Exam Two: Learning Objectives Flashcards
Water is a __ solvent
universal
Water content of organisms must stay between __ and __ of body mass
60, 90
What is the medium in which all biochemical reactions necessary for life occur?
water
Water moves __ concentration gradients from __ to __ water pressure
DOWN
higher; lower
Water moves down a concentration gradient between terrestrial organisms and air via __ __ __
vapor pressure deficit
Water moves down a concentration gradient between aquatic organisms and the water they are in via __ __ __
osmotic pressure gradients
Water moves down a concentration gradient along the soil-plant-atmosphere continuum via __ __
water potential
Water will flow from an __ to __ via evaporative water loss
organism; air
Define vapor pressure deficit?
difference in the amount of water vapor air could hold (given its temperature) and the amount it is actually holding
Evaporative water loss is determine in party by an organism’s __ __ adaptations
water-retaining
Air is always __ than the inside of an organism, and water always flows __ a concentration gradient, so water will flow from an __ to the __ via __ __ __
drier; down
organism; air
evaporative water loss
Describe the VPD in warm and cold air
warm air can potentially hold lots of water as vapor,
cold air cannot hold a lot of water
VPD will be high if the air is _ and __ but low if air is __ or humidity is __
warm; dyr
cool, high
Why is the VPD low if humidity is high?
humid air already has lots of moisture and cannot hold much more
Evaporative water loss is influenced by _ __ __
vapor pressure deficit
Discuss the consequences of vapor pressure deficit if VPD is high (warm, dry air)
water will evaporate from terrestrial organisms
water loss (bad)
evaporative cooling (good)
Discuss the consequences if VPD is low (cool, humid air)
less water will evaporate from terrestrial organisms
minimal water loss (good)
little possibility for evaporative cooling (bad)
Water moves between aquatic organisms and the water they are in via __ __ __
osmotic pressure gradients
Water and solutes move __ concentration gradients
down
How does water transport from the soil through the plant to the atmosphere takes place in?
the soil-plant-atmosphere continuum
Soil, plant, and atmosphere are interconnected by?
a continuous film of liquid water
Water flows to a more __ water potential
negative
Define water potential
the gradient from which water moves from the soil through the plant to the atmosphere
What factors determine water potential in a plant?
solutes, matric, and pressure
What factors determine water potential in a soil?
matric
A free standing body of pure water has a water potential of _, while in nature, water potentials have a __ (__) value
zero
lower; negative
What are three factors that reduce water potential in soil-plant systems (make water potential more negative)
solutes
matric forces
negative pressure
Discuss the water potential in solutes
water is drawn toward areas with a lot of solutes
Discuss the water potential in matric forces
thin films of water are attracted to (hard to pull off of) the surface of soil particles, cells, or walls of narrow vessels in plants
__ films are held more tightly, and __ soil particles provide more surfaces for water films to adhere to
thinner; finer
Discuss the water potential of negative pressure
water is drawn ttowards areas of low pressure (water evaportation into dry air imposes a ‘sucking’ action on wetter plant tissues)
How do plants get water through roots from soil?
water potential of roots is lower (more negative) than water potential of soil
Terrestrial animals gain water through __ and __
absorption; consumption(eating and drinking)
What are the two forms of food water?
moisture content of food and metabolic water
metabolic water generated during __ __ - water is produced by the __ as it breaks down __ __
cellular respiration
consumer
organic matter
Individuals who originated from the __ location showed the lowest evaporative water loss
dry
Discuss evaporative water loss and the trade off of skin adaptations
skin thickness and composition can be adaptations to regulate evaporative water loss and thus water balance
there’s a tradeoff with ability to evaporatively cool and exchange gases
How do desert scorpions manage heat and water budgets?
burrowing during the day reduces heat gain and reduces evaporative water loss
low metabolism and cuticle covering
How do desert cicadas regulate heat and water budgets?
dump lots of body heat through evaporation
adaptation for high water gain through drinking, pierce mesquite trees and drink plant fluids
What are two ways plants compensate for variation in water availability?
