chapter nine: water in plants Flashcards
elements that are vital for a plants metabolism, growth, and reproduction
essential nutrients
___ elements are required by plants; ___ macronutrients and ___ micronutrients
16
9
7
9 macronutrients that a plant needs
C, H, O, P, K, N, S, Ca, Mg
7 micronutrients that a plant needs
Cl, Fe, B, Zn, Mn, Cu, Mo
deficiencies in nutrients produce ____
distinct symptoms
plants obtain nutrients from ___ and ___
atmosphere and soil
main nutrients obtained from the atmosphere are ___ and ___ from ___
C and O from CO2
nutrients are mainly obtained in the soil in the form of ____, ___, and ___
minerals, H2O, and O2
how does dead organic matter get transferred into mineral inorganic matter
active decay promoted by decomposers
plants obtain nitrogen from the soil with the help of ___ and ___
certain bacteria and decomposers
most plants take up nitrogen in the form of ___ or ___
NH4+ or NO3-
nitrogen fixing bacteria that infects leguminous plants, triggering the development of root nodules
rhizobium
water and dissolved minerals go from roots to shoots under ____ cause by ___
negative pressure
transpiration
three steps of movement of water and dissolved minerals
- transpiration
- replacement of transpired water
- uptake of water by roots
water evaporates via transpiration due to a steep ____
diffusion gradient (leaf interior has higher moisture content than atmosphere)
transpired water is replaced by water traveling upward through ___; ___ and ___ of water allow for this, and this is known as the ____
xylem
cohesion and adhesion
cohesion-tension theory
water that travels upward through xylem is replaced by ___
water from the soil
water diffuses into roots because ____
solute concentration in root cells is higher than that in the soil
water entering roots can move through cortex by these two routes
apoplastic (extracellular) pathway
symplastic (intracellular) pathway
___ is a positive pressure that can help contribute to the movement of water through the plant, but is not as important as ___
root pressure
transpiration
anything generated from photosynthesis, primarily sugar
photosynthate
photosynthates travel from ___ to ___ under ___ pressure
source to sink
positive pressure
where glucose is made or stored; where sugar is loaded into phloem
source
where glucose will be used, where the bonds will be broken; where sugar is removed from phloem
sink
3 steps of loading photosynthates into phloem at the source
- solutes enter a sieve tube by active transport
- water enters sieve tube from the xylem by osmosis, increasing pressure in the sieve tube
- this pressure pushes the solute toward the sink
2 steps of unloading photosynthates from phloem at the sink
- as sink is reached, solutes are unloaded by passive diffusion
- water moves out of phloem to the xylem by osmosis, decreasing pressure in the sieve tube
loading and unloading happens in which direction?
both; roots to shoots and shoots to roots
loading and unloading is regulated by ___ and ___
hormones and enzymes
