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Ecology Exam 2

=evaporation of water from leaves, via stomata
-surface tension of water basis for this
-evaporation of water creates negative pressure within leaves, which pulls more water up from the ground
the process by which water changes from liquid form to an atmospheric gas
Water potential
= capacity of water to do work (forces x time)
-pure water =0
-water potentials in nature generally negative
Matric forces
=reduction of water potential due to water surface tension inside plant cells/vessels (due to capillary action)
Metabolic water
-plants use water, carbon dioxide, chlorophyll and sunlight to produce sugar (glucose) and oxygen
-animals can acquire water simply by metabolizing food, which relases H20 used during photosynthesis
ex) kangaroo rat and seeds
-produce there are own food/energy
Chemosynthetic autotroph
: energy from inorganic molecules
=sulfur oxidizing Archaea and Bacteria, in soil, sediments, and aquatic env.
-form bases of hydro-thermal vent exosystem-mutualism with giant tube worms
=nitrifying bacteria
C3 plant
-C3 carbon fixation
C4 plant
-grasses, corn, sugar cane etc
pros- C02 conc for efficiency of Calvin cycle, stomatal resistance can be high because of high affinity of PEP carboxylase for CO2
cons- recovering PEP from puruvate has metabolic costs, less leaf tissue for photosynthesis, not advantageous in cooler climate
Calvin-Benson cycle
=C3 plants
-process by which plants extract carbon from Co2 using enzyme RuBP carboxylase (rubisco)
CAM plant
-at night C02 enters stomata, joins PEP to form oxaloacetic acid, is vonverted to malic acid and stored in vacules
- in morning, stomata close, malic acid leaves vacuoles and is broken down to release C02,, which continues to Calvin cycle
Carbon cycle
the organic circulation of carbon from the atmosphere into organisms and back again
Chlorophyll, carotenoid pigment
Where photosynthesis occurs, pigment of photosynthesis
="other feeders", energy comes from organic molecules that is synthezize ultimately by autotrophs, captured by heterotrophs
Hydrothermal vent
- chemoautrophic archaea and baceria base of ecosystem
-mutualism with giant tube worms
Mesophyll cell
=C02 uptake occurs in C4 plants
Nitrifying bacteria
=oxidize ammonium (NH4+) to nitrite (NO2-) to yield energy
Oxaloacetic Acid (OAA)
-via point of CO2 from mesophyll cells to bundle sheath cells
at night C02 enters stomata, joins PEP to form oxaloacetic acid, is vonverted to malic acid and stored in vacules
Phosphoenol Pyruvate (PEP), PEP Carboxylase
- CO2 uptake catalyzed by PEP carboxylase (high affinity for CO2)
Phyosphoglycerate (PGA)
- two 3-carbon molecues made from calvin-benson cycle from Ribulase Biophosphate
Photosynthetically active region (PAR)
range of frequencies where plants can absorb light. 400-700 nm
the metabolic processes whereby certain organisms obtain energy from organic moelcules
Ribulase Biophosphate (RuBP), RuBP Carboxylase
-Carbon assimilated in single step, using ribulose bisphosphate (RuBP), and its enzyme RuBP carboxylase( rubisco), which has low affinity for CO2
-Called C3 because uptake of CO2 by 5-carbon RuBP produces two 3-carbon phosphoglycerate (PGA) molecules in first step of Calvin-Benson Cycle
-Occurs using chlorophyll in both palisade and spongy mesophyll cells of leaf
the small openings on the undersides of most leaves through which oxygen and carbon dioxide can move
- between C3 and C4 plants, C4 better in hot climates and lower in cold climates, C3 better in cooler climates (RuBP carboxylase more efficenit) and lower in hot climates (water loss through stomata)
= when one individual acts to increase the fitness of another at the cost of its own fitness (sacrificing reproduction or life)
Cooperative breeding
A behavioral pattern in which young animals postpone breeding and instead help their parents raise offspring.