drop leaves and increase gain with deeper roots
Dropping leaves in response to water stress can be an __ way to lose water. Instead they shut off __
expensive; stomate
In response to soil drying, some plants send a hormonal __ to the guard cells that closes the __ to prevent __ loss
signal
stomata
water
Define stomata
gas-exchange pores on the underside of leaves
Adaptations revealed in __ __ responses to environmental change
short-term
The ability to acclimatize is an _
adaptation
In marine environments, water tends to diffuse __ of organisms, via __ and __
out
concentrated urine
drinking water
In freshwater environments, water tends to move __ to the organisms via methods of?
into
large volumes of dilute water
What are two adaptations to maintain osmotic balance in water that is saltier than inside the organism ?
drink water and dump solutes
Isosmotic organisms have internal __ and __ concentrations that match those of their environment, but must selectively control __ of specific solutes
water; salt
exchhange
Define trophic
feeding and nutrition
What is the purpose of feeding?
to grow, heal, move, reproduce, achieve homeostasis, and maintain cellular order
What are the three trophic categories
photosynthetic autotrophs
chemosynthetic autotrophs
hetertrophs
Discuss the carbon and energy source of photosynthetic autotrophs
CO2
sunlight
What organisms are photoautotrophs ?
organisms with light-harvesting pigments (usually chlorphyll)
vascular plants
microalgae
phytoplankton
bacteria
eukaryotic algae
Where does photosynthesis occur?
chloroplasts
Define chloroplasts
organelles in plant cells that have sunlight-capturing pigments (chlorophyll a)
Cyanobacteria are photosynthetic __, the cell is essentially a __
prokaryotes; chloroplast
What are the three components of photosynthesis?
light reactions, carbon fixation, and biosynthesis
Discuss the light reaction component of photosynthesis
absorb light; transfer energy to ATP and electrongs
Discuss the carbon fixation component of photosynthesis
C from CO2 is captured
Discuss the biosynthesis component of photosynthesis
organic biomolecules are synthesized
What is C3 photosynthesis?
found in most plants and algae
Discuss the synthesis of C3 photosynthesis
C from CO2 combines with a 5-carbon compound called ribulose bisphosphate (RuBP)
Rubisco catalyzes the combination of RuBP and C
creating two, three carbon molecules which are then used to make glucose
Water loss is a __ on C3 photosynthesis
limitation
Water loss = closing of __, plant can’t take in __, with stomata closed, __ combines with O2 in __ instead of with __. Reduces the __ capture and thus reduces the __ of organic C
stomata
CO2
RuBP
photorespiration
CO2
synthesis
What are the three photosynthetic pathways?
C3, C4, and CAM
What is the purpose of C4 and CAM pathways?
perform carbon fixation at a different time or location when and where light reactions and biosynthesis can occur
CAM and C4 are __ of C3
elaborations
CAM and C4 pathways initially fix C with __ instead of Rubisco, because it is better at catching __
PEP C
CO2
How do CAM and C4 pathways enable photosynthesis without light?
C fixation requires open stomata, but light reactions and biosynthesis do not
CAM: PEPC catches __ during the night, then delivers it to __ during the day, at which point the normal __ pathways occurs
CO2
Rubisco
C3
C4: PEPC catches __ in the __ cells, then delivers it to __ in the bundle sheath cells, which reside __ in the leaf tissue and then the normal __ pathway occurs
CO2
mesophyll
deeper
C3
What is the advantage of C4 and CAM pathways?
Plants can open stomata less and still get needed CO2, resulting in less photorespiration and less water loss
PEP C just __ the CO2-derived C __
holds; temporarily
CAM performs C fixation at a different __ and C4 performs C fixation at a different __
time
location
CAM; C fixation at night when __ can safely open with low __ loss
stomata
H2O
C4 plants perform better in high __ and __, and low __ availability
light; temperature
water
C4 plants includes half the __ and found prominently in __ and __ grasses, contributes to 20% of __ __ __ and includes many species of commercial importance (corn)
grasses
tropical; subtropical
terrestrial plant production
Temperature predicts balance of __ and __ plants
C4, C3
In locations that are warmer, a __ percentage of grass and shrub species are __
higher; C4
__ species dominate in grasslands and shrublands of __ regions
C3
cooler
CAM plants have the best __ __ _
water use efficency
CAM plants are found in __ and __-__ environments, including many families including __, __, __, and __
arid; semi-arid
succulents, cactuses, bromeliads, orchids
CAM plants have slower __ but great __-__ __
photosynthesis; water-use efficency
Describe water use efficency
use (and loss) very little water per gram of biomass added; even better than C4
What is the carbon and energy source of chemosynthetic autotrophs
CO2
reduced inorganic compounds
Chemosynthetic autotrophy: reduced __ provide _ for eTC, sets up __ __, which leads to __ and __ of organic carbon, needs a terminal electron __ (can be _)
molecules, e-
proton gradient
ATP synthesis, biosynthesis
acceptor, O2
Compare and contrast chemo and photo autotrophs?
