Transport in Plants

What is the pathway of water in plants?

Root hair cell to root cortex cells to xylem to leaf mesophyll cells

What is transpiration?

The loss of water vapour from plant leaves by evaporation of water at the surfaces of the mesophyll cells followed by diffusion of water vapour through the stomata

What are the functions of transpiration?

Transporting mineral ions, providing water to keep cells turgid to support the structure of the plant, providing water to leaf cells for photosynthesis, and keeping the leaves cool.

Where does water evaporate in a leaf?

Water evaporates from the surface of mesophyll cells into the air spaces of the leaf, this water vapor will diffuse out of the leaf through the stomata

What is the transpiration stream?

The transpiration stream is the upward movement of water through the xylem vessels

What is the transpiration pull?

When water is lost from the leaves, more water is drawn from the roots to replace it.

How does the transpiration pull work?

Each water molecule pulls on the molecules below it due to force of attraction between water molecules

How does wind speed affect the rate of transpiration?

High wind speed increases the rate of transpiration as more airflow removes water vapor from the air setting up a concentration gradient between the leaf and the air, increasing water loss.

How does humidity affect the rate of transpiration?

High humidity decreases the rate of transpiration, when the air is saturated with water vapor there is a reduced concentration gradient

How does temperature affect the rate of transpiration?

A high temperature increases the rate of transpiration as particles have more energy so it happens at a faster rate

What is translocation?

The transport of sucrose and amino acids in phloem from regions of production to regions of storage or use

What is the source of a plant?

A source is any photosynthetic part of a plant where a particular nutrient or food compound is produced or enters the phloem.

What is the sink of a plant?

A sink is the part of a plant where a particular nutrient or food compound is used, stored, or removed from the phloe