1. All organisms are made of cells. Cells are the smallest unit of life

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2 1. All organisms are made of cells Cells are the smallest unit of life

3 2. All organisms need energy Any living organism needs energy to live They take in and use energy.

4 3. All organisms respond to the environment What happens to an organism depends on the environment they are living in.

5 4. All organisms reproduce Living organisms can make more of themselves Two types: asexual sexual.

6 5. All organisms grow and develop Get bigger as they get older.

7 6. All organisms carry DNA Carry their own genetic code Traits are passed to offspring

8 7. Internal Balance (Homeostasis) Living things maintain stable internal conditions Examples Temperature Water Balance Heart Beat

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10 Key Knowledge: 1. Matter cycles, energy flows 2. Abiotic factors cause changes in biotic factors in a ecosystem

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12 Abiotic: Non-living parts of the environment Soil Sunlight Climate Temperature Rainfall Nutrients

13 Biotic: living parts of the environment Plant Animals Decomposers (Bacteria and Fungus)

14 General Organization Organism= any individual living thing Population= Individual organisms of a single species in one area. Community= more than one population living in the same area.

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16 Different species of fish Different species of corals (animals) Example of a Community Starfish (animal) Algae (microscopic plants)

17 General Organization Ecosystem= All the populations and abiotic factors in an area. Habitat = the environment that a particular species prefers within an ecosystem Niche= the role that an organism fills job Biomes= Ecosystems with similar characteristics.

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19 Characteristics of a Biome No distinct boundaries Defined by types of plants Similar climate conditions, but may be located in a totally different part of the world (Africa and Asia) Classification of biomes: land biomes water biomes (marine or freshwater)

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21 Can make their own food through energy from the sun or inorganic substances AKA: Primary Producer

22 Obtains energy by eating other organisms, AKA: Consumers

23 Types of Consumers Primary consumers: eat producers (herbivores) Secondary consumers: eats both producers & consumers (omnivores) Tertiary consumers: top predator (carnivore)

24 Trophic levels are a way of identifying what kinds of food an organism uses. 1 st trophic level= primary producers 2 nd trophic level= primary consumers 3 rd trophic level= secondary consumers 4 th trophic level= tertiary consumer

25 Decomposers & Scavengers Decomposers feed on wastes & dead material from all trophic levels Ex: bacteria, fungi Scavengers are consumers that eat dead animals (like road kill) Ex: vulture

26 Energy in an ecosystem is transferred (cycles) through the trophic levels of that ecosystem

27 Biomass and Energy Transfer 1 hawk 10 snakes 100 mice feed 1000 plants feed Rule of 10****- Only 10% of the energy is transferred to the next organism. Biomass- amount of living matter, number of organisms, or determines the amount of energy

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29 Very few animals feed on only one food source, food webs are a more accurate picture of how animals feed.

30 Biological Magnification The build-up of toxins in living organisms with movement up the trophic levels. Toxins collect in at the top of food web because top consumers eat so much. Examples:

31 DDT: Dichlorodiphenyltrichloroethane Developed during WWII as a pesticide Very high levels of DDT were found in top consumers. DDT is stored in fat. Organisms died or had reproductive problems Banned in US and Canada during the 70 s. Still found in almost all living things Developing countries are still use DDT

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35 Community Interactions In order to sustain an environment, organisms and abiotic factors interact EXAMPLES: Symbiosis Succession

36 Forms of Species Interaction Symbiosis: relationships between two species (3 types) 1. Parasitism: one organism benefits at another s expense (humans and tape worm) 2. Commensalism: one organism benefits while the other is unaffected (anemone and clown fish) 3. Mutualism: both organisms benefit from the interaction (rhino and bird)

37 Forms of Species Interaction Continued Competition: two species are fighting for the same resources Predation: one species hunts the other Ecological succession: change in the types of species in a community observed over time

38 Invasive Species A species that is brought by HUMANS into a new environment and outcompetes the ones already there. They have no competitors, no diseases so they 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

39 Keystone Species A species that plays a key role in the ecosystem Increases biodiversity by keeping the number of each species in balance Examples Sea otter in the kelp forests Beavers in rivers Sea Otter Beaver

40 Succession

41 Why does succession happen? Communities & environments change over time

42 1) Primary Succession When communities form in new areas Ex: volcanoes, rocks, etc

43 Steps of Primary Succession 1. Pioneer species appear lichens (grow on rock & turn it into soil) Pioneer Species: the first organisms to occupy an area 2. Grass & small plants appear 3. Weeds & shrubs 4. Shallow trees (ex: pine trees) 5. Climax community stable & final stage (ex: deciduous trees)

44 Climax Community A community that has achieved stability and species diversity

45 2) Secondary Succession Occurs in areas that were cleared by disturbance (fire, tornado, floods, etc) faster than primary (soil already formed) Same as primary except pioneer species are grasses instead of lichens

46 Succession leads to..

47 FACTORS THAT AFFECT POPULATION GROWTH 1.Birth Rate 2.Death Rate 3.Immigration (movement into an area) 4.Emigration (Movement, exiting an area)

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49 Exponential Growth J-shaped curve on a graph Population doubles every generation Humans are reproducing this way! Humans - Trouble ahead?