both synthesize ATP and fix C, but get e from reduced inorganic molecule rather than sunlight splitting water
What are two examples of reduced molecules in chemosynthetic autotrophy?
H2S and NH4+
What is an important example of chemosynthetic autotrophy
nitrifying bacteria play a very important role in the nitrogen cycle
What is the carbon and energy source for heterotrophs?
organic C and organic C
What are the three major categories of heterotrophs?
herbivores, carnivores, and detritivores
What are three challenges of herbivores (heterotrophs)?
chemical defenses, stoichiometric constraints, and physical defenses
Define a nutrient
chemical element required for the development, maintenance, and reproduction of an organism
What is an example of a nutrient?
Nitrogen
What are the five primary nutrient requirements?
C, O, H, N, and P
Why are nutrients important?
to maintain chemical composition, i.e. obtain nutrients in the proper ratios
What is a stoichiometric constraint?
difficulty getting food with proper nutrient ratios
What is a challenge detritivores face?
stoichiometric constraints
What is the diet of detritivores?
dead organic material (detritus)
Detritivores: __ and __ do most decomposition, also includes lots of __ __ and __ of many sizes, known as the __
fungi, bacteria
eukaryotic protozoans, animals
recycles
Carnivores have a good __ match
stoichiometric
high food __ is balanced by low __ availability
quality; prey
Why is most prey unfavorable to consume?
hard to find, well defended
Energy to catch prey might be _ than the energy value of the prey
greater
There is energy __ up trophic levels
loss
A carnivores potential diet items are __ similar, which permits diet __ and __
nutritionally
flexibility; variability
What is the equation of profitability?
value of food item/ energy and time cost of finding, catching, subduing, eating, and digesting food item
Optimal foraging: the most common food option is not always the most __ favorable
energetically
Net energy gain by bluegill sunfish is maximized by?
selecting larger prey items, even though they are rare and require more energy to hunt
Carnivores are often _–__ predators, hence __ animals feed on __ prey and smaller animals feed on __ prey
size-selective
larger; larger
smaller
While animals may chose prey of a certain size, or with the greatest net energetic return, plants will invest in either __ or __ depending on which resource is most __
roots (below ground)
shoots (above ground)
limiting
More investment of roots when below ground (soil) resources are __, i.e. __ root growth with __ supplies of soil nitrogen or soil water
limiting
more
lower
The rate at which organism take in energy is limited either by _- or __
the environment, internal constraints
Why does the environment limit energy?
environment does not provide sufficient energy
How do internal constraints limit energy?
lots of energy is available, but organism is incapable of taking it all in
When resources are __, the rate of resource use by organisms is limited by how __ they can eat or absorb the resource
abundant, quickly
When resources are __, the rate of acquisition by organisms is limited by __ __
scarce
resource supply
What are two examples of internal constraints ?
photosynthetic rate and photon flux density
feeding rate and food availability
What do photosynthetic response curves show?
