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56 terms

Plants & Humanity

Exam 2
functions of stems
attachment & support of leaves, flowers, fruits
underground horizontal stem (different from roots - leaf scars, axillary buds, nodes, internodes)
storage organs at tip of underground stems (white potato)
pores all over the wood for cambium "breathing"
cell theory
if you slice smaller and smaller, the smallest reproducible unit is the cell
electron microscope vs light microscope
electron = 1 millionx
thick walls, dead at maturity, support & protection
wood, pits, seed covers
unevenly thick walls, alive, support of non-woody tissues
found on edges of non-woody stems
thin walled, metabolically active
food synthesis, storage, secretion
transfer cells
feathery finger-like ingrowths on parenchyma cells that provide short distance intensive transport
increase surface area of cell membrane
phloem is eaten away and roots cut off from sugar
packages stuff
makes proteins
wood, water transport
bark, sugar transport
storage sacs for sugars, pigments, waste
protection from grazers, found in acorns & olives
sugar manufacturing
CO2+H2O -> C6H12O6+O2
glucose+oxygen -> carbon dioxide + water + ATP
cyanide blocks metabolic pathway
Ca-ox crystals that can be used to archaeology
photo-reversible molecule that picks up light
P-red -> P-far red
ovary w/ seed
climactic fruits
ripening w/ ethylene gas
apple, avocado, cantaloupe
plant growth regulator
bending towards light, redistribution of auxin to shaded side to create asymmetric growth
gibberellic acid
plant growth regulator, juvenility hormone, produced in the roots so oldest, lower branches of the tree are in juvenile phase, internode elongation
immobile nutrients
immobile in the phloem, symptoms will occur in young top leaves
Ca, B, Fe, S
mobile nutrients
mobile in the phloem, symptoms will occur in older bottom leaves
dry areas that are irrigated, combined w/ evaporation end up with salt soils -> decline in fertility
top layer of soil w/ the most organics
zone of leaching
mineral rich zone
zone of deposition
rocks, parent material
functions of roots
attract microbes
functions of leaves
manufacture food
absorb CO2
release water vapor
reflect light
central mother cell zone
center circular portion of cells in the middle of apical meristem, reserve of cells in case others get damaged
peripheral zone
most dense area of cells immediately surrounding the mid meristem - initiating ring
makes cortex, stem
rib meristem
lower center of stem, distinct empty cells in rows that make up the stalk
makes pith, stem
serially arranged supernumerary buds
stacked on top of one another - air potato, Bougainvillea
collaterally arranged supernumerary buds
aligned in a row along leaf scar - garlic
5 types of modified branches
fruit spurs, food storage (air potato, garlic), flowers, runners & stolons (strawberry), thorns (Bougainvillea)
4 characteristics of leaves
lateral organs of the shoot system
determinate (limited) growth
has an upper & lower side
arise superficially from shoot apex
leaf growth: marginal vs intercalary
marginal = broad leaves, dicots
intercalary = narrow leaves, monocots, grasses
differences beween monocot & dicot leaf anatomy
monocot veins are parallel
monocots have bulliform cells in upper epidermis
monocots have homogenous mesophyll (no upper & lower)
intercalary growth
characteristics of bogs
wet, low oxygen, mineral poor, rich in light, acidic, low decay rates
plants have minimal root systems & specialized leaf systems
Drosera (sundew)
sticky red trichomes on leaves attract & trap flies, leaf engulfs fly for nitrogen
Dionaea (venus fly trap)
red color inside leaf blade, when fly touches trigger hair twice trap closes
Sarracenia (pitcher plant)
leaves are conical & hold water
fly follows the red nectar guides down to the slippery cuticle where they grab onto downward pointing hairs & slip into the fluid & drown
plant that grows on another for support (usually sunlight), more prevalent in tropics because exposed roots mild climate
compensatory growth
one system makes up for lacking systems - epiphytes have increased leaf component & reduced root system
basket plant
funnel collects litter which decays & provides nutrients
tank epiphyte
bromeliads, cisterns, leaves closely associated on stem so water & litter collect
T-shaped hairs collect water
air plants
Spanish moss, dangles off branches, no roots, stem-branch-leaf system covered in t-shaped hairs to absorb runoff water
5 common features of roots
apical meristem is subterminal
apical meristem is covered by root cap
root hairs present
endogenous branching (branching starts vein)
xylem & phloem on alternate radii
single cell layer in the root cortex responsible for endogenous branching
root modifications
epiphytic orchids - climbing roots, photosynthesis, water storage
ficus - butress roots, stilt roots
mangrove - prop roots, cable roots, pneumatophores
orchid root epidermis multiplies into multiple epidermis
spongy, soaks up water
vascular cambium
ring of cells the differentiate into xylem & phloem
only found in dicots
tree rings