Exam 1 Flashcards
the scientfic study of the abundance and distribution of organisms in relation to other organisms and environmental condition
ecology
true or false: the notion of “the balance of nature” is ecologically valid
false
what does the balance of nature assume
the system is stable or static and all species are equal
the system of balance of nature is
dynamic
ideas of ecology (4)
ecological interactions
scale matters
energy flows, nutrients cycle
evolution
qualities of ecological interactions
stabilizing
amplifying
vary substantially
levels of ecological organization (smallest to largest)
individual
population
community
ecosystem
landscape
biosphere
the unit of natural selection
individual
the unit of evolution
population
states body size should increase with latitude
Bergmann’s Rule
composition and configuration of land uses can affect ecological processes
landscape ecology
connect all parts of the biosphere
biotic and abiotic processes
the range of abiotic and biotic conditions an organism can tolerate (ex: temperature and humidity, food it can eat)
niche
each species has a distinct
niche
the place, or physical setting, in which an organism lives
habitat
consumers of dead matter
scavengers, detritivores, and decomposers
consume dead animals (ex: vultures)
scavengers
break down dead organic matter and waste products (detritus) into smaller particles (ex: millipedes and dung beetles)
detritivores
break down dead organic material into simpler elements and compounds that can be recycled through the ecosystem (ex: many species of mushrooms)
decomposers
interactions in which two species live in close association and one species receives a benefit, while the other experiences neither a benefit nor a cost
commensalism (+/0)
a close relationship between two different types of organisms
symbiotic relationship
when two species interact in a way such that each species receives benefits from the other
mutualism (+/+)
an interaction with negative effects on both species that require the same limited resource to grow, survive, and reproduce
competition (-/-)
organisms that consume producers, such as plants and algae
herbivores (+/-)
a disease causing microbe
pathogen
organisms that live in or on another organism, called the host; individual ones of these rarely kill its host
parasites (parasitism +/-)
organisms that kill or entirely consume another individual (prey)
predators (+/-)
a special kind of predator that lives within and consumes the tissues of a living host, eventually killing it
parasitoids
organisms that use photosynthesis to convert solar energy into organic compounds or use chemosynthesis to convert chemical energy into organic compounds
ex: chemosynthetic archaea and bacteria, cyanobacteria, most algae, most plants
producers
organisms that obtain their energy from other organisms
ex: fungi, bacteria, herbivores, and carnivores
heterotrophs
species that obtain their sources of carbon through a mixed approach of obtaining their energy
ex: carnivorous plants that obtain their energy both form photosynthesis and from consuming invertebrates, algae
mixotrophs
true or false: species evolve in isolation
false
a change in frequency of genes in a population through differential survival and reproduction of individuals that possess certain phenotypes
natural selection
what does natural selection depend on (3)
-individual organisms vary in their traits
-parental traits are inherited by their offspring
-the variation in traits cause some individuals to experience higher fitness
the survival and reproduction of an individual
fitness
phenotypes are determined by the interaction of
the organism’s genotype with the environment in which it lives
a change in the genetic composition of a population over time
evolution
an organisms behavior, morphology, or physiology
phenotype
the set of genes an organism carries
genotype
when the gains and losses of ecological systems are in balance
dynamic steady state
how are dynamic steady states achieved on an individual basis
assimilated food and energy must balance energy expenditure and metabolic breakdown of tissues
how are dynamic steady states achieved on a population level
population increases with births and immigration, and it decreases with death and emigration
how are dynamic steady states achieved in a community
the number of species living in a community decreases when a species becomes extinct and increases when a new species colonizes the area
how are dynamic steady states achieved in ecosystems and landscapes
energy and matter enter and leave ecosystems and move among multiple ecosystems in landscapes
how are dynamic steady states achieved in biospheres
the biosphere receives energy from the Sun, and this gain of energy is balanced by heat energy radiated by earth back out into space
energy cannot be created or destroyed, only can be converted into different forms
the law of conservation of energy (first law of thermodynamics)
matter cannot be created or destroyed, but can only change form
the law of conservation of matter
life builds on the physical properties and chemical reactions of
matter
this approach to ecology is concerned with the largest scale in the hierarchy of ecological systems
tackles the movements of air and water–and the energy and chemical elements that they contain–over earth’s surface
includes all the ecosystems and landscapes on earth
biosphere
all transformations within the biosphere are internal with what two exceptions?