How the rate at which a plant takes in energy (photosynthetic rate) responds to an increase in the rate at which energy is supplied
photon flux density is equal to?
rate at which light particles hit the plant
Where are external constrains on energy intake shown?
over the rising part of the curve at low levels of light
What does the curve on a photosynthetic rate show?
the rate at which a plant acquires energy (Y axis) is constrained by the rate at which the environment supplies energy to the organisms (x axis)
external constraints on energy intake
Where are internal constraints represented on an energy intake curve?
over the flat part of the curve at high levels of light supply
What does the internal constraints curve represent on energy intake?
the rate at which a plant acquires energy (y axis) via photosynthesis is constrained by its own availability to use the plentiful supply of light
T/F: Plant species show different photosynthetic response curves
true
What do the differences in photosynthetic response curves represent?
how adaptation to one set of conditions has costs in other conditions
shade species that can photosynthesize well in __ light cannot respond to __ light
low; abundant
Sun species that can take advantage of __ light levels, don’t do well in the __
high; shade
Sun species that synthesize lots of __ to harvest abundant light, but protein synthesis requires a lot of __; costly if incoming light is __
protein
energy
insufficient
Energy intake by animals also shows __ and __ constraints, via __ __ curves
external, internal
functional response
Heterotrophs: different -vores use different, __ __, each with some __(stoichiometric mismatches, well-defended prey)
food types
constraint
Sexual reproduction involves the ?
input of genetic material from two individuals
Why are social relations important?
they directly influence an organisms reproductive success - its fitness, or contribution of genetic material to future generations
Define sexual selection
selection for traits that improve mating success and thus reproduction rate
Distinguish the difference between inter and intra selection
inter - competition among mates, through fighting
intra - selection by females, peacock feathers
Why do antlers develop due to intersexual selection?
males have to fight to mate, bigger antlers equals more mating
male guppy coloration shows an example of selection for a trait through __ __ (__) and against that same trait through predation
mate choice; interselection
Where will you find mostly dull-colored guppies?
areas of high predation
Discuss the counteracting forms of selection between male choice and predation in crickets
interselection
females of parasitoid fly find male crickets by listening for chirping, females select males by their chirps
Mate choice by females may be based on male ability to provide __
resources
Do large or small male scorpion flies have a higher mating success?
large
Male scorpionflies provide a resource, and therefore have a high __ success, but this requires a lot of __
mating
energy
Mating in plants is ?
nonrandom
What evidence is there that plants mate non-randomly?
multiple pollen donors provides mating options for maternal plant
Discuss the good genes hypothesis
ornamental traits may signal that a male is good at obtaining resources
ornamental traits may signify that a male has other more functionally ‘useful’ traits
mating with an ornamental male increases chances that sons and daughters will have those useful traits
Discuss the sexy sons hypothesis
ornamental traits are nothing more than ornamental; they do not signal that a male has other useful traits
but females are attracted to these ornamental traits
mating with an ornamental male increases the chances that sons will be ornamented and thus attract mates of their own
Define fitness
genetic contribution to future generations
Kin selection will favor __, which can increase one’s __ __ (all offspring with whom one shares genes)
altruism, inclusive fitness
Altruism is associated with __
sociality, aka group living
Sociality is often characterized by individuals that don’t __
reproduce
In some species, individuals live in __ groups, referred to as __
cooperative; sociality
If an animal has __ alleles, its likely its nieces do to, helping raise its nieces advances its __ alleles on to __ generations (__)
helper; helper
future
altruism
What are two benefits to helpers in cooperative breeding arrangements?
inclusive fitness
improve own chance of breeding (gain experience, delay reproduction)
What is an example of social organisms?
Bees, woodhoopoes, and monkeys
Define philopatric
stay near home
How are woodhoopoes an example of sociality?
philopatric, helping behavior by siblings and half-siblings, inheritance of quality habitat, delayed reproduction (females), higher fitness
__ quality territory: lots of sturdy __ __ in trees, favorable years = years when the dry season is actually __, __ of food
high; roosting cavities
dry; lots
Eusociality is a highly __ form of sociality with __ living groups, __ care for young, and very high __ among individuals. There is a division of individuals in __
specialized
multigeneration
cooperative
relatedness
castes
Discuss the castes in eusocialized groups
groups of physically distinctive individuals that performs specialized tasks, often related to body size
sterile, non-reproductive, and reproductive groups
Adaptations that affect the fitness of individuals will influence __ and __
range, dynamics
A species cannot survive in locations where the value of an __ variable falls outside its __ range of __
environmental, physiological, tolerance
Define the principle of allocation
each individual organism has a finite (limited) quantity of resources that it can use for all necessary life processes,
Individual organisms cannot __ and __ under environmental conditions where the cots of basic maintenance are too __ or conditions are __
grow; reproduce
high; lethal
A populations geographical distribution (__) will be limited to areas where sufficient __ can be __ to __ and __
range
energy
allocated
growth; reproduction
What are three examples of environment limiting range?
