ecology exam 1

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scientific study of the abundance and distribution of organisms in relation to other organisms and environmental conditions

ecology

scientific study of the interactions among organisms and the environment

Ernst Haeckel

coined term ecology in 1870

likened ecology to “the economy of nature”

environmentalism

ideology and social movement aimed at sustainable development and protection of natural ecosystems

living (biotic)

producers (autotrophs) and consumers (heterotrophs)

nonliving (abiotic)

things like air, soil, water, various forms of energy, organic and inorganic chemicals, etc.

chapter 1 concepts

1. ecological systems exist in a hierarchical organization

2. ecological systems are governed by physical and biological principles

3. different organisms play diverse roles in ecological ecosystems

4. scientists use several approaches to studying ecology

5. humans influence ecological systems

levels of organization in ecology

1. individual

2. population

3. community

4. ecosystem

5. landscape

6. biosphere

individual

smallest unit in biology that has separate life in the environment

population

individuals of the same species living in a particular area

community

all populations of species living together in a particular area

ecosystem

one or more communities of living organisms interacting with their nonliving physical and chemical environments

landscape

multiple ecosystems that are connected by the movement of individuals, matter, and energy

biosphere=ecosphere

all ecosystems on earth

individual apporach

understands how adaptations, or characterisitcs of an individual’s morphology, physiology, and behavior enable it to survive in an environment

population approach

seeks to understand what drives variation in the number, density, and composition of individuals over time and space

community approach

studies the diversity and interactions of organisms living together in the same place

ecosystem approach

describes the storage and transfer of energy and matter

landscape approach

studies the spatial arrangement of habitats and how this influences populations, communitites, and ecosystems

biosphere approach

examines movements of energy and chemicals over the earth’s surface

law of conservation of matter

matter cannot be created or destroyed, but can change form

first law of thermodynamics

energy cannot be created or destroyed, but can change form

dynamic steady state

ocurs when gains and losses are in balance

natural selection

a change in frequency of genes in a population through differential survival and reproduction of individuals that possess certain phenotypes

requirements of natural selection

1. individuals very in their traits

2. traits are heritable

3. variation in traits casues some individuals to experience higher fitness (survival and reproduction)

producers

convert light or chemical energy into resources

consumers

or hetertrophs- contain their energy from other organisms

mixotrophs

can switch between being producers and consumers

scavengers

consume dead animals

decoposers

break down detritus into simpler elemetns that can be recycled

detritiviores

decomposers that break down dead organic matter into smaller particles by ingesting it

predation

organism kills and consumes individual

parasitism

one organism lives in or on another

herbivory

organism consumes producers

competition

two organisms have a negative effect on each other because they depend on the same resource

mutualism

two species benefit form each other

commensalism

two species live in close association and one receives a benefit, whereas the other is unaffected

amensalism

two species live in close association and one recieves a negative effect, whereas the other is unaffected

habitat

place or physical setting where an organism lives

niche

the range of abiotic and biotic conditions an organism can tolerate

Hutchinson’s n-dimensional niche

the n-dimensional volume representing the range of environmental conditions and resourcs availiabitites in which a species can persist

requirement niche

the biotic and abiotic requirements of a species

impact niche

the effect of a spceies on the biotic and abiotic environment

scientific method

observation, hypotheses, prediction, experiment

hypothesis

an idea about how the world works

natural experiments

relies on natural variation in the environment to test a hypothesis

observational/correlational studies

make deductions from patterns in nature

mathematical models

representations of a system with a set of equations that correspond to a hypothesized relationship among the system’s components

greenhouse gases

compounds in the atmosphere that absorb infrared heat energy emitted by the earth and then emit some of the energy back toward earth

central tendency

wheere the data are centered (mode, median, mean)

dispersion

how spread out the data are (range, standard deviation, standard error)

standard deviation

Measure of the variation in the data aka “the scatter”; characterizes the variation of the population sampled

histogram

frequency diagram

standard error

standard deviation of averages; characterizes the uncertaintyy in our estimate of the mean

chapter 6 concepts

1. water has many properties that affect how aquatic organisms live

2. organisms must meet the challenges of water and salt balance

3. aquatic organisms face the challenge of exchanging gases

4. ttemperature limits the occurrence of aquatic life

omosis

net movement of water acorss a semipermeable membrane, towards a higher solute concentration

solute

a substance dissoved in water

semipermeable membrane

membrane that allows only particular molecules to pass through, (cell membranes)

osmotic potential

force with which a solution attracts water by osmosis is expressed in units of pressure (MPa). More concentrated solutions have greater osmotic potential.

freshwater fish are hyper-osmotic

internal solute concentration is higher than that of surrounding water, so fish tends to take up water from the environment

marine fish are hypo-osmotic

internal solute concentration is lower than that if surrounding water, so fish tendes to lose water to the environment

thermal optimum

the temperature in which an organism best performs

coral bleaching

loss of color in corals because they expel their symbiotic algae and can begin in summer if ocean temp. are just 1 degress higher than normal

transpiration

process by which leaves lose water through stomata due to evaporation from cell surfaces inside the leaf

stomata

tiny openings in leaves that allow gases to enter and exit leaves

matric potential

force which soil attracts and holds water

plant water potential

force which a plant tissue attracts water

electromagnetic radiation

energy from the sun and other sources; packaged in particles called photons

photosynthetically active radiation

wavelengths of light that are suitable for photosynthesis; includes 400nm (violet) to 700nm (red)

chloroplasts

specialized cell organelles in whch photosynthesis occurs in plants

C3 light reactions

convert energy from photos into chemical energy

C3 dark reactions

(calvin cycle)- use the chemical energy make sure from CO2

C4 photosynthesis

photosynthetic pathway in which CO2 is initially assimilated into a four-carbon compound

tendency for rubisoco to react with O2 is greater

1. O2 concentration is high

2. CO2 concentration inside leaf is low

3. temp. is high

CAM photosynthesis

pathway in which the initial assimiliation of carbon in OAA occurs at night

radiation

Emission of electromagnetic energy by a surface. Increases with the fourth power of absolute temp.

conduction

transfer of the kinetic energy of heat between substances that are in contact with one another

convection

transfer of heat by movement of liquids and gases

evaporation

transformation of water from liquid to gaseous states with the input of energy; removes heat from a surface; condensation, the reverse process, releases heat

thermal inertia

resistance to a change in temp. due to a large body volume

thermoregulation

process by which an organism controls the temp. of its body

homeotherms

organisms that maintain constant temp,; this allows biochemical reactions to work most efficiently

poikilotherms

organisms that do not have constant body temps.

endotherms

organisms that can generate sufficient metabolic heat to raise body temp. higher than the external environment

ectotherms

organisms with body temps, largely determined by their external environment; usually poikilotherms, but not always

blood shunting

specific blood vessels shut off, so less of an animal’s warm blood flows to cold extremities, where heat would be lost. Shunting occurs at precapillary sphincters.

countercurrent exchange

also helps to conserve heat by positioning arteries that carry warm blood away from the heart alongside veins that carry chilled blood from the extremities back to the heart