Exam #3 Key Terms Flashcards
when leaves and stems droop because the loss of turgid pressure with water
wilting
spaces between the cells that are dead tissues
apoplast
where water doesn’t cross the membrane
apoplastic pathway
where water crosses the membrane using plasmodesmata
symplastic pathway
channels that connect cells
plasmodesmata
when water crosses the membrane via diffusion
transmembrane pathway
barrier located in the radial walls of each endodermis cell is a belt made of suberin, a waxy material impervious to water and dissolved minerals. semi-permeable and only allows select solutes across.
Casparian strip
the process of transporting xylem sap involves the loss of an astonishing amount of water by water vapor leaves and other aerial parts of the plant.
transpiration
where water binds to water
cohesion
where water bind to other solute as it moves through
adhesion
the creation of negative pressure
tension
where transpiration provides the pull for the ascent of xylem sap, and the cohesion of water molecules transmits this pull along the entire length of the xylem from shoots to roots
cohesion tension model
movement of water and dissolved substances from the roots to the leaves of plants
transpiration stream
where water flows in from the root cortex and generates _____, creating a push of the xylem sap
root pressure
more water enter the leaves than transpired. This process can be seen in the morning on the tips or edges of some plant leaves
guttation
internal biological clock where cycles with intervals of approximately 24 hours
circadian rhythm
plants that are adapted to arid environments
xerophyte
typical plant photosynthetic pathway that endows plants with remarkable water use efficiency. Through the use of a carbon-concentrating mechanism,
crassulacean acid
transport of products of photosynthesis carried out by phloem.
translocation
aqueous solution that flows through sieves tubes differs markedly from xylem sap that is transported by tracheid and vessel elements
phloem sap
a plant organ that is a net producer of sugar, by photosynthesis or breakdown of starch
source
is an organ that is a net consumer or depository of sugar
sink
percolation of water through soil
leaching
plants are grown in mineral solutions instead of soil
hydroponic culture
plants need these in tiny quantities (chlorine, iron)
micronutrient
plants need these in relatively large amounts (carbon, oxygen)
macronutrient
contains rock fragments, and parent material. has water availability and cation exchange
C horizon
process in which cations are displaced from soil particles by other cations, particularly H+
cation exchange
a series of natural processes by which certain nitrogen-containing substances from the air and soil are made available to living things, are used by them, and are returned to the air and soil
nitrogen cycle
where plants start to turn yellow because chloroplast starts to die
Chlorosis
remains of dead organisms and other organic matter
humus
most fertile of topsoil which provides the most abundant growth
loam
mixture of particles derived from rock, living organisms, and decaying organic material
topsoil
conversion of atmospheric nitrogen (N2) to ammonia (NH3)
nitrogen fixation
where nitrogen compounds in the soil from dead animals and plants are converted into ammonia
ammonification
microorganisms that can convert atmospheric nitrogen into a form that plants can use for food
nitrogen-fixing bacteria
layer of soil beneath the topsoil
subsoil
top of the soil and is dominated by organic matter
O horizon
topsoil below O contains mostly roots
A horizon
where subsoil accumulates nutrients, woody roots
B horizon
bacteria that convert organic nitrogen in dead organisms to ammonium ions
ammonifying bacteria
process in which ammonium is converted to nitrite (NO2-) and then nitrate (NO3-)
nitrification
bacteria that convert organic ammonium to nitrate
nitrifying bacteria