the energy that enters from the Sun and the energy that is lost to space
this approach to ecology is concerned with the movement of energy, matter, and individuals between ecosystems
includes multiple ecosystems that are connected by the movement of individuals, populations, matter, and energy (ex: aquatic and terrestrial ecosystems); can also include patchworks of different communities
landscapes
this approach typically focuses on the movement of energy and matter between physical and biological components of the ecosystem
composed of one or more communities of living organisms interacting with their nonliving physical and chemical environments, which include water, air, temperature, sunlight, and nutrients
ecosystem
composed of all populations living together in a particular area and interact with each other in various ways, influencing the number of individuals in each population
this approach is concerned with the understanding of the diversity and relative abundances of different kinds of organisms living together in the same place
community
consists of individuals of the same species in a living area
examines variation over time and space in the number of individuals, the density of individuals, and the composition of individuals (sex ratio, distribution of individuals among different age classes, and the genetic makeup of a population
population
historically defined as a group of organisms that can potentially interbreed naturally with each other and produce fertile offspring; current research demonstrates that no single definition can be applied to all organisms
species
5 distinct properties of populations
geographic range (distribution of a population)
abundance
density
change in size
composition
the extent of land or water within which a population lives
distribution of a population
refers to the total number of individuals living within a defined area
abundance
refers to the number of individuals per unit of area
density
refers to increases and decreases in the number of individuals in an area over time
change in size
describes the makeup of the population (sex or age)
composition
the most fundamental unit of ecology
has a membrane, or other covering, across which it exchanges energy and materials with its environment
emphasizes the way in which an individual’s morphology, physiology, and behavior enable it to survive in its environment (as well as its adaptations)
individual
may be an individual, a population or species, a community, an ecosystem, a landscape, or the entire biosphere
entities that have their own internal processes and interact with their surroundings
an ecological system
the scientific study of the interactions among organsims and the environment (biotic and abiotic)
ecology
refers to the typical atmospheric conditions that occur throughout the year, measured over many years
climate
refers to the variation in temperature and precipitation over periods of hours or days
weather
the 600km thick layer of air that surrounds the planet and reflects about 1/3 of the solar radiation emitted toward Earth
atmosphere
the process of solar radiation striking Earth, being converted to infrared radiation, and being absorbed and re-emitted by atmospheric gases
greenhouse effect
what are the most prevalent greenhouse gases
carbon dioxide and water
graphs that plot the average monthly temperature and precipitation of a specific location on Earth
climate diagrams
for every 10 degree Celsius increase in average monthly temperature corresponds to a ________ increase in monthly precipitation
2cm increase
if the temperature growth line goes below the precipitation line in a climate diagram which factor constrains plant growth?
temperature
why are cold regions with high rainfall rare?
