1. all organisms are made of cells cells are the smallest unit of life
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3. All organisms respond to the environment
What happens to an organism depends on the environment they are living in.
4. All organisms reproduce
Living organisms can make more of themselves
Two types:– asexual – sexual.
7. Internal Balance (Homeostasis)
Living things maintain stable internal conditions
Examples– Temperature– Water Balance– Heart Beat
Key Knowledge:
1.Matter cycles, energy flows
2.Abiotic factors cause changes in biotic factors in a ecosystem
AbioticAbiotic: : Non-living parts of the Non-living parts of the environmentenvironment
Soil Soil SunlightSunlight ClimateClimate TemperatureTemperature RainfallRainfall NutrientsNutrients
BioticBiotic: : livingliving parts of the parts of the environment environment
PlantPlant Animals Animals Decomposers Decomposers
(Bacteria and Fungus)(Bacteria and Fungus)
General OrganizationGeneral Organization
OrganismOrganism= = any individual living any individual living thingthing
PopulationPopulation= Individual organisms = Individual organisms of a single species in one area.of a single species in one area.
CommunityCommunity== more than onemore than one populationpopulation living in the same area.living in the same area.
Example of a Example of a CommunityCommunity
Different species of fish
Different species of corals (animals)
Starfish (animal)
Algae
(microscopic plants)
General OrganizationGeneral Organization EcosystemEcosystem= = All All the the populationspopulations and and
abioticabiotic factors in an area. factors in an area. HabitatHabitat == the environment that a the environment that a
particular species prefers within an particular species prefers within an ecosystem ecosystem
NicheNiche== the role that an organism fills the role that an organism fills “job”“job”
BiomesBiomes== Ecosystems with similar Ecosystems with similar characteristics.characteristics.
Characteristics of a BiomeCharacteristics of a Biome
No distinct boundariesNo distinct boundaries Defined by types of Defined by types of plantsplants Similar climateSimilar climate conditions, but may be conditions, but may be
located in a totally different part of the located in a totally different part of the world (Africa and Asia)world (Africa and Asia)
Classification of biomes:Classification of biomes:– land biomes land biomes –water biomes (marine or freshwater)water biomes (marine or freshwater)
Types of ConsumersPrimary consumersPrimary consumers: eat producers : eat producers
((herbivoresherbivores))
Secondary consumers:Secondary consumers: eats both eats both producers & consumers (producers & consumers (omnivoresomnivores))
Tertiary consumers:Tertiary consumers: top predator top predator ((carnivorecarnivore))
Trophic levelsTrophic levels are a way of identifying are a way of identifying what what kinds of foodkinds of food an organism uses. an organism uses.
1st trophic level= primary producers
2nd trophic level= primary consumers
3rd trophic level= secondary consumers
4th trophic level= tertiary
consumer
Decomposers & ScavengersDecomposers & Scavengers
Decomposers feed on wastes & dead Decomposers feed on wastes & dead material from all trophic levelsmaterial from all trophic levels
Ex: bacteria, fungiEx: bacteria, fungi
Scavengers are consumers that eat Scavengers are consumers that eat dead animals (like road kill)dead animals (like road kill)
Ex: vultureEx: vulture
Energy in an ecosystem is Energy in an ecosystem is transferred (cycles) through transferred (cycles) through
the the trophic levelstrophic levels of that of that ecosystemecosystem
Biomass and Energy TransferBiomass and Energy TransferBiomassBiomass- total mass of living - total mass of living material in an areamaterial in an area
Biomass and energy transfers at Biomass and energy transfers at the lowest trophic levels the lowest trophic levels determines the determines the carrying capacitycarrying capacity of of each ecosystemeach ecosystem
1 hawk1 hawk10 snakes 10 snakes
100 mice feed100 mice feed1000 plants feed1000 plants feed
Rule of 10Rule of 10****-****-Only 10%Only 10% of the energy is transferred to of the energy is transferred to the next organism.the next organism.
Very few animals feed on only one food source, food webs are a more accurate
picture of how animals feed.
Biological MagnificationBiological Magnification The build-up of toxins in living organisms The build-up of toxins in living organisms
with movement up the with movement up the trophic levelstrophic levels . . The toxins collect in organisms at the top of The toxins collect in organisms at the top of
food web because top consumers eat so food web because top consumers eat so much.much.
