7. Swap roles and record
• Formula


  t = √0.2xd
• Cells are the basic unit of all forms of life
• Cells are controlled by the nucleus
• For an organism to grow, cells must divide
• Cell division is the process of growth and repair in organisms
• Structural differences in cells enable them to perform specific functions within the organism
• With noise


  Reaction times are slower compared to without noise
• Reaction times are measured in centimetres