B3.2 HL Transport in Plants [IB Biology HL]

What initiates transpiration in plants?

Transpiration initiates when water vapor evaporates from the stomata.

What are stomata?

Stomata are openings on the underside of the leaves that allow gases in and out, and water leaves.

What happens to transpiration when the outside air is humid?

Transpiration will cease when the outside air is humid.

What is the role of active transport in water movement through plants?

Active transport pumps mineral ions from the soil into the roots, allowing water to enter by osmosis.

What are the two main types of vascular tissue in plants involved in transport?

The two main types are xylem and phloem.

How does phloem transport materials?

Phloem transports materials from source to sink, which can be upward, downward, or across.

What is phloem loading?

Phloem loading is the active transport process of pumping carbon compounds into the phloem.

What is hydrostatic pressure in the context of phloem?

Hydrostatic pressure is the pressure created by a high concentration of water and solutes in the phloem.

What are companion cells' functions in the phloem?

Companion cells assist in the phloem loading and the active transport of carbon compounds to the sink.

Why must phloem rely on companion cells during transport?

Phloem cells disintegrate and lose organelles, so they require companion cells for active transport functions.