Examples:
DDT:DDT: DDichloroichloroddiphenyliphenylttrichloroethanerichloroethane Developed during WWII as a pesticideDeveloped during WWII as a pesticide Very high levels of DDT were found in Very high levels of DDT were found in
top consumers.top consumers. DDT is stored in fat.DDT is stored in fat.
Organisms died or had reproductive Organisms died or had reproductive problemsproblems
Banned in US and Canada during the Banned in US and Canada during the 70’s. 70’s.
Still found in almost all living thingsStill found in almost all living things Developing countries are still use DDTDeveloping countries are still use DDT
Community Interactions Community Interactions
In order to sustain an In order to sustain an environment, organisms and environment, organisms and abiotic factors interactabiotic factors interact
EXAMPLES:EXAMPLES:–SymbiosisSymbiosis
–SuccessionSuccession
Forms of Species InteractionForms of Species Interaction
1. Parasitism:1. Parasitism: one organism benefits at another’s expense (humans and tape worm)(humans and tape worm)
2. Commensalism2. Commensalism: one organism benefits while the other is unaffected (anemone and clown fish)(anemone and clown fish)
SymbiosisSymbiosis:: relationships between two species (3 types)
3. Mutualism: 3. Mutualism: both organisms benefit from the interaction (rhino and bird)(rhino and bird)
Forms of Species Interaction ContinuedForms of Species Interaction Continued
CompetitionCompetition: two species are fighting for the same resources
PredationPredation:: one species hunts the other
Ecological succession:Ecological succession: change in the change in the types of speciestypes of species in a community observed in a community observed over timeover time
Why does succession Why does succession happen?happen?
Communities & environments Communities & environments change over timechange over time
1) Primary Succession1) Primary Succession
When communities form in new areasWhen communities form in new areas– Ex: volcanoes, rocks, etcEx: volcanoes, rocks, etc
Steps of Primary SuccessionSteps of Primary Succession
1.1. Pioneer species appearPioneer species appear lichens lichens (grow on rock & turn it into soil)(grow on rock & turn it into soil)
Pioneer Species: the first organisms to occupy an area
2.2. Grass & small plants appearGrass & small plants appear
3.3. Weeds & shrubsWeeds & shrubs
4.4. Shallow treesShallow trees (ex: pine trees) (ex: pine trees)
5.5. Climax communityClimax community stable & final stable & final stage (ex: deciduous trees)stage (ex: deciduous trees)
2) Secondary Succession2) Secondary Succession Occurs in areas that were cleared by Occurs in areas that were cleared by
disturbance (fire, tornado, floods, etc)disturbance (fire, tornado, floods, etc)– faster than primary (soil already formed)faster than primary (soil already formed)
Same as primary except pioneer Same as primary except pioneer species are grasses instead of lichensspecies are grasses instead of lichens
1.Birth Rate
2.Death Rate
3.Immigration (movement into an area)
4.Emigration (Movement, exiting an area)
FACTORS THAT AFFECT FACTORS THAT AFFECT POPULATION GROWTHPOPULATION GROWTH
Exponential GrowthExponential Growth J-shaped curveJ-shaped curve on a graph on a graph Population doubles every generationPopulation doubles every generation Humans are reproducing this way! Humans are reproducing this way!
Humans - Trouble ahead?Humans - Trouble ahead?
Logistic GrowthLogistic Growth S–shaped curveS–shaped curve on graph on graph How real growth looksHow real growth looks Populations grow fast early, then slow Populations grow fast early, then slow
down, as we get closer to down, as we get closer to CARRYING CARRYING CAPACITYCAPACITY
Biomass
and
energy transfer
at the lowest
trophic level determines the
carrying capacity of the ecosystem.
Carrying Capacity Carrying Capacity Maximum # of individuals a population Maximum # of individuals a population
can supportcan support– Populations will Populations will increaseincrease to to carrying carrying
capacitycapacity, and they , and they decrease againdecrease again once once they have reached it.they have reached it.
Limits to Pop. GrowthLimits to Pop. Growth1. 1. Density-dependent limiting factors Density-dependent limiting factors - -
reduce population growth; depends on reduce population growth; depends on current population sizecurrent population size
– Affect crowded populationsAffect crowded populations DiseaseDisease Competition (for shelter, food, water)Competition (for shelter, food, water) Predation (predator eats prey)Predation (predator eats prey)
How might the bubonic plague
have been different if the
medieval populations didn’t live so close to each
other?