coastal ghost forests, american alligator, and eastern phoebe
What is a fundamental niche?
acceptable suite of physical conditions, in the absence of interactions with other species
What is a realized niche?
suite of environmental conditions, including physical conditions and biotic interactions, in which a species can survive, grow, and reproduce
Chthamalus adults do not persist in mid-intertidal zones because?
they can’t compete with Balanus
Biotic and abiotic factors combine to shape __ __ and fine-scale __
realized niche; distribution
What impacted bettong range collapse?
biotic interactions - predation and competition for resources
Hawaii akepa bird is limited to the tops of mountains by __, which is limited by __
malaria
temperature
Discuss the impact of climate change on Hawaii akepa birds
With temperatures rising, birds may be confined to a higher elevation because malaria can now travel further up the mountain
Most individuals in a population are found in just a __ spots, cluster in areas where environment meets __ __ which describes _- __
few
niche requirements
patchy distribution
What are two examples of patchy distribution?
trees and red-eyed vireos
Why might young plants have a clumped distribution?
there are a limited number of safe locations, seeds don’t disperse far, and asexual reproduction
Regular distributions tend to result from __ and __, where organisms or colonies are…
aggression; competition
as far away from one another as possible
The environment limits __
distribution
Populations distribution is limited to __ __ where environment matches __
geographic locations
niche
Population range and patchy distributions respond to __ and __
environment
patchy distribution
Define dispersal
the movement of individuals and propagules
Dispersal can __ the size of a populations range when individuals move into __ areas not currently occupied by the __
increase; new; occupied
Dispersal can __ the size of a populations range when individuals move __ of a portion of the existing range
decrease; out
Dispersal can shift the location of a range when
a population shifts its spatial distribution
Discuss the dispersion of a collared dove
started in Turkey and spread to all of Europe in 90 years due to dispersal of young birds (adults are sedentary)
Discuss the dispersal of maple trees
range expanded as climate changed and areas become more suitable to maple, climate changed to match the maple’s niche
Describe the dispersal of the honeybee
range expansion occurred rapidly after a dispersal barrier (Atlantic ocean) was overcome, Americas’ environment was already suitable, matched the bee’s niche
What is the primary difference in dispersal patterns between bees and maple trees and doves?
bees - dispersal barrier
doves and maple trees - environmental limitation
Climate change is shifting ranges approx _ m __ a decade
6; upward
Define numerical response
change in consumer density in response to change in resource supply
What are the two mechanisms of numerical responses?
1 consumers are attracted to food, e.g. predators disperse to areas of abundant prey (instantaneous)
2 consumers produce more offspring. More food = more reproduction and offspring survival (lagged response, e.g. more food this year = more babies next year)
Density of predatory birds rise and falls in nearly perfect with with abundance of __ (-), suggesting more voles = more __, representing a mechanism of __ __, voles follow __, () and birds produce more __(_)
prey; voles
reproduction
numerical response
food (#1)
offspring (#2)
At a given location, bear and seagull densities __ as these predators come and go
fluctuate
Gulls and bears disperse from stream to stream, showing up at each stream when __ arrives and leaving when __ are depleted
food (salmon)
salmon
The movement of __ is perhaps the most distinctive feature of streams
distinctive
Downstream flow has a strong __ on dispersal of stream __
influence; organisms
Define drift
downstream dispersal which can be active or passive
Define colonization cycle
upstream dispersal that balances drift
Discuss the lifecycle of mayflies
live in water for up to a year as juveniles, emerge as an adult (aerial) fly upstream, disperse through flight to reproduce and lay eggs in water
Population distributions are _- or __ and __ is important for population dynamics
patchy, discontinuous
dispersal
Define a metapopulation
network of semi-isolated local populations that are linked by periodic exchange of individuals
Butterflies were likely to leave small local populations (__ __) for large ones (__ __)
source populations
sink populations
Background matrix of metapopulations affects __ of dispersal routes between patches
viability
Define population dynamics
refers to changes in the distribution and density of a population
What happens if metapopulation connections are severed?
