Gas Exchange in Leaves

What is the function of the waxy cuticle in leaves?

It reduces water loss and protects the leaf.

Why does the waxy cuticle limit gas exchange?

It is waterproof and restricts diffusion of gases.

What is the role of the epidermis in leaves?

Protection and housing stomata for gas exchange.

What are stomata?

Pores that allow CO₂ to enter and O₂ and water vapor to exit the leaf.

Which cells control the opening and closing of stomata?

Guard cells.

What is the function of spongy mesophyll?

It provides air spaces for diffusion of gases.

Why are air spaces important in leaves?

They allow gases to diffuse efficiently within the leaf.

How do veins support gas exchange in leaves?

They transport products and maintain concentration gradients.

What is transpiration?

The loss of water vapor from stems and leaves.

Through which structure does most transpiration occur?

Stomata.

What role do cohesion and adhesion play in transpiration?

They allow continuous water movement without energy input.

Name four factors that affect transpiration rate.

Temperature, humidity, light intensity, and wind exposure.

How does increased temperature affect transpiration?

It increases the rate of transpiration.

How does high humidity affect transpiration?

It decreases the rate of transpiration.

How does increased light intensity affect transpiration?

It increases transpiration by opening stomata.

How does wind affect transpiration?

It increases transpiration by removing water vapor near the leaf.

What is stomatal density?

The number of stomata per unit area of a leaf.

Why does stomatal density vary?

It varies between species and environmental conditions.