Exam 1
Ecology
the scientific study of the relationship between organisms and their environments
abiotic
physical conditions experienced by an organism (interactions between organisms and their physical environments
biotic
the biological or living components that make up an organism’s surroundings (interactions among living organisms)
Organism
fundamental unit of ecology
habitat
place or physical setting in which an organism lives
niche
range of ocnditions that an organism can tolerate and it’s role in the ecosystem
organism
fundamental unit of ecology (no smaller unit in biology has an independent life in the environment)
population
a group of individuals of a single species inhabiting a specific area
community
an association of interacting species living in a particular area
ecosystem
a biological community plus all of the abiotic factors influencing that community
biosphere
the total global ecosystem, all of the environments and organisms of the earth
organismal ecology
study of how indivudals’ adaptations and choices affect their reproduction and adaptations and choices affect their reproduction and survival (three subdisciplines: evolutionary, behavioral, and physiological ecology)
evolutionary ecology
changes in gene frequencies in a population over time; descent w/ modification
behavioral ecology
how the behavior of an organism contributes to its survival and reproductive success, which in turn affects population size (tent caterpillars)
physiological ecology
how organisms are physiologically adapted to their environment and how the environment impacts the distribution of species
population ecology
study of the growht, fluctuation, and interactions of populations
community ecology
study of the diversity and relative abundance of different kinds of organisms living in one place
ecosystem ecology
the study of the movement of energy and nutrients through communities (foodchains)
taxonomic
plant ecology, animal ecology, microbial ecology, avian ecology, etc
time/place
marine ecology, tropical ecology, freshwater ecology, paleoecology
processes
behavioral ecology, physiological ecology, evolutionary ecology
scale
the dimension in time or space over which variation is perceived
scale, time, space
three things to consider when studying ecology
MacArthur
studied the ecology of five species of warblers in spruce forests in north america, predicted that species with identical ecological requirements could not coexist indefinitely (due tocompetitive exclusion)
Eutrophication
nutrient enrichment of a lake which can cause rapid algal growth and decrease oxygen levels
Phosphorus
main cause of eutrophication
null hypothesis
a hypothesis that is set up to be nullified or refuted, stated in terms of “no difference” between observed results and expected results
observation
the investigator notes a phenomenon
hypothesis formulation
the investigator poses a question about the observation in a way that it can be tested by experiments or field observations
prediciton
the investigator predicts what s/he velieves is true about the hypothesis
study design
the investigator designs a study which will yield data to either support or refute the null hypothesis
data collection
the study is conducted and data are collected
data analysis
the data are subjected to rigorous statistical tests to determine whether any deviation from the expected result is truly meaningful or merely due to chance
conclusion
investigator rejects or fails to reject the null hypothesis
microcosisms
small world-replicate essential features of an ecosystem in a laboratory or field setting
model
an hypothesis that yield predictions that can be tested by comparing them to what really occurs
ultimate
explanation at the evolutionary level
proximate
current explanation

global, regional, local, microclimate

 

need to study and understand the physcial environemnt at what different scales
decreases
From the equator poleward, temperature increases or decreases?
decreases
from the equator poleward, precipitation increases or decreases?
seasonality
variation in orientation of earth’s axis relative to sun creates
30
percentage of solar radiation that is reflected back into space
19
percentage of solar radiation that is absorbed by the atmosphere and clouds
51
percentage of solar radiation that reaches the earths surface
Greenhouse effect
gases in the atmosphere absorb the heat waves that are reflected from the earths surface, they trap the heat and help keep the earth warm enough to support life
Water vapor, CO2, CH4(methane and nitrous oxide), CFCs
four greenhouse gases
global warming
slow but steady increase in the earth’s surface temperature, due to excess greenhouse gases
coral reefs
species that need warm water to secrete their calcium carbonate exoskeleton
ectotherms
organisms that obtain their heat from external sources
endotherms
organisms that generate their own heat (metabolic heat)
poikilotherms (heterotherms)
organisms that have a body temperature that fluctuates w/ ambient
homeotherms
organisms that have a constant body temperature (maintained in a narrow range)
radiation
energy absorbed and emitted in the form of electromagnetic radiation (from sun and other objects)
conduction
transfer of heat between objects in direct contact with one another
convection
direct transfer of heat by the movement of a fluid (air and water)
evaporation
heat loss as water is evaporated from an organisms surface
homeostasis
an organism’s ability to maintain constant internal conditions in varying environments
negative feedback
when a system deviates from set point, various responses are activated to return system to set point
thermal neutral zone
the range of environmental temperatures over which the metabolic rate of a homeothermic animal does not change
adapatation
inherited traits that enhance an organism’s ability to survive and reproduce in its environment
dormancy
becoming inactive until conditions become more favorable (hibernation, torpor, etc)
migration
moving to another location where conditions are more favorable
storage
relying on resources accumulated when conditions are more favorable (internally or externally)
shivering, brown fat, regulating blood flow to extremities
strategies of endotherms for keeping warm
shivering
contracting muscles to generate internal heat
brown fat
found in mammals that hibernate (also many newborn mammals, including us)- specialized heat producing tissue
counter-current heat exchange

a mechanism that conserves body heat by minimizing heat loss in the extremities and returns heat to the body core

