Transport, Storage and Gas Exchange in Flowering Plants Chp24 Flashcards
What are the adaptations of root hairs for absorption
thin walls, not covered by cuticle, very numerous = large surface area
What path does water take to the xylem
absorbs into the root hairs and moves by osmosis into the ground tissue then the xylem
What is transpiration
the loss (by evaporation) of water vapour from the leaves and other aerial parts of a plant
What are the two ways water can move up the plant
root pressure and cohesion-tension model
Explain the events in root pressure
water is drawn into the root hairs and the build up of the water pushes the water up through the xylem
Outline the cohesion tension model
water evaporates from the leaves (transpiration), this pulls water up the xylem due to waters high cohesion (molecules stick together), water in the xylem is under tension as it is pulled upwards,
How do leaves control transpiration
waxy cuticle, stomata located on underside of the leaf, stomata surrounded by guard cells that open or close the stoma
How are minerals absorbed
in the roots by diffusion or active transport
How is carbon dioxide absorbed
comes through the stoma from the atmosphere or from respiration
What is the fate of the products of photosynthesis
oxygen released into the atmosphere or used in respiration, glucose used in respiration or stored as starch
Example of a modified root
carrot
Example of a modified stem
potato
Example of a modified leaf
onion bulb
What are lenticels
openings in the stems of plants that allow gas exchange
What is cohesion
the sticking together of similar molecules to each other
