TRANSPIRATION/TRANSLOCATION

Where does translocation occur

phloem

Where does transpiration stream occur

xylem

How does cell sap move throughout the phloem

Phloem cells contain sieve plates + pores

What is cell sap

A liquid mixture of water + sugars

What is sugar from translocation used for

Energy for respiration

Stored as cellulose

Is translocation monodirectional or bidirectional

Bidirectional

What is translocation

Movement of dissolved sugars from the leaves to the rest of the plant

What is the transpiration stream

Chain of water molecules from roots up to the leaf through the xylem

What is transpiration

Evaporation of water out of leaves

What are the products of transpiration used for

Photosynthesis

How is water transported up the plant

Via the transpiration stream through the xylem

How does the transpiration stream work

Every time a water molecule evaporates out of the leave it pulls the chain of molecules up and is replaced

How is the rate of transpiration increased

High light intensity

High temperature

High wind intensity

Low humidity

Why does high light intensity increase rate of transpiration

More Light

More photosynthesis

More stomata open for CO2

More water evaporates out of stomata

Why does high temperature increase rate of transpiration

Higher temperature

More energy in water molecules

More water is likely to evaporate out of stomata

Why does high wind intensity increase rate of transpiration

More wind

Water that leaves the leaf is quickly blown away

Maintains high concentration gradient for diffusion

Why does low humidity increase rate of transpiration

Less water molecules outside plant

Maintains high concentration gradient for diffusion