 

torpor
facultative hypothermia to conserve energy
supercooling
body fluids at or below freezing, absence of nucleating agents
antifreeze compounds
lower the freezing point of body fluids, glycoproteins an dpolypeptides
tolerate freezing
mechanisms to prevent cell damage, ice crystals only form in extracellular body fluids
Bergmann’s rule
body mass of animals increases with latitude
Allen’s Rule
among closely related endothermic vertebrates, those living in colder environments tend to have shorter appendages than those living in warmer environments, greater surface area=greater hea tloss
Diapause
state of arrested development, triggered by env stimuli that precede unfavorable conditions. occurs in insects usually occurs during the egg or pupae stage
denaturing
due to heat, proteins can unflod or bind to other proteins, this is known as
heat shock proteins
prevent denaturing of proteins, help move damaged proteins out of a cell
aestivation
a period of deep and prolonged sleep that occurs in response to heat and drought

relaxation of homeostasis, avoidance, specializations

 

three major responses endotherms use to deal with heat
relaxation of homeostasis
survive in deserts by tolerating greater variation in body temperature and body-water content
avoidance
avoid desert conditions by behavioral means (migrate, burrow)
specializations
physiological mechanisms such as torpor in response to shortages of food or water
performance
how enviornmental conditions affect the phsyiology and behavior of organisms
range of tolerance
entire range of conditions over which a psecies is able to survive
treeline/timberline
the point on a mountainside (altitude) where trees stop growing
relative humidity
a measure of the ewater ocnent of air relative to its content at saturation
turgor pressure
hydrostatic pressure that increases as water enters plant cells
abscission
drough deciduosness, water stressed plants dropping their leaves
turnover time
time required for the entire volume of a resevoir of water to be renewed (evaporation and precipitation)
specific heat
heat needed to raise the emperature of 1g of a substance by 1 degree celcius
osmosis
movement of water across a semipermeable membrane
isosmotic
body fluids and external fluid have the same concentration of solutes (water moves in and out at same rate)
hyperosmotic
body fluids have a higher concentration of solutes than the external environment (water moves in)
hypoosmotic
body fluids have a lower concentration of oslutes than the external environment (water moves out)
freshwater fish
have an internal salt concentration higher than that of surrounding water (hyperosmotic)
saltwater fish
marine organisms have internal salt concnetration lower than that of water (hypoosmotic)
acids
molecules that release hydrogen ions in solution
base
lowers the H plus concentration by releasing OH-
4 degrees
water is most dense at
0 degrees
water is least dense at

increases

 

density of water increases as salinity
littoral zone
shallow water along shore where rooted aquatic plants can grow
limnetic zone
open water away from shore
epilimnion
warm surface layer
metalimnion
middle layer where temperature changes substantially with depth; aka thermocline
hypolimnion
deepest layer; cold dark water
epilimnion, metalimnion, hypolimnion
3 main depth zones of limnetic zone
littoral zone (intertidal zone)
shallow shoreline (ocean structure)
neritic zone
coast to margin of continental shelf (oceans structure)
oceanic zone
beyond continental shelf (ocean structure)
benthic
habitats on the bottom of the ocean
pelagic
habitat off the bottom of hte ocean, regardless of depth
diel
daily patterns of distribution/abundance of animals
law of tolerance
the success of an organism (population) can be controlled by the deficiency or excess of any factor that approaches the limits of tolerance for that organism
stenotypoic:
narrow tolerance range (specialists)
eurytopic
broad temperature range (generalist)
fundamental niche
the physical conditions under which a species might live in the absence of interactions with other
realized niche
the actual niche of a species whose distribution is restricted by biotic interactions such as competition, predation, disease, and parasitism
autotrophs
organisms that obtain their energy from inorganic sources
photoautotrophs
energy from light
chemoautotrophs
energy from oxidation of inorganic compounds (hydrogen and sulfide ammonia)
heterotrophs
organisms unable to manufacture their own food from inorganic materials and thus rely on other organisms, living and dead, as their source of energy
photosynthetically active radiation
wavelengths of light b/w 400 and 700 nm, photosynthetic organisms use as a source of energy
phototaxis
grow toward light
C3
used by most plants and algae
C4
used by many grasses in warm environments
CAM
used by succulent plants in arid environments
herbivores
feed on plants
carnivores
feed on animal flesh
detritivores
feed on non-living orgnaic matter
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