Plant structures and their functions Flashcards
temperature (Affect transpiration)
The higher the temperature, the more energy water molecules have
Which means a faster rate of transpiration
air movement (Affect transpiration)
Wind blows moist air away from the stomata
Which keeps the diffusion gradient high
Light intensity (Affect transpiration)
High light intensity causes the stomata to open
This increases the rate of evaporation from water from the leaft
Describe how you could use this investigation to show that sucrose can move both up and down the plant
This will be shown if radioactivity can be detected both above and below the leaf being supplied with radioactive Co2
Translocation
Translocation is the transport of sucrose and other nutrients in a plant
Stomata
Stomata are found mainly on the lower surface of the leaf
Stomata is a tiny opening found inside the plant
Transpiration system
The movement of water from the roots to the leaves is called the transpiration stream
Transpiration
Transpiration is the loss of water by evaporation from the leaves
Sucrose
Sucrose is translocated around the plant in the phloem sieve tubes
Xylem
Xylem vessels are dead cells which have no cytoplasm or cell contents
They have holes called pits in their walls to allow the flow of water
Walls are strengthened with lignin rings
Phloem
contains sieve tube elements which have very little cytoplasm
also contains companion cells which have lots of mitochondriab
Carbon dioxide concentration
Co2 is a limiting factor because an increase in its concentration increases the rate of photosynthesi
Temperature (Photosynthesis)
if the temperature is too high, enzymes start to denature
temperature is a limiting factor because an increase in temperature increases the kinetic energy of molecules
Limiting factors of Photosynthesis
Low temperature
dim light
low carbon dioxide
Photosynthesis equation
carbon dioxide + water - Light energy, glucose + oxygen