because water doesn’t evaprate rapidly at low temperatures and because the atmosphere in cold regions contain very little water vapor
what are the major producers in aquatic ecosystems
algae
how do we categorize biomes in terrestrial ecosystems
by the dominant plant forms that are associated with distinct patterns of seasonoal temperatures and precipitation
geographic regions that contain communities composed of organisms with similar adaptations
biomes
a phenomenon in which two species descended from unrelated ancestors and look similar because they have evolved under similar selective forces
convergent evolution
take into account the coldest temperatures that occur during the winter and follwo the minimum temperature typically reached in locations throughout North America
plant hardiness zones
what are the patterns assessed in plant hardiness zones
latitude
coastlines
elevation
a region with dry conditions found on the leeward side of a mountain range as a result of humid winds from the ocean, causing precipitation on the windward side
rain shadows
what happens when wind blowing inland from the ocean encounters coastal mountains
the mountains force the air upward, which causes cooling, condensation, and precipitation
it then descends the other side of the mountain when the air is warm and dry and creates relatively warm arid environments called rain shadows
factors that can affect regional and local climates
- proximity to coasts
- continental land area
- rain shadows
- plant hardiness zones
- a global pattern of surface- and deep-water currents that flow as a result of variations in temperature and salinity, causing the density of water to change
- responsible for the movement of great masses of water between the ocean basins
thermohaline circulation
how do water vapor emissions come about
large bodies of water, the surface of the land, and the leaves of plants
how do carbon dioxide emissions come about
decomposition, respiration of organisms, and volcanic eruptions
how do methane emissions come about
anaerobic decomposition
how do nitrous oxide emissions come about
wet soils and low-oxygen regions of water bodies
where does ozone come from
ultraviolet radiation breaking apart oxygen molecules in the atmosphere and causing each molecule to combine with another oxygen molecule
the differences in temperature around the globe are a result of
how much solar radiation strikes the surface of Earth at a given location
what are the factors in determining how much solar radiation strikes the surface of Earth at a given location
- the path and angle of the sun
- seasonal heating of earth
- formation of atmospheric currents
- coriolis effect
at the equinoxes, where receives the greatest amount of solar radiation
equator
what factors dictate why the equator receives the greatest amount of solar radiation at the equinoxes
- the distance that sunlight must pass through Earth’s atmosphere
- the angle at which the Sun’s rays hit Earth
- and the reflectivity of Earth’s surface
the fraction of solar energy reflected by an object
albedo
what colored objects reflect a higher precentage of solar energy
light colored objects
what explains the general pattern of declining temperatures as we move from the equator to the poles
unequal heating of the earth
where the sun is at the June solstice
tropic of Cancer
(23.5 degrees N latitude)
where the sun is located at the December solstice
Tropic of Capricorn
(23.5 degrees S latitude)
the circulation patterns of air between the surface of Earth and the atmosphere, and play a major role in the location of tropical rainforests, deserts, and grasslands throughout the world
atmospheric currents
what is the friving force behind atmospheric currents
the upward movement of air
the circulation cells of air between the equator and 30 degrees N or 30 degrees S latitudes
Hadley cells
the area where two Hadley cells converge and cause large amounts of precipitation
intertropical convergence zone (ITCZ)
what does intense sunlight at the solar equator cause
drives Hadley Cells and the ITCZ, causing warmed air to rise and precipitation to be released in the form of rain
true or false:
the latitude of the ITCZ does not move throughout the year
false
at these latitudes, air rises up into the atmsophere and drops moisture
60 degrees N and 60 degrees south
the atmospheric currents that move air between 60 degrees and 90 degrees latitudes
polar cells
- located between Hadley cells and Polar cells from the latitudes of approx 30 degrees to 60 degrees latitude
- areas of atmospheric currents that lack distinct patterns
Ferrel cells
why is the speed of rotation faster at the Equator
because the circumferene of the planet at the equator is much larger than its circumference near the poles
the deflection of an object’s path due to the rotation of Earth is known as
the Coriolis Effect
Hadley cells north of the equator move air along the surface from
north to south
winds that move from the northeast to the southwest
northeast trade winds
winds that move from the southeast to the northwest
southeast trade winds
- wind that moves away from the equator and toward the poles, only to be deflected by the Coriolis effect
- occurs in the latitudes between the Hadley cells and the Polar cells
westerlies
what factors affect ocean currents
- unequal heating
- coriolis effects
- predominant wind directions
- the topography of ocean basins
- differences in salinity
the periodic changes in winds and ocean currents in the South Pacific, causing weather changes throughout much of the world
El Niño-Southern Oscillation (ENSO)
in the atmoshere when the normal difference in air pressure reverses and the equatorial winds weaken and can even reverse direction
Southern Oscillation
what effect does an El Niño year have in North America
it brings cooler, wetter, and often stormy weather to the Southern US and northern Mexico and warm, dry conditions to the northern US and southern Canada
- an event in which equatorial winds blow much stronger to the west and all the effects of the El Niño event are reversed
- regions that become hotter and drier during the El Niño event are reversed
La Niña
- any upward movement of ocean water
- occurs in locations along continents where surface currents move away from the coastline
upwelling
water that is rich in nutrients
deep water
where are strong upwelling zones located
on the western coasts of continents where gyres move surface currents toward the equator and then veer from the continents
tropical waters ________ as they warm
expand
a large water circulation pattern between continents
gyre
gyres move in which direction in the Northern hemisphere
clockwise
typically streams and rivers, characterized by flowing fresh water
lotic systems
a band of terrestrial vegetation influenced by seasonal flooding and elevated water tables
riparian zone
downstream, what happens to water?