loss of source-sink dynamics, depleted patches cannot get replacement individuals
Smaller populations have __ genetic diversity
less
Which two aspects of population density add individuals?
birth and immigration
Which two aspects of population density remove individuals?
death and emigration
What does a survivorship curve represent?
a schedule of mortality and survivorship, i.e. when, or at what ages, organisms die
In a population age distribution graph __ is on the y axis and __ is on the x axis
number of survivors, age
A life table is a tabular version of a __ __
survivorship curve
What’s the difference between a static and cohort life table?
static - age dist. at a point in time
cohort - tracks a single cohort as it ages
What do age distributions show?
abundance of each age class in a population
Define recruitment
adding new members to the population through birth and survival of young
How can recruitment be shown on age distributions?
shown one year AFTER event
What is a type one survivorship curve?
low infant and juvenile mortality rate, most die elderly (humans and dall sheep)
graph is upside down exponential
What is a type II suviorship curve?
graph is linear
all ages have same mortality rates (birds and mud turtle)
What is a type III survivorship curve?
juvenile mortality rate is the highest, and lowest is adult (plants)
curve is exponential
What does Ro stand for?
net reproductive rate
average number of lifetime offspring per individual
What does T stand for?
generation time,
average age of reproduction
What does r stand for?
per capita rate of increase
interpreted as birthrate minus death rate
What does a positive r value mean? negative?
positive means population is growing
negative means population is declining
What does rmax represent?
intrinsic rate of increase
r when conditions are ideal
Populations are limited by __ __ and __ __
physical environment
biotic interactions
Population densities change via __, __, __
dispersal, birth and death
What are the five limited conditions populations can grow exponentially for a limited time under certain conditions?
favorable environments, low population densities, abudnant resources, and few natural enemies
conditions are most likely with invading and recovering populations
What are two examples of exponential growth?
scots pine after post-glacial colonization
whooping crane after protection
Populations cannot continue to grow exponentially because?
eventually some factor limits growth,
the environment (biotic and abiotic) limits population growth by changing birth and death rates
What are the general shape of population growth curves?
geometric, exponential
s-shaped, logistic
What is the relation of N, t, and r in an exponentially growing population?
dN/dt = rN
dN/dt = change in population density over time
r = per capita rate of increase
N = population density
What are three examples of logistic growth?
food becomes limited and environment grows toxic,
breeding space becomes limited
attachment space becomes limited
Define carrying capacity
the population density at which births = deaths, and there is no net growth
Discuss a logistic population growth (graph)
early exponential growth when small population hasn’t depleted resources
population gets large enough that some factor beings to limit it; growth curve starts to bend back down
population density is so high that resources are only sufficent to support enough births to replace deaths (no net population growth)
In a logistic curve, __ goes to zero as population density approaches __ __
dN/dt
carrying capacity (k)
What is the equation for logistic population growth?
dN/dt = rmax N (1-N/K)
Equation for logistic growth reveals __ in growth rate at __ population densities
slowdown
high
Recognize that the __ and __ environmental factors that influence population density are, themselves, also __ over time.
physical, biotic
changing
What does r max look like for exponential and logistic graphs?
expo - constant, straight line
linear decrease to 0 which is k
For a cactus finch, more __ means more __ and therefore more __
rainfall, food, offspring
Discuss the population dynamics of an excess rainfall population of prickly pears
massive cactus mortality from intense rainfall
exploitation of cactus by finch kept population low during drought years
The effect of density dependent factors on a population depend on the impacted __ __
population’s density
If a population of plants is more sensitive to a disease when the population is large (high N) than when the population is small (low N), the disease has a __ __ influence on the population of plants
density dependent
If 50% of the plants in a plant population die when there is a frost, regardless of the plant population density, then frost has a __ __ influence on plant production
density independent
Influence of density independent factors ___ depend on the density of the population being affected
does not