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51 Logistic Growth S shaped curve on graph How real growth looks Populations grow fast early, then slow down, as we get closer to CARRYING CAPACITY

52 Biomass and energy transfer at the lowest trophic level determines the carrying capacity of the ecosystem.

53 Carrying Capacity Maximum # of individuals a population can support Populations will increase to carrying capacity, and they decrease again once they have reached it.

54 Limits to Pop. Growth 1. Density-dependent limiting factors - reduce population growth with that depends on current population size Affect crowded populations Disease Competition (for shelter, food, water) Predation (predator eats prey)

55 How might the bubonic plague have been different if the medieval populations didn t live so close to each other?

56 2. Density-independent limiting factors environmental factors affecting a population regardless of size Affect all populations (crowded or not) Weather Natural disasters (fire, etc) Human activities

57 New Orleans, LA Gulf Port, MS Would the physical effects of hurricane Katrina be any different in a town of 100, then in a town of 100,000?

58 All matter essential for life moves in cycles between living things & the environment Examples of cycles: carbon cycle water cycle nitrogen cycle

59 Why is carbon important to us? 1) Carbon is used to make hair, muscle, & skin 2) Carbon stores energy so living things can think, move, etc 3) Fossil fuels (gas, coal, oil) are made from carbon

60 Where is carbon found in the environment? 1. atmospheric gas (CO 2 ) 2. rocks (limestone, diamonds) 3. fossil fuels (oil, coal, etc.)

61 How does carbon enter living things? 1) CO 2 gas enters plants 2) Photosynthesis allows plants to change CO 2 into a sugar 3) Animals then get carbon by eating the sugar found in plants

62 How does carbon get back into the environment? 1. Plants & animals release CO 2 during respiration 2. Burning of wood & fossil fuels 3. Using electricity, (most power plants use fossil fuels) 4. Cow farts (seriously) 5. Decomposition when bacteria and fungus break down tissue of dead things

63 How are fossil fuels formed? 1. When living things die & fall to the bottom of water, they are buried & compressed 2. They eventually form coal, petroleum, or natural gas

64 So what s the cycle? the 2 main steps are photosynthesis & respiration!

65 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

66 Future Predictions Due to humans using more fossil fuels, more CO 2 is released each year this may result in global warming since CO 2 traps heat (remember the greenhouse effect)

67 What is global warming?

68 Facts about Nitrogen 78% of air is nitrogen gas (N 2 ) Living things can t use nitrogen when it s a gas (N 2 )

69 Why do living things need Nitrogen? To make amino acids & proteins To make DNA

70 Step #1 The Nitrogen Cycle Nitrogen gas (N 2 ) is found in the atmosphere

71 Step #2 Nitrogen Fixation : Bacteria living at the roots change the N 2 gas into a usable form like ammonia or nitrates Lightning also fixes nitrogen

72 Step #3 Plants then use the ammonia or nitrates in the soil Step #4 Animals get nitrogen from plants by eating them

73 Step #5 When plants & animals die, the nitrogen in them is released back into the atmosphere as a gas (N 2 ) This is done by denitrifying bacteria Step #6 Nitrogen gas is released back into the atmosphere

74 What are the two process that are responsible; for cycling Carbon in the environment? What things add carbon? Which things take it away? Photosynthesis and Cellular Respiration Photosynthesis : take it away Cellular Respiration, Fossil Fuels and Decaying organisms add it.

75 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

76 HUMAN IMPACT A Sad True Story

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78 An Ecological Mystery Long term study of sea otter population along the Alaskan and Aleutian Islands 1970: Sea Otters healthy and populations growing 1990: Sea Otter # s declining Maybe due to emigration, not deaths 1993: 800 km area in Aleutian Islands studied Sea Otter # s reduced by 50%

79 Vanishing Sea Otters 1997: Study of area repeated Sea Otter pop. had declined by 90% 1970: > 53,000 Otters in the study area 2012: < 2800 Why? Reproductive issues Starvation, pollution, disease?

80 Cause 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

81 No Big Deal.. Right? Declines in ocean fish due to over fishing and climatic changes led to a reduction in food for sea lions & seals, so their # s decreased This forced the orcas to enter into the coastal waters where they consumed sea otters. Sea otters normally feed on sea urchins. As sea otters decreased, the urchins numbers increased.

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83 Urchins eat kelp, and the large numbers of urchins damaged kelp forests. The decline in the kelp forests has had an impact on many others species because of the decrease of oxygen and an increase in carbon dioxide in the water. Other Species Affected Bald Eagle Mussel Sea Stars Seagulls

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