Exam 4 Flashcards
internal functioning of plants
plant physiology
the movement of molecules from an area of higher concentration to an area of lower concentration
diffusion
diffusion of water across a semipermeable membrane
osmosis
different substances diffuse at different rates through this
semipermeable membrane
a mixture in which things are dissolved evenly
solution
the substance things are dissolved in
solvent
the thing dissolved in the solvent
solute
a solution with a solute concentration higher than the cell’s (cell would lose water)
hyptertonic
a solution with a solute concentration lower than the cell’s (cell would absorb water)
hypotonic
a solution with a solute concentration equal to the cell’s
isotonic
when the plasma membrane presses tightly against a cell wall, the plant cell is…
turgid
when the plasma membrane is not tightly pressed against a cell wall, the plant cell is…
flaccid
when the membrane pulls away from the cell wall altogether, which over time may kill the cell , the plant cell is…
plasmolyzed
how is water potential calculated?
water potential = pressure potential + solute potential
what is water potential?
the total pressure driving water in one direction or another
water always moves from an area of __ water potential to an area of __ water potential
higher, lower
what are the three main processes that move water through plants?
1) root pressure
2) capillary action
3) cohesion tension theory
stimulation of movement of water up the roots and lower stim due to
root pressure
the movement of water up a narrow tube due to polar bonding is known as
capillary action
a chain of water molecules joined by hydrogen bonds is pulled up the plant by evaporation through the leaves, this is known as
cohesion tension theory
the evaporation of water out of a leaf which drives water movement through the mesophyll is known as
transpiration
air bubbles break the tension (the pull) of the water column in xylem vessels; the air bubble is referred to as
embolism
the loss of xylem function due to embolism is called
cavitation
in small plants, repairing cavitation involves __ forcing gas bubbles to dissolve
root pressure
in larger plants, __ may be imported into the __ to get more water flow out by osmosis
solute, xylem
building new __ is also a way of repairing cavitation
xylem
when guard cells are __, the stomatal pore is open
turgid
when guard cells are __ or __, they lose __ pressure and close the stomata
flaccid, plasmolyzed, turgor
conserving water by closing stomata means absorbing less __ and usually __ __
co2, less growth
to open, guard cells absorb __ from nearby __ cells, then water flows into guard cells by __ to create turgor pressure in the cell
k+, epidermal, osmosis
guard cells export __ to become flaccid and close the stomatal pore
k+
some plant species have epidermal pores at the tips of veins called
hydathodes
some aquatic plants and plants from moist environments excrete excess water through __ which is called __
hydathodes, guttation
macronutrients include…
N, P, K, Ca, S, and Mg
what is nitrogen needed for?
proteins
deficiency of this nutrient shows as chlorosis (yellowing in older leaves)
nitrogen
phosphorus is needed for
nucleic acids & ATP
deficiency of this nutrient shows as green leaves with purpling
phosphorus
potassium is needed for
stress tolerance
deficiency of this nutrient shows as yellowing of leaf margins with spots
potassium
calcium is needed for
cell division, leaf expansion, & membrane transport
deficiency of this nutrient shows as dying leaf margins, small leaves, dead terminal buds/meristems, small roots and blossom end rot (can be caused by lack of water)
calcium
magnesium is needed for
chlorophyll & enzyme activity
deficiency of this nutrient can show as interveinal chlorosis with some spots and leaves curling
magnesium
sulfer is needed for
amino acids
deficiency of the nutrient sulfer can show as
small, light green leaves with some dead spots
to live, cells must have
energy
what is energy
the capacity to do work (moving objects) or to produce heat
what is the law of conservation of energy?
in nature, energy is neither created nor destroyed but is transferred between forms
what is metabolism?
the sum of all the interrelated biochemical processes that take place in an organism
the breaking or forming of chemical bonds in metabolism is done by
proteins called enzymes
what are the types of metabolism?
anabolism
catabolism
secondary metabolism
the building of molecules by forming chemical bonds
anabolism
the breakdown of molecules by breaking chemical bonds
catabolism
reactions that produce compounds not strictly necessary for normal growth, like latex or nicotine
secondary metabolism
chemical energy from food is transferred into chemical energy in ATP
cellular respiration
what is the overall equation for cellular respiration?
