Plant transport Flashcards
What does the Xylem consist of?
Thick walled dead cells which are hollow
Cell wall contains ligin (waterproofing)
What does the xylem transport?
Water and mineral ions from the roots to the leaves
What does the Phloem consist of?
Living cells. Tubes arranged end to end
What does the phloem transport?
Sucrose and amino acids from the leaves to the growing points or storage areas (roots or bulbs)
What is the function of the root hair?
Absorb water and minerals from the soil
What do root hair cells consist of?
Thin walled (short distance), hair like extensions which increase surface area
What is transpiration?
The evaporation of water from the surface of a plant
What is the function of transpiration?
to carry mineral ions to the leaves for the synthesis of amino acid and chlorophyll
Evaporation cools the leaf
What affects transpiration?
As temperature increases, transpiration increases
As humidity increases, transpiration decreases
As wind speed increases, transpiration increases
As Light intensity increases, transpiration increases
Why does temperature change transpiration?
On a hot day, water will evaporate quickly from the surface of the plant because the molecules have more kinetic energy. So transpiration increases
Why does Humidity change transpiration?
Humid air contains a great deal of water vapour, there is smaller concentration gradient, so transpiration slows
Why does light intensity change transpiration?
Stomata leaves are open in daylight to supply carbon dioxide for photosynthesis. So more water can diffuse out of the leaves
Why does wind speed change transpiration?
In windy conditions, the water vapour will be blown away as soon as it reaches the leafs surface. This will increase transpiration
What are stomata?
holes in the surface of the leaf
What are guard cells?
there are 2 guard cells found on either side of the stomata. They control the opening and closing of stomata.
