Unit 3 - Transport in Plants Flashcards
What is the transpiration stream?
The path water takes through a plant
What is the transpiration stream driven by?
Evaporation taking place at the leaves
How can traspiration be sped up? (what conditions)
In warm/windy conditions, these will speed up evaporation and therefore transpiration
How do warm conditions speed up transpiration?
Gives water kinetic energy
How do windy conditions speed up traspiration?
It increases the water gradient from inside the outside of plants (eg the moisture doesnt get trappen around the clothes)
Where does the second system of transport around a plant take place? What is it?
In the phloem tubes, they transport sugar around the plant for use in respiration
What do the xylem tubes?
Carry water and minerals from the rots to the stem and leaves in the transpiration stream
(exam answer) Explain the whole transpiration stream
Starts in the plant roots when water is absorbed by root hair cells
The water moves into hollow tubes called xylem vessles
The xylem transport water and mineral ions up the stem of the plant forming vascular bundles
The xylem vessles loose water in the leaf
In the leaf air spaces in the spongy mesophyll later become saturated with water
Water evaporates through the stomata and more water is drawn through the roots
Where do plants exchange gases with the environment?
Through their leaves
What are the stomata?
Holes (mostly) on the underside of the leaf. They can be open and closed by the guard cells that surround them
Plants can close stomata when they want to reduce transpiration
What does the top layer of the leaf deal with
Photosynthesis
What does the lower part of the leaf deal with
Gaseous exchange
