Question 1: Define transpiration in plants.

Answer: Transpiration is the process by which water vapour is lost from plants, primarily through small openings called stomata on the leaves.

Question 2: Explain how environmental factors such as wind and temperature influence transpiration rates.

Answer: Increased wind and higher temperatures can increase transpiration rates by removing the water vapour around the stomata, encouraging more water to evaporate from the leaf surfaces.

Question 3: Describe the mechanism by which water moves from the roots to the leaves during transpiration.

Answer: Water moves from the roots to the leaves through the xylem vessels by capillarity and transpiration pull, driven by water evaporation from the stomata.

Question 1: A football player loses 0.5 litres of water through sweating during a match lasting 2 hours. If the player's sweat rate is constant, what is the rate of water loss per hour in millilitres?

Answer: 250 ml per hour

Question 2: Calculate the amount of water a plant loses in 24 hours if its transpiration rate is 300 millilitres per hour.

Answer: 7200 millilitres (or 7.2 litres)

Question 1: Outline a simple experiment to measure the effect of humidity on the rate of transpiration in a plant.

Answer: Set up two identical potted plants with the same species and size. Cover one with a plastic bag to increase humidity around its leaves, leaving the other exposed. Measure the water loss over a specified time by weighing the pots before and after. Compare the water loss to determine the effect of humidity on transpiration.

Question 2: Identify two variables that should be controlled in experiments studying transpiration.

Answer: Variables such as temperature and light intensity should be controlled to ensure accurate results.

Question 3: Name a safety precaution to consider when conducting transpiration experiments involving chemicals or heat.

Answer: Ensure proper handling and disposal of chemicals, and use heat sources carefully to prevent burns or fires.

Question 1: A study recorded the transpiration rates of a plant under three conditions: low wind (100 ml/hr), moderate wind (200 ml/hr), and high wind (400 ml/hr). Describe what these results suggest about the effect of wind on transpiration.

Answer: The results suggest that increased wind speeds significantly increase the rate of transpiration, likely due to the removal of humid air around the stomata, encouraging more water to evaporate.

Question 2: In a humid environment, a plant's transpiration rate drops to 50 ml/hr. Explain the biological reason for this decrease.

Answer: High humidity reduces the water vapour gradient between the inside of the leaf and the surrounding air, decreasing the rate of water evaporation from the stomata.

Question 1: Discuss how the principles of transpiration are relevant to understanding hydration strategies for athletes, especially in hot and windy conditions. Include in your answer how plants and humans share similar water regulation mechanisms.

Answer: Both plants and humans regulate water loss through mechanisms influenced by environmental factors. In hot and windy conditions, plants increase transpiration to cool leaves and prevent overheating, while humans sweat to maintain body temperature. Understanding transpiration helps in developing hydration strategies for athletes, such as drinking water before, during, and after exercise, especially in conditions that promote rapid water loss. Both systems rely on controlling water vapour exchange with the environment to maintain internal stability, highlighting the importance of water management in biological systems.

Question 1: A sports clothing company develops moisture-wicking fabrics inspired by plant transpiration. Explain how understanding transpiration enhances the development of such fabrics and the benefits it provides to athletes.

Answer: Understanding transpiration allows designers to create fabrics that mimic how plants manage water loss, enhancing moisture evaporation from the skin. This helps keep athletes dry and cool, improving comfort and performance during exercise.

Question 2: Describe how knowledge of plant transpiration can inform agricultural practices to optimise crop hydration in hot climates.

Answer: By understanding transpiration, farmers can implement strategies like shading or controlled irrigation to reduce water loss and ensure crops remain hydrated, especially in hot climates, improving yield and sustainability.