2. 2. Density-independent limiting factorsDensity-independent limiting factors – – environmental factors affecting a environmental factors affecting a population regardless of sizepopulation regardless of size
– Affect all populations (crowded or not)Affect all populations (crowded or not) WeatherWeather Natural disasters (fire, etc)Natural disasters (fire, etc) Human activitiesHuman activities
Would the Would the physical physical effects of effects of hurricane hurricane Katrina be Katrina be
any different any different in a town of in a town of
100, then in a 100, then in a town of town of
100,000?100,000?
New Orleans, LA
Gulf Port , MS
All matter essential for life moves in All matter essential for life moves in cycles between living things & the cycles between living things & the
environmentenvironment
Examples of cyclesExamples of cycles::carbon cyclecarbon cyclewater cyclewater cyclenitrogen cyclenitrogen cycle
AKA: Nutrient Cycles
AKA: Nutrient Cycles
Why is carbon important to usWhy is carbon important to us??
1) Carbon is used to make hair, 1) Carbon is used to make hair, muscle, & skinmuscle, & skin
2) Carbon stores energy so living 2) Carbon stores energy so living things can think, move, etc things can think, move, etc
3) Fossil fuels (gas, coal, oil) are 3) Fossil fuels (gas, coal, oil) are made from carbonmade from carbon
Where is carbon found in the environmentWhere is carbon found in the environment??
1.1. atmospheric gas (COatmospheric gas (CO22))
2.2. rocks (limestone, diamonds)rocks (limestone, diamonds)
3.3. fossil fuels (oil, coal, etc.) fossil fuels (oil, coal, etc.)
How does carbon enter living thingsHow does carbon enter living things??
1) CO1) CO22 gas enters plants gas enters plants
2) Photosynthesis allows plants to 2) Photosynthesis allows plants to change COchange CO22 into a sugar into a sugar
3) Animals then get carbon by eating 3) Animals then get carbon by eating the sugar found in plantsthe sugar found in plants
How does carbon get back How does carbon get back into the environmentinto the environment??
1. Plants & animals release CO1. Plants & animals release CO22 during during respirationrespiration
2. Burning of wood & fossil fuels2. Burning of wood & fossil fuels
3. Using electricity, (most power plants use 3. Using electricity, (most power plants use fossil fuels)fossil fuels)
4. Cow farts (seriously)4. Cow farts (seriously)
5. Decomposition when bacteria and fungus 5. Decomposition when bacteria and fungus break down tissue of dead thingsbreak down tissue of dead things
How are fossil fuels formedHow are fossil fuels formed??
1.1. When living things die & fall to When living things die & fall to the bottom of water, they are the bottom of water, they are buried & compressed buried & compressed
2.2. They eventually form coal, They eventually form coal, petroleum, or natural gaspetroleum, or natural gas
So what’s the cycle?So what’s the cycle?
the 2 main steps are the 2 main steps are photosynthesis & respiration!photosynthesis & respiration!
The Carbon Cycle
The movement of carbon through the environment
2 major driving forces
1. Photosynthesis- plants and algae take up CO2 from the air or water to make sugar
2. Cellular Respiration- consumers use sugar for energy and release CO2 into the air or water
Future PredictionsFuture Predictions
Due to humans using more fossil fuels, Due to humans using more fossil fuels, more COmore CO22 is released each year is released each year
this may result in global warming since this may result in global warming since COCO22 traps heat (remember the traps heat (remember the
greenhouse effect)greenhouse effect)
Facts about NitrogenFacts about Nitrogen 78% of air is nitrogen gas (N78% of air is nitrogen gas (N22)) Living things can’t use Living things can’t use
nitrogen when it’s a gas (Nnitrogen when it’s a gas (N22))
Why do living things need Why do living things need Nitrogen?Nitrogen?
To make amino acids & proteinsTo make amino acids & proteins To make DNATo make DNA
The Nitrogen CycleThe Nitrogen Cycle
Step #1Step #1Nitrogen gas (NNitrogen gas (N22) is found in the ) is found in the
atmosphereatmosphere
Step #2Step #2””Nitrogen Fixation”Nitrogen Fixation”: Bacteria : Bacteria
living at the roots change living at the roots change the Nthe N22 gas into a usable gas into a usable
form like ammonia or form like ammonia or nitratesnitrates
Lightning also “fixes” nitrogenLightning also “fixes” nitrogen
Step #3Step #3Plants then use the ammonia Plants then use the ammonia
or nitrates in the soilor nitrates in the soil
Step #4Step #4Animals get nitrogen from Animals get nitrogen from
plants by eating themplants by eating them
Step #5Step #5 When plants & animals die, the nitrogen When plants & animals die, the nitrogen
in them is released back into the in them is released back into the atmosphere as a gas (Natmosphere as a gas (N22))
This is done by denitrifying bacteriaThis is done by denitrifying bacteria
Step #6Step #6Nitrogen gas is released back into the Nitrogen gas is released back into the
atmosphereatmosphere
What are the two process What are the two process that are responsible; for that are responsible; for cycling Carbon in the cycling Carbon in the environment?environment?
