Answer is 3.....As plants transpire, the humidity around saturates leaves with water vapor. When relative humidity levels are too high or there is a lack of air circulation, a plant cannot make water evaporate (part of the transpiration process) or draw nutrients from the soil. When this occurs for a prolonged period, a plant eventually rots. When surrounded by warm temperatures in low relative humidity levels, transpiration rates in a plant increase, reducing the need for a grower to fertilize it.

Effect of 100% Relative Humidity on Open Stomata

Introduction:
Stomata are tiny openings found on the surface of plant leaves and stems. They play a crucial role in the exchange of gases, such as carbon dioxide and oxygen, as well as the regulation of water vapor. The opening and closing of stomata are influenced by various environmental factors, including relative humidity.

1. Completely Open Stomata:
When the relative humidity reaches 100%, the air is already saturated with moisture, meaning it cannot hold any more water vapor. In such conditions, the plant's stomata will remain completely open. This is because the plant does not need to conserve water through closing the stomata when the air is already saturated. The fully open stomata allow for gas exchange and transpiration to occur freely.

2. Partially Open Stomata:
Under certain circumstances, the stomata may be partially open even when the relative humidity is at 100%. This can happen due to other factors influencing stomatal behavior, such as light intensity and carbon dioxide concentration. If there is a high light intensity, the stomata may remain partially open to allow for photosynthesis to continue, even in humid conditions.

3. Closed Stomata:
In normal conditions, when the relative humidity is below 100%, plants tend to close their stomata to limit water loss through transpiration. However, when the relative humidity reaches 100%, there is no need for the plant to conserve water through stomatal closure. Therefore, in most cases, the stomata will remain open or partially open rather than completely closed.

4. Partially Open or Closed Stomata:
Although it is unlikely, there may be some instances where the stomata are partially open or closed even at 100% relative humidity. This could be due to other factors at play, such as the plant's genetic traits or specific adaptations to its environment. However, such occurrences would be rare and not the typical response of most plants.

Conclusion:
In summary, when the relative humidity reaches 100%, the stomata of most plants will either be completely open or partially open. This allows for gas exchange and transpiration to continue, as there is no need for water conservation in saturated air. However, there may be exceptional cases where stomatal behavior deviates from this general response.