Ch. 39 Plant Nutrition Flashcards
essential nutrient
any chemical element, ion, or compound that is required for normal growth, reproduction, and maintenance of a living organism
- cannot be synthesized by the organism
examples of essential nutrients
1) carbon
2) hydrogen
3) oxygen
ways to obtain essential nutrients
1) from water
2) from the air
3) from the soil
macronutrient
any element that is required in large quantities for normal growth, reproduction, and maintenance of a living organism
- major components of nucleic acids, proteins & phospholipids
examples of macronutrients
1) nitrogen
2) phosphorus
3) potassium
limiting nutrient
any essential nutrient whose scarcity in the environment reduces growth & reproduction of organisms
examples of limiting nutrients
nitrogen
phosphorus
potassium
micronutrient
any element that is required in very small quantities for normal growth, reproduction, and maintenance of a living organism
- function as cofactors of specific enzymes
examples of micronutrients
iron
boron
copper
nickel
nitrogen deficient plant
yellowing of leaves
phosphorous deficient plant
stunted growth
dead spots
brown
mobile elements
nitrogen / potassium / phosphorous
when limited, they are transferred from older leaves to newer leaves
scarcity reflected in determination of older leaves
immobile elements
calcium / iron / copper
remain tied to older leaves
scarcity is reflected in newer leaves
hydroponic growth
growth of plants in liquid cultures instead of soil
weathering
gradual wearing down of large rocks by rain, running water, temperature changes, and wind
- one of the processes that transform rocks into soil
flakes & pebbles (weathering)
break off from the solid rock
- the first ingredients in soil
humus
decayed organic matter in soils
texture
quality of soil, resulting from relative abundance of different-sized particles
proportions of gravel, sand, silt, and clay
soil texture affects:
1) penetration of soil
2) soil’s ability to hold water
3) availability of oxygen
mature soil
a complex mixture of organic and inorganic components
loam
soil that contain equal amounts of soil, silt & clay w/ a high proportion of humus
- best soil
- contain organic matter
- good texture
sustainable agriculture
agricultural techniques that are designed to maintain long-term soil quality and productivity
leaching
loss of nutrients from soil via percolating water (washing)
anion
ions with negative charges
- usually dissolve in soil water
- interact with water molecules via hydrogen bonding
cation
ions with positive charges
- dissolve in soil water
- not as immediately available as anions
examples of sustainable agriculture
1) planting rows of trees as windbreaks
2) minimizing the amount of plowing & tilling needed to control weeds
3) planting crops in strips that follow the contour of hillsides
ion
charged particle
role of soil pH
low pH = acidic (high concentrations of hydrogen ions)
high pH = basic / alkaline (few hydrogen ions)
cation exchange
displacement of protons or cations by protons in soil water
- released cations available for plant uptake
zone of maturation
(in plant roots) a group of plant cells located several millimeters behind the root cap
- they are differentiating into mature tissues
- nutrient uptake occurs here
root hair
extensions of the epidermal cells in the zone of maturation
membrane potential
a difference in electric charge across a cell membrane
- a form of potential energy
aka membrane voltage
symbiotic
“living together”
any close and prolong physical relationship between individuals of 2 different species
mutualistic
organism that is a participant and partner in a mutualistic relationship
- mutually beneficial
metallothionein
small plant protein that bind to & prevent excess metal ions from acting as toxins
- active exclusion
- requires energy
tonoplast
membrane surrounding the large, central vacuole
ectomycorrhizal fungi (EMF)
fungi that have hyphae that wrap around the epidermal cells of roots
arbuscular mycorrhizal fungi (AMF)
fungi that have hyphae that can penetrate the walls of plant root cells
nitrogen fixation
the incorporation of atmospheric nitrogen (N2) into ammonia (NH2), which can be used to make many organic compounds
- occurs in only a few lineages of bacteria & archaea
nodule
globular structure on roots of legume plants that contain symbiotic nitrogen-fixing bacteria
look like little moles on the roots
leghemoglobin
iron-containing molecule similar to hemoglobin
- found in infected cells of legume root nodules
- oxygen binding
- creates pink coloration
nod factor
molecule produced by nitrogen-fixing bacteria that help them recognize & bind to roots of legumes
epiphytic plant
“upon plants”
a nonparasitic plant that grows on the trunks or branches of other plants
- not rooted in soil
where do epiphytes get their nutrients?
from rainwater, dust & particles that collect in their tissues and crevices of bark
parasite
an organism that lives on a host species (ectoparasite) or in a host species (endoparasite)
- damages the host
carnivorous plant
plants that use modified leaves to trap insects & other animals
- make their own carbohydrates via photosynthesis
- use carnivory to supplement the nitrogen available in the environment
