Investigating Transpiration

• What is a potometer used for?

  A potometer is used to estimate the transpiration rate of a plant cutting.
• How can you estimate the transpiration rate using a potometer?

  By measuring the distance the bubble moves in a given time.
• If a bubble moved 25 mm in 10 minutes, what is the transpiration rate?

  The transpiration rate is $25 \text{ mm} / 10 \text{ min} =$$2.5 \text{ mm/min}$.
• How else can you estimate transpiration rate besides measuring bubble movement?

  By calculating the percentage change in mass of the potometer.
• What is the formula to calculate the percentage change in mass?

  Percentage change = (change in mass / initial mass) * 100.
• What environmental conditions can affect transpiration rates?

  Light intensity, temperature, and air movement.
• How can you increase light intensity to affect transpiration rate?

  By placing the potometer in a brighter location.
• What effect does increasing temperature have on transpiration rate?

  Increasing temperature should increase the transpiration rate.
• How can you create air movement around the plant to affect transpiration rate?

  By using a fan to increase air circulation.
• What should you keep constant when investigating the effect of temperature on transpiration rate?

  All other environmental variables except temperature.
• What is the primary function of a potometer in plant experiments?

  To measure the rate of transpiration in plants.
• Why is it important to control variables in an experiment investigating transpiration?

  To ensure that the results are due to the factor being tested.