the water flows more slowly, becomes warmer, and richer in nutrients
qualities of small streams
- shaded
- nutrient poor
- limits productivity of algae and other photosynthetic organisms
much of the organic content of streams depend on … inputs of organic matter, such as leaves, that come from outside the system
allocthonous
in large rivers, a higher proportion of the organic inputs are …, meaning they are produced from inside the ecosystem by algae and aquatic plants
autochthonous
what happens to rivers as they progress from their source?
they typically become
* wider
* slower-moving
* more heavily laden with nutrients
* more exposed to direct sunlight
* and accumulate sediments that are washed in from the land and carried downstream
downsides of dams to lotic systems
- alter water temperature and rates of sedimentation
- destroy the habitat for fish and other aquatic organismss
- water released downstream from dams often has low concentrations of dissolved oxygen
- changes the natural seasonal cycles of flooding that are necessary for maintaining many kinds of riparian habitats on floodplains
- disrupt the natural movement of aquatic organisms upstream and downstream, fragmenting river systems and isolating populations
an aquatic biome that is smaller than a lake and is characterized by nonflowing fresh water with some area of water that is too deep for pants to rise above the water’s surface
pond
an aquatic biome that is larger than a pond and is characterized by nonflowing freshwater with some area of water that is too deep for plants to rise above the water’s surface
lake
ecological zones of lakes
- littoral zone
- limnetic/pelagic zone
- profundal zone
- benthic zone
the shallow are around the edge of a lake or pond containing rooted vegetation
littoral zone
the open water beyond the littoral zone where the dominant photosynthetic organisms are floating algae or phytoplankton
limnetic/pelagic zone
- doesn’t receive sunlight due to depth
- absence of photosynthesis as well as the presence of bacteria that decompose the detritus at the bottom of the lake, cause this zone to have very low concentrations of oxygen
profundal zone
the sediments at the bottom of lakes and ponds that provide habitats for burrowing animals and microorganisms
benthic zone
surface water in a lake or pond that has a warmer temperature than deeper water
epilimnion
- a middle depth of water that experiences a rapid change in temperature over a relatively short distance in depth
- serves as a barrier to mixing between the epilimnion and the hypolimnion
thermocline
deeper water that has cooler temperatures than the epilimnion
hypolimnion
a shallow narrow channel of fast-flowing fresh water
stream
a wide channel of slow-flowing fresh water
river
small head water streams
1st order streams
1st order + 1st order =
2nd order
2nd order + 1st order =
2nd order
2nd order + 2nd order =
3rd order
water achieves his highest density at one temp
4 degrees Celsius
how do adaptations of aquatic organisms often exploit the density of water
oil droplets, swim bladders, gas filled bulbs
the thickness of a fluid that causes objects to encounter resistance as they move through it
viscosity
what can affect the ability of plants and algae to photosynthesize
declining light intensities with increased water depth
what is necessary for building most compounds found in organisms
large amounts of hydrogen, carbon, and oxygen
the movement of water across a semipermeable membrane
osmosis
the force with which an aqueous solution attracts water by osmosis, expressed in megapascals (MPa) and depends on solute concentration
osmotic potential
what determines the osmotic potential of body fluids
solutes
the mechanism that organisms use to maintain a proper solute balance
osmoregulation
freshwater animals are said to be _…_____ compare to their environment
hyperosmotic
saltwater organisms are said to be … compared to their environment
hyposmotic
how do freshwater fish respond to an influx of water
eliminating the excess water through their urine and add solutes to their bloodstreams using their gills
how do saltwater fish replace a loss of water
saltwater animals drink large amounts of salt water and release only small amounts of water, to counteract the accompanying iinflux of solutes, the excess solutes are actively excreted out of the body usiing the kidneys or gills
what is a challenge of aquatic plants facing salt balance
high osmotic potential of the saltwater environment makes it difficult for the roots to take up water and rid themselves of excess salt
increased concentration of salt in rivers, streams, lakes, and wetlands
freshwater salinization
wha favors the evolution of eusocial behavior and why
being haplodiploid; by providing large indirect fitness effects when workers do not breed and instead help their sisters
when the cost of forgoing reproduction by not leaving the home colony is small, what is no longer required to favor eusocial behavior
a large coefficient of relatedness
why are eusocial species fascinating to ecologists