What things add carbon?What things add carbon?Which things take it away?Which things take it away?
Photosynthesis and Cellular RespirationPhotosynthesis and Cellular RespirationPhotosynthesis : take it awayPhotosynthesis : take it awayCellular Respiration, Fossil Fuels and Cellular Respiration, Fossil Fuels and Decaying organisms add it.Decaying organisms add it.
Breaking the Water Cycle The only way for water to get back to
the atmosphere is through transpiration (plant sweating)
When we cut down trees they no longer transpire
So water does not get into the air to become rain
The area becomes a desert in a very short time period– Really bad in rainforest regions,
because the soil is so shallow
Invasive SpeciesInvasive Species A species that is brought by A species that is brought by HUMANSHUMANS into into
a new environment and a new environment and outcompetesoutcompetes the the ones already there.ones already there.
They have no competitors, no diseases so They have no competitors, no diseases so they outgrow other populationsthey outgrow other populations
Example: Africanized honey bees, which will take over the hive of the honey bees.
Example: Zebra mussels attach to boats and cover piers within months
Keystone SpeciesKeystone Species A species that plays a key role in the A species that plays a key role in the
ecosystemecosystem Increases biodiversity by keeping the Increases biodiversity by keeping the
number of each species in balancenumber of each species in balance– ExamplesExamples
Sea otter in the kelp forestsSea otter in the kelp forests Beavers in rivers Beavers in rivers
BeaverBeaverSea OtterSea Otter
An Ecological MysteryAn Ecological Mystery
Long term study of sea otter population along the Long term study of sea otter population along the Alaskan and Aleutian IslandsAlaskan and Aleutian Islands
19701970: Sea Otters healthy and populations: Sea Otters healthy and populationsgrowinggrowing
19901990: Sea Otter #’: Sea Otter #’ss declining declining– Maybe due to emigration, not deathsMaybe due to emigration, not deaths
19931993: 800 km area in Aleutian Islands studied: 800 km area in Aleutian Islands studied– Sea Otter #’Sea Otter #’ss reduced by 50% reduced by 50%
Vanishing Sea OttersVanishing Sea Otters
19971997: Study of area repeated: Study of area repeated Sea Otter pop. had declined bySea Otter pop. had declined by 90% 90%
– 1970: 1970: >> 53,000 53,000 Otters in the study areaOtters in the study area
– 2012: 2012: << 2800 2800
Why?Why?– Reproductive issuesReproductive issues– Starvation, pollution, disease?Starvation, pollution, disease?
Cause of the DeclineCause of the Decline 1991: one researcher observed an orca
whale (killer whale) eating a sea otter. Sea lions or seals are the normal prey of
orcas. Decline in usual prey led to feeding shift. Single orca could consume 1,825
otters/year. Clam Lagoon (CONTROL GROUP), which
was not accessible to orcas, had no decline in otter population
No Big Deal.. Right?No Big Deal.. Right? Declines in ocean fishDeclines in ocean fish due to over fishing due to over fishing
and climatic changes led to a reduction in and climatic changes led to a reduction in food for food for sea lions & seals, sea lions & seals, so their #’s so their #’s decreaseddecreased
This forced the orcas to enter into the This forced the orcas to enter into the coastal waters where they consumed coastal waters where they consumed sea sea ottersotters..
Sea ottersSea otters normally feed on sea normally feed on sea urchinsurchins. . As sea otters As sea otters decreaseddecreased, the urchins , the urchins numbers numbers increased.increased.
Urchins eat kelp, and the Urchins eat kelp, and the large numberslarge numbers of of urchins damaged kelp forests.urchins damaged kelp forests.
The decline in the kelp forests has had an The decline in the kelp forests has had an impact on many others species because of impact on many others species because of the the decrease of oxygen and an increase in decrease of oxygen and an increase in carbon dioxide in the water.carbon dioxide in the water.
Other Species AffectedOther Species AffectedBald EagleBald EagleMussel Mussel Sea StarsSea StarsSeagullsSeagulls