dicots - dicotyledonous plants
make seeds that contain two cotyledons. there are two types, herbaceous and arborescent
cotyledons
organs that act as food stores for the developing embryo plant and form the first leaves when the seed germinates
herbaceous dicotyledonous plants
soft tissue
relatively short life cycle
*leaves and stems die down at the end of each growing season
arborescent dicotyledonous plants
hard lignified tissue
long life cycles
vascular system
series of transport vessels running though the stems roots and leaves
turgor pressure
- result of osmosis in the plant cells
- provides hydrostatic skeleton to support the stems and leaves
- drives cell expansion enabling plant roots to force their way through tarmac and concrete
root hair
long thin extensions from a root hair cell
root hair cell
specialised epidermal cell found near the growing root tip
guttation
evidence of root pressure independent of transpiration
xylem sap exudes from the cut ends of the stems at certain times,
in nature, xylem sap forces out of special pores at the end of the leaves in some conditions eg overnight when transpiration is low
transpiration
the loss of water vapour from the leaves and stems of the plant. an inevitable consequence of gas ex
relative humidity
the measure of the amount of water vapour in the air compared to the total concentration water the air can hold
tranlocation
the transport of organic compounds from the sources to the sinks. an active process that requires energy to occur. bidirectional
xerophytes
plants that live in dry habitats that have evolved a wide range of adaptations that enable them to live and reproduce in places where water availability is very low indeed.
live in cold icy conditions or hot dry and breezy places
rhizomes
modified stems
hydrophytes
plants that live in water (surface/submerged/edge of bodies of water)