because most individuals dont mature sexually or reproduce, instead they specialize at tasks that include defending or foraginf for the group or taking care of the subsequent offspring of their parents
consists of individuals within a social group that share a specialized form of behavior
caste
what has the concept of kin selection given ecologists a better understanding of
the evolutionary reasons underlying a wide variety of altruistic and selfish behaviors in animals
when selfish interactions provide direct fitness to the donor, altruistic interactions provide…
indirect fitness benefits to the donor, weighted by the coefficient of relatedness between the donor and the recipient
if the inclusive fitness of altruistic behaviors exceeds the inclusive fitness of selfish behaviors, then…
altruism will be favored by natural selection
genes for altruistic behavior will be favored in a population when…
the fitness benefit to the recipient (B) times the recipient’s coefficient of relatedness to the donor (r) is greater than the direct fitness cost to the donor (C)
B * r > C
for altruism to evolve,
the cost-benefit ratio must be less than the coefficient of relatedness between the donor and recipient
C / B < r
the fitness benefit gained by a recipient relative (B) multiplied by the coefficient of relatedness between the donor and the recipient relative (r)
indirect fitness benefit
indirect fitness benefit = B x r
direct fitness is favored by
direct selection
indirect fitness through relatives is favored by
indirect selection/kin selection
the probability that copies of a particular gene are shared by relatives
coefficient of relatedness
the coefficient of relatedness of a focal individual and its parents would be
0.5
the coefficient of relatedness between a focal individual and its siblings is
0.5
the coefficient of relatedness of a focal individual and its cousin would be
0.125
why is altruism an interesting evolutionary behavior
because it doesn’t lead to an increase in direct fitness
the fitness that an individual gains by passing on copies of its genes to its offspring
direct fitness
increases the fitness of the recipient but decreases the fitness of the donor
altruism
occurs when a social interaction gives both the donor and recipient lower fitness
spitefulness
- when the donor experiences fitness and the recipient experiences decreased fitness
- a common interaction between two conspecifics that compete for a resource such as food
- the winner of the competition receives a fitness benefit, while the loser experiences a fitness loss
selfishness
when the donor and the recipient both experience increased fitness from the interaction
cooperation
social rankings among individuals in a group, typically determined by through fighting or other contests of strength or skill
dominance hierarchies
any area defended by one or more individuals against the intrusion of others; typically valuable because they contain resources; can be transient or permanent
territory
benefits to living in groups
- increased rate of survival
- rate of feeding
- success in finding mates
the reduced, or diluted probability of predation to a single animal when it is in a group
dilution effect
the location of the aggregation to put on a display to distract the opposite sex
lek
costs of living in groups
- predation
- parasitism
- competition
what size group has the lowest stress level and why
medium-size groups because they travel less than either small or large groups and experience lower competition
when carbon dioxide dissolves in water, most of the molecules combine with water and are quickly converted to
carbonic acid (H2CO3)
when a system deviates from its desired state or set point, internal response mechanisms act to restore that desired state
negative feedback
plants possessing the C3 photosynthetic pathway are better adapted to what type of conditions
cool and wet
plants possessing the C4 and CAM photosynthetic pathways are better adapted to what type of conditions
warm and arid
- using mesophyll and bundle sheath cells, these plants separate the steps in time
- open stomata for gas exchange during the cool night (transpiration minimal), conduct photosynthesis during the hot day
- assimilate CO2 into OAA, which is then converted to malic acid and stored at high concentrations in vacuoles
- regeneration of PEP from pyruvate following release of CO2 regulated
- results in extremely high water-use efficiencies and enables plants to occur in water-limited conditions and happens at a relatively low rate
CAM photosynthesis
closing of stomata as a result of hot and dry conditions results in
- decrease of CO2
- increase of O2
- increase in photorespiration
- first step of this pathway joins CO2 with phosphoenol pyruvate (PEP) to produce oxaloacetic acid (OAA)
- catalyzed by PEP carboxylase, which has a higher affinity for CO2 than rubisco
- calvin cycle takes place in chloroplasts of bundle sheaths
- allows stomata to remain partially or completely closed for longer periods of time, which reduces water loss
CO2 + PEP –> OAA
C4 photosynthetic pathway
