Practicals

• What is reaction time?

  It is the time it takes to respond.
• What is the purpose of using quadrats in zoology?

  • To study the distribution of organisms
  • To collect data on how common an organism is in different areas
• What is a habitat?

  A habitat is the place where an organism lives.
• How does the distribution of an organism relate to environmental factors?

  The distribution is affected by environmental factors, making organisms more common in some areas than others.
• Why might daisies be more common in open areas than under trees?

  Because there is more sunlight available in the open.
• What are two methods to study the distribution of an organism?

  1. Measure how common an organism is using quadrats.
  2. Study how distribution changes across an area using transects.
• What is a quadrat?

  A quadrat is a square frame enclosing a known area.
• How do you use a quadrat to study organisms?

  Place it on the ground at randomly chosen coordinates and count the organisms.
• How do you calculate the mean number of organisms per quadrat?

  By dividing the total number of organisms by the number of quadrats.
• If Anna counted 154 daisies in 7 quadrats, what is the mean number of daisies per quadrat?

  22 daisies per quadrat.
• What steps are involved in using transects to study organism distribution?

  1. Mark out a line in the area using tape measure.
  2. Collect data along the line by counting organisms.
  3. Optionally, use quadrats placed at intervals along the line.
• What can you investigate using the enzyme lipase on milk?

  The effect of temperature on the rate of decay.
• What happens when lipase breaks down milk?

  It causes a color change in a determined indicator dye.
• What is the effect of caffeine on reaction time?

  Caffeine speeds up reaction time
• What are the steps to measure reaction time using a ruler?

  1. Sit with arm resting on a table
  2. Hold a ruler vertically between thumb and forefinger
  3. Let go of the ruler without warning
  4. Catch the ruler as quickly as possible
  5. Measure the distance caught on the ruler
  6. Repeat and calculate the mean distance
• How is reaction time measured in the ruler test?

  By the number on the ruler where it's caught
• What should be done after the initial reaction time test?

  Have a caffeinated drink and wait ten minutes
• What variables should be controlled for a fair test?

  • Same person catching the ruler
  • Same hand used each time
  • Ruler dropped from the same height
  • No caffeine before the experiment
• What should the person being tested avoid after the experiment?

  Drinking more caffeine for the rest of the day
• How can reaction time be measured using a computer?

  • Simple computer tests can be used
  • Example: clicking the mouse or pressing a key
• What is the purpose of resting the arm on a table during the test?

  To prevent arm movement during the test
• Why is it important to repeat the ruler test several times?

  To calculate the mean distance for accuracy
• What could happen if the person being tested has caffeine before the experiment?

  It may affect their reaction time results
• What is the recommended amount of cola to consume before retesting?

  300 ml of cola
• What is the significance of reading the ruler from the top of the thumb?

  It indicates the height at which it was caught
• If a person catches the ruler at 20 cm, what does this indicate about their reaction time?

  Their reaction time is relatively slow
• How does the method of measuring reaction time with a computer differ from using a ruler?

  Computer tests often involve clicking or pressing