C6H12O6 + 6 CO2 + 6 H2O + 38 ATP
respiration uses oxygen so it is a __ reaction
aerobic
the three main components of cellular respiration are
glycosis
the krebs cycle
electron transport chain (ETP)
the __ is where most ATP is produced
ETP
why is ATP important for cells to function?
it is the source of energy for cells
what factors affect the rate of respiration?
temperature
oxygen levels
water levels
if the temperature is too high, the rate of respiration will
decline
without enough oxygen, the rate of respiration will
decline
since cells are mostly water, without enough water the rate of respiration will
decline
why is photosynthesis important to life on earth?
1) it produces 94% of dry weight in plants
2) it produced fossil fuels which provide 90% of the energy for electricity and transportation
3) it produces the world’s oxygen
this process converts light energy from the sun into chemical energy stored in sugars and other comounds
photosynthesis
what is the overall equation for photosynthesis?
6CO2 + 6H2O + light energy
–> C6H12O6 + 6O2
light is __ and it comes in __
energy, waves
light comes in individual particles called
photons
the color of light depends on __, which is the distance between two peaks in a wave
wavelength
when an object appears to be a certain color, it is __ that color/wavelength of light
reflecting
chlorophylls absorb light in the __ to __ and __ wavelengths
violet, blue, red
converts light energy absorbed by chlorophyll into chemical energy (ATP, NADPH)
in: light, water
out: ATP, NADPH, and oxygen as a waste product
light reactions
converts chemical energy in ATP & NADPH (short term) into chemical energy in carbohydrates (long term)
the calvin cycle
the carbon for making carbohydrates comes from __, and the enzyme responsible for this is __
co2, rubisco
__ and __ are the main parts of photosynthesis
light reactions, the calvin cycle
about 85% of plant species use only the __ photosynthesis pathway
c3
__ photosynthesis plants undergo __ __ __ for carbon fixation; these plants require cool and wet environments
c3, the calvin cycle
some plants use __ photosynthesis, which is highly efficient at using __; the most productive plants in the world use this
c4,co2
c4 photosynthesis requires a __ and __ environment and is found mostly in __
tropical, dry, monocots
in __ leaves, the __ __ __ are enlarged and have many chloroplasts, as well as all of the leaf’s __; this arrangement is known as __ __
c4, bundle sheath cells, rubisco, kranz anatomy
in __ photosynthesis, the __ captures co2 then pumps it into the __ __ __; the high concentration of co2 around __ makes photosynthesis run quickly and efficiently
c4, mesophyll, bundle sheath cells, rubisco
while mostly in monocots, __ photosynthesis is also important to some __ in __, __ environments
dicots, warm, dry
__ photosynthesis is a form of photosynthesis used by plants in arid environments to __ water
CAM, conserve
CAM stands for
crassulacean acid metabolism
in __ photosynthesis, the stomata are only __ at night
CAM, open
in CAM photosynthesis, __ is taken in at night through __, then stored in the __ of __ cells as __ acid
co2, stomata, vacuole, mesophyll, malic
in CAM photosynthesis, during the day, stomata are closed to __ water; in the __ __ __ a co2 is pulled of __ acid and fed into the __ __
conserve, bundle sheath cells, malic, calvin cycle
the majority of CAM plants are either __ __ or __ __ and __
desert succulents, epiphytic orchids, bromeliads
what is a heat-trapping, greenhouse gas?
co2
higher co2 impact on plant growth can
1) stimulate photosynthesis and growth
2) dilute tissue nutrients for herbivores
3) change competitive dynamics of species
the concentration of atmospheric co2 has increased by over __% since the beginning of the industrial revolution
40%
how does the increase in co2 affect horticulture?
