The correct answer is C. Unaffected by humidity. Detailed Explanation: Transpiration is the process by which water vapor is lost from the aerial parts of plants, primarily through small openings called stomata. The rate of transpiration can be influenced by several environmental factors, including temperature, light intensity, humidity, and air movement. Let's break down each option to understand why option C is the incorrect statement. A. Dependent on temperature

• Explanation: Temperature plays a significant role in the rate of transpiration. As temperature increases, the rate of evaporation of water from the leaf surface also increases. This is because warmer air can hold more moisture, leading to a greater gradient between the moisture inside the leaf and the drier air outside. Therefore, higher temperatures generally lead to increased transpiration rates.

B. Affected by changes in light intensity

• Explanation: Light intensity affects transpiration because it influences the opening of stomata. In the presence of light, stomata typically open to allow for gas exchange (CO2 intake for photosynthesis), which also allows water vapor to escape. Thus, higher light intensity usually results in higher rates of transpiration due to increased stomatal opening.

C. Unaffected by humidity

• Explanation: This statement is incorrect. Humidity refers to the amount of water vapor present in the air. When humidity is high, the concentration gradient between the inside of the leaf (where the water vapor is) and the outside air (which is more saturated with water vapor) decreases. This reduced gradient slows down the rate of transpiration. Conversely, when humidity is low, the gradient is steeper, and transpiration rates increase. Therefore, humidity has a direct impact on the rate of transpiration.

D. Dependent on air movement

• Explanation: Air movement, or wind, can significantly affect transpiration rates. When air moves across the leaf surface, it helps to remove the water vapor that has just evaporated. This action maintains a steep concentration gradient, promoting further evaporation from the leaf. In still air, the water vapor can accumulate around the leaf, reducing the rate of transpiration. Thus, increased air movement generally leads to increased transpiration rates.

Summary of Incorrect Option:

• C. Unaffected by humidity is incorrect because humidity directly influences the concentration gradient for water vapor, which is crucial for transpiration. High humidity slows down transpiration, while low humidity increases it.

Revision Summary:

• Transpiration is influenced by temperature, light intensity, humidity, and air movement.
• Higher temperatures and light intensities increase transpiration rates.
• High humidity decreases transpiration rates due to a reduced concentration gradient.
• Air movement enhances transpiration by removing water vapor from around the leaf surface.

Understanding these factors is essential for grasping how plants regulate water loss and maintain homeostasis in varying environmental conditions.