gas exchange in plants

Where does photosynthesis mainly occur in a leaf?

In the palisade mesophyll.

How does photosynthesis affect oxygen and carbon dioxide concentrations in leaves?

It uses carbon dioxide and produces oxygen, creating concentration gradients.

How does oxygen leave a leaf?

Oxygen diffuses from the mesophyll air spaces through the stomata into the atmosphere.

How does carbon dioxide enter a leaf?

Carbon dioxide diffuses from the atmosphere through the stomata into the leaf

What are stomata?

Pores that allow gas exchange between the leaf and the atmosphere

What are guard cells?

Cells surrounding stomata that control their opening and closing

Why do stomata close at night?

To reduce water loss by evaporation when photosynthesis is not occurring

What are xerophytic plants?

Plants adapted to survive in environments where water is limited

How do curled leaves reduce water loss?

Trap moist air, increasing humidity around stomata and reducing evaporation

How do sunken stomata reduce water loss?

Trap moist air around stomata, increasing local humidity and reducing evaporation

How does a thicker cuticle reduce water loss?

Provides a waterproof barrier that reduces evaporation from the leaf surface

How do hairs on leaves reduce water loss?

Trap moist air around stomata, increasing humidity and reducing evaporation

How do longer root networks help xerophytes survive?

Allow the plant to reach and absorb water from a larger volume of soil