disadvantages of C4 photosynthesis
- less leaf tissue devoted to photosynthesis
- some of the energy produced by the light reactions is used in the initial C4 carbon assimilation step
where are C4 plants most prevalent
tropical and subtropical grasslands
benefit of utilizing PEP carboxylase for photosynthesis
has a higher affinity for CO2, so it can bind CO2 at a lower concentration in the cell
depending on the pH of the water, carbonic acid molecules can release hydrogen ions to form either
bicarbonate ions or carbonate ions
readily dissolve in water, most common form of inorganic carbon in aquatic habitats
bicarbonate ion
dissolved CO2 and bicarbonate ions are in
chemical equilibrium
a region of unstirred air or water that surrounds the surface of an object
boundary layer
what is an important adaptation that allows aquatic animals to deal with a limited amount of oxgen
the direction of blood flow in the gills, which is used to extract oxygen from the water
two fluids moving in the same direction on either side of a barier and heat or material are exchanged
concurrent circulation
two fluids move in opposite directions on either side of a barrier and heat or materials are exchanged
countercurrent circulation
what happens when blood and water flow in opposite directions
the concentration of oxygen in the water exceeds the concentration in the blood throughout most of the region of contact
what type of blood flow in animal gills allows much more oxygen to be extracted from the water and moved to the gills
countercurrent blood flow/circulation
an environment completely devoid of oxygen
anaerobic or anoxic environment
the layer of chemically and biologically altered material that overlies bedrock or other unaltered material at Earth’s surface
soil
what is the makeup of soil?
- materials derived from parent material
- modified minerals formed within the soil
- organic material contributed by plants, air, and water within the soil
- organic material contributed by plants, air, and water within the pores of the soil
- living roots of the plants
- microorganisms
- larger worms and anthropods that make the soil their home
known as the bedrock that underlies soil and plays a major role in determining the type of soil that will form above it
parent material
categorized by the components and process that occur at each level of soil
horizons
what are the soil characteristics determined by
- climate
- parent material
- vegetation
- local topography
- age
the physical and chemical alteration of rock material near the earht’s surface, occurs whenever surface water penetrates parent material
weathering
- a measure of the potential energy of the water and indicates its tendency to move from one area to another
- affects the movement of water in the soil from one location to another and depends on several factors
water potential
factors that affect water potential
- gravity
- pressure
- osmotic potential
- matrix potential
the potential energy generated by the attractive forces between water molecules and the matrix of soil particles
matrix potential
the lowest water potential at which most plants can obtain water from the soil
wilting point
the water molecules closest to the surfaces of soil particles adhere the most (weakly/strongly)
strongly
the maximum water held by soil particles against the force fo gravity or the maximum amount of water available to plants of the soil
field capacity
the amount of water in soil and its availability to plants depend on
- the physical structure of the soil
- the more surface area or volume of the soil it has
soils with a high proportion of what particles hold more water on their surfaces than soils with a high proportion of silt particles
clay
soils with a high proportion of what particles hold more water on their surfaces than soils with a high proportion of sand particles because they tend to dry out since water quickly drains away
silt
as we move away from sand to silt to clay, avg particle size declines and what happens as a result
there is an increase in both field capacity and wilting point
soils that are high in what particles are poor soils for growing many plants including crops that humans rely on for food
sand or clay
the best soils for growing plants are those containing
a mixture of silt, clay, and sand, such as loam
- catalyzed by RuBP carboxylase-oxidase (rubisco), has a low affinity for CO2
- creates 2 molecules of glyceraldehyde 3-phosphate (G3P)
- CO2 is initially assimilated into G3P
- vast majority of plants on earth use this photosynthetic pathway
- carbon assimilation using rubisco is inefficient at low concentrationsof CO2, high levels of rubisco needed
C3 photosynthesis
- leads to high O2 concentrations and low CO2 concentrations in the leaves
- caused in part by closed stomata
- consumes energy and O2, which produces CO2
2 G3P –> RuBP + CO2
photorespiration
under what conditions does rubisco preferentially bind to O2 rather than CO2
- high temps
- high O2 concentration
- low CO2 concentration
