Topic 6 Flashcards
Function of root hair cell
Allow the plant to absorb water
Root hair cell beneficial characteristics
Long projections that increase the surface are that the plant can use to absorb water and minerals
What don’t root hair cells contain
Chloroplast. Underground so no light for photosynthesis
Function of xylem cell
Transports water up the stem of a plant and into the leaves
What does lignin do
Strengthens the cell walls of xylem cells
What does stomata do
Make diffusion of gasses easier in leaves
What opens and closes the stomata
Guard cells
How do the guard cells close the stomata
They lose water and return to a limp state
How do the guard cells open up the stomata
Taking up lots of water causing them to swell
What happens with a lack of water
Stomata closes in order to prevent further water loss by guard cells returning to limp state
What does time of day have to do with stomata
Stomata closes at night as in the absence of sunlight, carbon dioxide is not required for photosynthesis
What does transpiration do
It transports water and the minerals dissolved in it through the plant
Direction of water
From the roots to the leaves
What process is used for root hair cells to absorb water from the soil
Osmosis
What happens once water reaches the leaves
Water evaporates and the water vapour diffuses out through open stomata
This loss of water is called transpiration
What affects rate of transpiration
Humidity
Air flow
Light intensity
Temperature
How does humidity affect rate of transpiration
Increased humidity increases amount of water in the air so harder for water to evaporate
Decreases rate of transpiration
How does air flow affect rate of transpiration
Increased air flow carries water away from the plants leaves so more water evaporates
Increased airflow means increase rate of transpiration
How does light intensity affect rate of transpiration
Increased light intensity makes water evaporate faster so increases rate of transpiration
How foes temperature affect rate of transpiration
Increase temperature makes water evaporate faster so increases the rate of transpiration
What apparatus is used to calculate rate of transpiration
Potometer
What do auxins do (plant hormones)
Change growth patterns to allow roots and shoots to move either towards or away from a stimulus
What do gibberellins do
Start of seed germination process
What does ethene do
Controls cell division
