Epidermis of Leaf and Stomata

The epidermis is the outermost layer of a leaf that protects it from water loss and external damages. The epidermis also contains small pores called stomata which are responsible for the exchange of gases and water vapor between the leaf and the atmosphere. Stomata are essential for the process of photosynthesis and respiration in plants.

Answer Explanation

The correct answer is option 'A', which states that the abaxial epidermis of the leaf contains more stomata than the adaxial epidermis. The abaxial epidermis is the lower surface of the leaf, while the adaxial epidermis is the upper surface.

Explanation

Several factors can affect the distribution and density of stomata on the leaf epidermis. Some of these factors include:

1. Light intensity: Stomata are more abundant on the abaxial epidermis of the leaf when the light intensity is low. This is because the abaxial epidermis has a higher capacity for photosynthesis than the adaxial epidermis.

2. Temperature: Stomata are more abundant on the adaxial epidermis of the leaf when the temperature is high. This is because the adaxial epidermis is better suited for transpiration and cooling the leaf.

3. Humidity: Stomata are more abundant on the abaxial epidermis of the leaf when the humidity is low. This is because the abaxial epidermis can prevent excessive water loss through transpiration.

4. Leaf orientation: In some plants, the leaf orientation can affect the distribution of stomata. For example, in some desert plants, the leaves are oriented vertically to reduce exposure to direct sunlight and reduce water loss. In such plants, the stomata are more abundant on the abaxial epidermis.

Conclusion

In conclusion, the abaxial epidermis of the leaf contains more stomata than the adaxial epidermis. The distribution and density of stomata on the leaf epidermis can be influenced by several factors, including light intensity, temperature, humidity, and leaf orientation.

Stomata helps plants to absorb CO2 from the environment.They need to be protected from sun to reduce excessive loss of water vapour.Hence they are present on the lower surface of leaves which is away from sunlight. This type of leaves are known as abaxial leaves.