- light reactions that depend on the light energy from the Sun and include a series of events from the absorption of light to the production of high energy compounds and CO2
- the Calvin Cycle in which these high energy compounds ATP and NADPH which are used by the cell to convert these compounds to convert CO2 into glucose
6 CO2 + 6 H2O + photons –> C6H12O6 + 6 O2
photosynthesis
if a root cell has a higher solute concentration than the soil water what happens
osmotic forces can draw the water into the root
prevent large solute molecules from leaving the plant’s root
semipermeable membranes
actively transport ions and small molecules against a concentration gradient into the root cells
cell membrane
- small opening on the surface of leaves that are points of entry for CO2 and points of exit for water vapor and oxygen
- collapsing guard cells closes these
stomata
the movement of water through xylem cells depends on
the cohesion of water molecules
what happens to plants growing in places with strong matrix potentials
increase concentrations of amino acids, carbohydrates, or organic acids in their root cells to create higher osmotic forces that help move water into the roots (comes at a high metabolic price)
the increased salt concentration of the soil with repeated irrigation events
soil salinization
the evaporated water that moves out of the leaves and into the air
transpiration
the water potential from transpiration creates
a continuous gradient from leaf surfaces in contact with the atmosphere down to the surfaces of root hairs in contact with soil water
the mechanism of water due to both water cohesion and waer tension
cohesion-tension theory
more plant diversity =
more animal diversity
depend on flow, depth, temperature, salinity, and O2/oxygen
aquatic biomes
the bed of a stream or river through which the majority of water flows; the deepest and most navigable part of a channel
main channel
two adaptations plant species display to retain and obtain water
- root depth (shallow, quick; deeper, less and slower)
- leaf characteristics (waxy coatings prevent evapotranspiration and small hairs can provide amounts of shade)
- ability to regulate osmotic potential
if you were to find a new plant species in an arid environment with spatial separation of photosynthesis and respiration processes what would you classify it as
C4
C4 plants are found in arid/dry environments as well as CAM plants, but C4 plants specifically separate their light and dark reactions spatially. CAM plants separate theirs temporally
what adaptation would be needed for controlling the depth in the water at which the organism wants to stay at
swim bladder
what adaptation would be needed to consume oxygen very efficiently
slow metabolism
what adaptation would be suited for extracting oxygen from gills and swim bladders very efficiently
extra hemoglobin
what adaptation would be best suited for forcing water to travel from soil into roots
osmotic potential
what adaptation would be best suited for maximizing oxygen absorption from water into blood
countercurrent circulation
what adaptation would be best suited for accessing the water that stays in higher levels of the soil
shallow root depth
how does selection act on behavior
- selection acts on phenotypes, not genotypes and behavioral adaptations are phenotypic traits just like color or morphology
- these traits are advantageous and heritable as well
plants living in dry climates with dramatically different conditions during the day vs at night tend to exhibit … isolation between photosynthetic reactions whereas plants living in more consistently dry and hot conditions tend to exhibit … isolation between photosynthetic reactions
temporal; spatial
why does countercurrent circulation work
- Countercirculation ensures that there is always a gradient for the oxygen to travel from the water to the blood
- If the low oxygenated blood encounters the water first, the oxygen from the water will be immediately depleted, which would destroy the oxygen gradient
- If the oxygen rich blood encounters the water first, however, the water’s oxygen will not be quickly depleted, meaning that there will still be lots left for the gradient to be maintained for the oxygen poor blood
… moves water throughout the plant, whereas … pulls water into the plant
xylem, transpiration
when nurients/minerals leach down through layers
eluviation
when nutrients/materials build up in a layer due to eluviation
illuviation
used to determine stream quality
EPT
stoneflies (plecoptera)
caddisflies (trichoptera
Mayflies (Ephemeropter)
Stoneflies (Plecoptera)
Caddisflies (Trichoptera)
- where lotic and terrestrial systems meet
- good for higher vegetative diversity
- important for stream/river health
riparian zone
allocthonous zones are typially what type of streams
lower order
autochtonous zones are typically what types of streams
higher order
what biome is pittsburgh located within? what are some characteristics of that biome
Temperate seasonal forest; high levels of precipitation and humidity, well-defined seasons, variety of deciduous trees which lose their leaves in the fall / winter seasons, etc.