1) shorter period for winter dormancy and stratification
2) select plant varieties become more tolerant to heat and drought
3) extended growing season + stormwater management
an irreversible increase in size due to the division and enlargement of cells
growth
a change in form as a result of both growth and differentiation
development
growth and development are regulated by
hormones
__ are molecules that are usually transported in an organism and have specific effects on growth, flowering, and other plant activities
hormones
__ are a plant hormone produced in the shoot apical meristem, buds, young leaves and other young actively growing plant parts
auxins
auxins were discovered by
frits went
enlargement of cells by elongation of cell walls, which causes coleoptiles to bend; cells longer on one side than the other
what plant hormone is this a function of?
auxins
auxins produced in the __ __ __ inhibit growth of lateral buds (this is responsible for __ __)
shoot apical meristem, apical dominance
__ can stimulate the differentiation of new __ __ including the growth of new __ from stem cuttings, and the differentiation of __ cells into different cell types (__, __)
auxins, cell types, roots, parenchyma, roots, xylem
auxins can delay developmental processes such as
fruit and leaf abscission and fruit ripening
auxins can be sprayed in __ to prevent __ __ so they can all be harvested at the same time
orchards, fruit abscission
__ can be sprayed on flowers to produce __ fruits
auxins, seedless
auxins in high concentrations will __ plants, but some plants require more than others
kill
__ is a plant hormone produced by fungi and discovered by eiichi kurosawa
gibberellin
gibberellins (GA) are produced in
immature seeds
root and shoot tips
young leaves
gibberellin (GA) __ growth primarily in __
enhances, dicots
gibberellin __ seed germination by __ the breakdown of stored __ in the seed
spurs, stimulating, carbohydrates
gibberellin __ flowering in some species
stimulates
gibberellin can __ the temperature threshold of __ __ (grow more at __ temps)
lower, plant growth, cooler
GA revolutionized the production of __ __; fruit __ were longer, providing more __ __ and reducing __ __
seedless grapes, internodes, air flow, fungal growth
__ are a plant hormone discovered by Gottlieb Haberlandt
cytokinins
this plant hormone is a chemical in phloem that stimulates cell division and the production of cork cambium
cytokinins
cytokinins can stimulate __ __ but only in the presence of __
cell division, auxin
cytokinins are a chemical found in __
phloem
in tissue culture, __ and __ are added to a few cells to grow a whole plant
auxins, cytokinins
__ delay ageing so it is often applied to __, __ __, and __ __
cytokinins, leaves, cut flowers, harvested veggies
__ __ (ABA) is a plant hormone discovered by Torsten __
abscisic acid, hemberg
__ are substances from dormant buds and can block the effects of __
ABA, auxins
abscisic acid can __ seed germination, opposing the effects of __ and __
inhibit, gibberellin, cytokinins
__ is present in high concentrations in __ to prevent germination and can be applied __
ABA, fruits, externally
ABA produced in response to drought causes __ __, in addition ABA produced during drought can stimulate __ __
stomatal closure, root growth
__ is the only gaseous hormone, and is a simple molecule given off by __ __
ethylene, ripening fruits
ethylene functions to initiate __ of leaves and flowers and arrest __ __ resulting in __, sturdier plants
abscission, cell elongation, shorter
__ are permanent movements resulting from external stimuli coming from one direction, so the plant is growing towards or away from a particular __
tropisms, stimulus
__ is the growth of plants towards or away from light
phototropism
__ __ is growth towards light
positive phototropism
__ __ is growth away from light
negative phototropism
__ is when plants grown in the dark develop long stems, few leaves and pale appearance
etiolation
__ is the growth of plants towards or away from gravity
gravitropism
__ gravitropism is growth towards gravity
positive
__ gravitropism is growth away from gravity
negative
the effects of etiolation
long stems
few leaves
pale appearance
gravitropism is thought to be mediated by __ which move when the plant is flipped
amyloplasts
response of plants to the respective lengths of night and day
photoperiodism
the daytime of photoperiodism is called the
photoperiod
the nighttime of photoperiodism is called the
skotoperiod
plants can sense and respond to photoperiod using two pigment molecules, which are
phytochrome
cryptochrome
is necessary for plants to flower on the proper photoperiod
phytochrome
plants will flower if they have a single __
leaf
__ __ plants require a photoperiod of 10 hours or less to flower
short day
__ __ plants require a photoperiod of 12-14 hours to flower
long day
__ __ plants will flower only if one leaf is exposed to a short 8hr photoperiod
short day
photoperiod is sensed in the __ but the signal is transmitted to the buds somehow, the unknown hormone was dubbed __
leaves, florigen