Cooperative hunting
= individuals recognize each other and share food within social groups, including sibilings
ex) common ravens, call to recruit other ravens to a carcass so to overwelm the defenses of resident territorial ravens, lead other animals to vulnerable animals, so ravens can share with preadors
Dear enemy phenomenon
=genetically unrelated nearest neighbors (recognized by song) less aggressive towards each other feeding at ant swarm (reciprocal altruism)
Direct fitness
= directly via one's offspring
Epideictic display
=population size assesment mechanism, ie group displaces (flocking, roosts, contest between males)
=the highest level of organization of socially living organisms
-3 conditions
1) cooperative care of offspring
2) overlapping generation within a nest (offspring help parents)
3) reproductive division of labor, in which few individuals reproduce while others are physicaly or functionally sterile
Extra-pair copulation
advantage of group living
- copulation outside pair bonding
Hamilton's rule
r*B-C > 0
r=coefficient of relatedness
b=benefit associated with cooperation
c= cost accrued by cooperating
- Haploid (1n) males dvelop from unfertilized eggs, Diploid (2n) females develop from fertilized eggs
-sisters relationship= .75
sister/brother= .25
mother/daughter= .5
-for sisters the barrier to altrusistic behavior is lower
Inclusive fitness
= genes passed to future generations (direct and indirect)
Indirect fitness
= indirectly via genes shared by relatives
ex) nes helpers (help get more siblings)
Kin selection
=the selection of genes by individuals assesing the survival and reproduction of relatives (other than offspring)who possess the same genes by common descent
Reciprocal altrusim
=individuals (not necessarly related) reciprocate over time in assisting each other "you scratch my back, I'll scratch yours"
-3 conditions:
1) must recognize each other
2) interactions are long term
3) retaliation in cases when individual violates pact
ex) olive baboon, males form coalitions to break up consort pairs of estrous female and single dominant male, each male gets equal opprotunity to mate
Ultimate vs. proximate explanation
Proximate: immediate cause of the behavior (drive or physiological mechanism)
Ultimate: why does the a behavior occur, why did it occur
V. C. Wynne-Edwards
="Animal dispersion in relation to social behavior"
-hypothesized most social behaviors are mechanisms of reproductive self-restraint
ex) group displays (flocking, roosts) as "epideictic displays"
Aggregated (clumped) disperson
=unequal change of being anywhere
- mutual attraction among individuals, patchy resource distrubution
ex) chematis fremontii, limiting factors, climate, soil and biological interactions
Capture-mark-recapture method
-identify sample of animals, release into larger population, resample after short time (too short for mortality or dispersal)
M/N= m/n
M= total number marked, released
N=actual population size
m=marked indiv in second sample
n= total captured in second smapling
ex) whales
Chi-squared test
- used to determine if results are statistically signifacant
=patterns of individuals' distribution in space
-Some interactions cause individuals to spread out within environment (e.g., competition for substrate, territoriality)
Spaced out (even) dispersion
=individuals uniformly spaced
-exclusive use of area (resource competition, territorality)
ex) old creosote brush
Poisson Model
=mathemetically model to test disperson
-assumes each indiv. has equal probability of occuring in any area
Prob(x): M^x*e^-m/x!
= a group of individuals of a single speices inhabitating the specific area
Random dispersion
=equal chance of individuals being anywhere
-uniform or random distribution of resources
-different forms:
-small geographic range
-narrow habitat tolerance
-small local population
-random sampling og population
ex) Christmas Bird Count etc
statistical hypothesis testing
ex) American redsarts in Jamacia
Cohort effect
=dominance of population dynamics by particular cohort(s)
ex) excellent Lake Erie whitefish spawin in 1944
=How populations change over time
Dispersal behavior, rates
Life tables
Survivorship patterns
Calculating population growth rates
Dynamic (cohort) life table
=all individuals withiin an area born/germinated in population in the same time interval
Emmigration, immigration
the movement individuals out of a population, can cause a population to decrease in size VS. the movement of individuals into an area, is another factor that can cause a population to grow
=births, the average number of offspring produced by female during age interval
Generation time
=time it takes for an organism to reproduce
--> bigger org=longer reproductive time
- rate of population growth
-can be calculated from life tables
Life expectancy
= the average number of future age classes an individual can expect to reach at each age
Life table
=Informative way to track how a population grows and changes
-Invented by insurance industry to calculate odds of humans living to particular ages
Malthusian parameter (r)= intrinsic rate of pop growth
=per capita rate of increase
ln (Ro)/T
Net reproductive rate (R0)
-number of offspring an individual expects to produce over its lifetime
Static (time-specific) life table
= gives a snapshot in time, based on age distribution, for long-lived or highly mobile animals that can't be tracked easily from cradle to grave
Survivorship curve
-Comparing survivorship patterns directly (conventionally set n0 = 1000) using survivorship curve: log(lx) as function of age
Type I, II, III survivorship patterns
I: juvenile survivorship is high and most mortality occurs among older individuals (humans)
II: individuals die equal rates regardless of age (bird, reptiles)
III: individuals die at high rates as juvenilles and then at lower rates later in life (fish, plants)
doubling time
=amount of time a population takes to double its population size
Exponential model
=species that grow and reproduce continually
ex) humans
Geometric model
=organisms with discrete, seasonal reproduction
ex) rabbits, California quail
Malthusian parameter
intrinsic rate of increase
Multiplicative process
=population growth is, population change per unity time interval depends just on population size at a particular time and on each individuals contribution to population size in its lifetime
Population growth
=new population= old population multiplied by each individuals contribution to the next generation
Carrying capacity (K)
Density-dependent factors
= limitation is proportional to population size
Density-independent factors
=limiting factors are not proportional to population size
-abiotic factors (weather), and biotic independent of population size(disease)
Differential equation
the mathematical formulation corresponding to a continuous time model; an equation involving derivatives
Dynamic Equilibrium
=even distrubution of desert shrub, that disproportionate mortality ir young indiv is most important. Clumped to random as they grow
Intra-specific competition
=within species competition for limiting resource
Population limitation
=any factor that keeps populations from growing
Logistic model
=relationship between population density and rate of increase re linear, s shaped
Population regulation
=the tendency of a population to stay within some bounds of abundance if displaced from it