A new island formed by volcanic action may eventually become populated with biotic communities as a result of
the process of ecological succession
Which zone in ecology is associated with organisms such as mayflies, stoneflies, and caddisflies, and is often used as an indicator of water quality?
benthic zone
What is the ITCZ (Intertropical Convergence Zone) and where would it be found?
The intertropical convergence zone is located along the equator where the north and south trade winds converge. This area receives large amounts of rain due to the solar heating and large amounts of evaporation
a process that causes water to mix because the changing seasons and fluctuating temperatures change the water temperature
turnover
- Turnover occurs in temperate climates that have rotating seasons
- The density of water is dependent on temperature and these temperature changes (specifically in the spring and fall) cause vertical mixing as the surface temperature drops or rises
- Spring turnover brings nutrients from sediments on the bottom to the surface and oxygen from the surface to the depths
- Fall turnover brings oxygen to deep waters and nutrients to the surface
Marginalized communities experience effects of climate change more and receive help less
environmental injustice
long-term heating of Earth’s surface due to anthropogenic inputs of greenhouse gases
global warming
’
the efficiency of an organism’s water use is best determine by
the overall size of the kidneys relative to the size of the mammal’s body
larger kidney sizes are found in places with
less precipitation
the ultimate source of heat at the surface of the Earth
sunlight
the emission of electromagnetic energy by a surface
radiation
the transfer of heat between objects that are in contact with one another, with heat moving from the warmer object to the cooler object
conduction
the rate at which heat moves by conduction between an organism and its surroundings depends on what three factors
- its surface area
- its resistance to heat transfer
- its temperature difference between the organism and its surroundings
the transfer of heat by the movement of liquids and gases
convection
plant adaptations to cold temperatures
- moving water out of cells, forcing ice to only occur between cells to not cause damage
- growing low and close to the sun-warmed ground allows plants to experience warmer temperatures
occurs when blood vessels can be shut off at precapillary sphincters so that less of the animals warm blood flows out to the extremities, where heat would be lost to the cold environment and is redirected into the veins before it reaches them
blood shunting
adaptations of the animal circulatory system
- blood shunting
- countercurrent circulation
- maintain a higher body temperature to occupy environments that ectotherms aren’t able to occupy
- gain heat from solar radiation, conduction, convection, or metabolic heat
endotherms
the rate of metabolism required to maintain a particular body temperature (increases/decreases) in direct proportion to the difference between the temperature of the body and the temperature of the environment
increases
the greater the difference between an animal’s body temperature and the outside temperature,
the greater the heat loss
adjust their heat balance behaviorally by moving into or out of shade, by changing their orientation to the Sun, or by adjusting their contact with warm substrates (ex: basking)
ectotherms
true or false:
because large organisms have a low ratio surface area to volume, larger individuals transfer heat across their surfaces more rapidly than smaller individuals
false
less rapidly
organisms that thermoregulate by maintaining a constant body temperature
homeotherms
organisms that thermoregulate via maintaining variable body temperatures
heterotherms and poikilotherms
having a thicker boundary layer will do what for convection of heat of an animal
will tend to slow heat transfer between the air surrounding an organism and the air moving past an organism
the transformation of a liquid to a gas with the input of heat energy
evaporation
what is a substantial cost of evaporation
water loss
all endotherms are
homeotherms
how do animals regulate temperature through behavioral mechanisms
- basking, gaping, shivering
how do animals regulate temperature through mechanical mechanisms
countercurrent circulation
how do animals regulate temperature through physiological mechanisms
- blood shunting
- sweating
- hibernation
- torpor
how do animals actively maintain water balance
- stay near water
- tolerate water loss
- resist water loss
