17) Transpiration and Translocation

What do phloem tubes transport?

Food substances, mainly dissolved sugars, from the leaves to other parts of the plant.

What is translocation?

The process of transporting food substances in both directions through phloem tubes.

Describe the structure of xylem tubes.

Made of dead cells with no end walls, creating a continuous tube, strengthened by lignin.

What do xylem tubes transport?

Water and mineral ions from the roots to the stem and leaves.

Define transpiration.

The loss of water vapor from a plant, primarily through the leaves.

How does transpiration create a water shortage in leaves?

Evaporation of water from the leaf surface causes a slight shortage, leading to more water being drawn up from the xylem.

What is the transpiration stream?

The continuous movement of water from the roots, through the xylem, and out of the leaves

Why do leaves have stomata?

To facilitate gas exchange necessary for photosynthesis.

What causes water to escape through the stomata?

There is a higher concentration of water inside the plant than in the outside air, leading to diffusion.

What role do root hair cells play in transpiration?

They are adapted to take up water, supporting the transpiration stream by drawing water from the soil.