Published on December 2, 2010
Biology Unit Thirteen – ECOLOGY : Biology Unit Thirteen – ECOLOGY Fun over Thanksgiving? What did you do? Who were the first storm chasers? : Who were the first storm chasers? John Muir (1838-1914) was a naturalist who is credited for the preservation of areas such as Yosemite and the Sequoia National Park. He was also the founder of the Sierra Club. According to Howstuffworks.com, he could also be considered the first storm chaser. In an effort to know what the top of a tree experiences in a storm, Muir clung to the top of a 100 foot tall Douglas Spruce and weathered several hours in a storm with high winds. http://science.howstuffworks.com/first-storm-chaser1.htm Objectives for the day. : Objectives for the day. KEY CONCEPTS of the day. Ecology is the study of the relationships among organisms and their environment. Every ecosystem includes both living (BIOTIC) and nonliving (ABIOTIC) factors. Life in an ecosystem requires a source of energy Food chains and food webs model the flow of energy in an ecosystem. Matter cycles in and out of an ecosystem Slide 4: KEY CONCEPT Ecology is the study of the relationships among organisms and their environment. Ecologists study environments at different levels of organization. What are some of the different levels of organization called? : Ecologists study environments at different levels of organization. What are some of the different levels of organization called? Slide 6: An organism is an individual living thing, such as an alligator. Slide 7: A population is a group of the same species that lives in one area. Slide 8: A community is a group of different species that live together in one area. Slide 9: An ecosystem includes all of the organisms as well as the climate, soil, water, rocks and other nonliving things in a given area. Slide 10: A biome is a major regional or global community of organisms characterized by the climate conditions and plant communities that thrive there. Mnemonic Device Time! : Mnemonic Device Time! How will you remember the organization levels in order? Biome – ecosystem – community – population – organism (b – e – c – p – o) Ecological research methods include observation, experimentation, and modeling. : Ecological research methods include observation, experimentation, and modeling. Observation is the act of carefully watching something over time. Give one example. Observations of populations can be done by visual surveys. What kinds of things would you observe? Direct surveys for easy to spot species employ binoculars or scopes. Indirect surveys are used for species that are difficult to track and include looking for other signs of their presence. E.g. wolf howling Slide 13: Experiments are performed in the lab or in the field. Lab experiments give researchers more control. Lab experiments are not reflective of the complex interactions in nature. Why? Field experiments give a more accurate picture of natural interactions. Field experiments may not help determine actual cause and effect. Slide 14: Computer and mathematical models can be used to describe and model nature. Modeling allows scientists to learn about organisms or ecosystems in ways that would not be possible in a natural or lab setting. Computer Models canuse real data to testhypothetical situations Slide 15: KEY CONCEPT Every ecosystem includes both living (BIOTIC) and nonliving (ABIOTIC) factors. Biotic Factors. : Biotic Factors. Biotic factors are living things. Give three examples. Abiotic Factors. : Abiotic factors are nonliving things. Give three examples. Abiotic Factors. Changing one factor in an ecosystem can affect many other factors. How – give an example. : Changing one factor in an ecosystem can affect many other factors. How – give an example. Biodiversity is the assortment, or variety, of living things in an ecosystem. Some geographical areas have more biodiversity than other locations in the world. Can you give an example Slide 19: Quiz Answer Time Quiz 14-1 Slide 20: 1. What is one drawback of a field experiment? A. It does not reflect complex interactions. B. It cannot be controlled. C. It is difficult to determine cause and effect. D. There are no manipulated variables. Correct Answer = C 3. Which of the following is ordered correctly from largest to smallest? A. organism, population, community, ecosystem, biome B. ecosystem, biome, community, population, organism C. biome, ecosystem, community, population, organism D. biome, ecosystem, population, community, organism Correct Answer = C Slide 21: 5. How are computers used to model nature? A. They use real data to test hypothetical situations. B. They develop conservation plans using virtual data. C. They help wildlife managers understand the nonliving parts of a community. D. They generate data such as the amount of snow in an area. Correct Answer = A Review : Review Ecology is the study of how the living and non-living factors in an environment interact Levels of organization in ecology going from general to specific = biome, ecosystem, community, population, organism Observations include careful watching over time Lab experimentation and field experimentation have different benefits and downfalls Biotic factors are living things Abiotic factors are non-living things Biodiversity is important for survival of organisms in changing circumstances Slide 23: KEY CONCEPT Life in an ecosystem requires a source of energy. Prefix Prelude : Prefix Prelude Auto- ? Hetero- ? Photo- ? Chemo- ? Herbi- ? Carni- ? Omni- ? Hydro- ? Producers provide energy for other organisms in an ecosystem. Name three producers. : Producers provide energy for other organisms in an ecosystem. Name three producers. Producers get their energy from non-living resources. Producers are also called autotrophs because they make their own food. Producers provide energy for other organisms in an ecosystem. : Producers provide energy for other organisms in an ecosystem. These organisms are called Consumers because they get their energy by eating other living or once-living resources. Name 3 consumers. Consumers are also called heterotrophs. Almost all producers obtain energy from sunlight. If the producer doesn’t use sunlight, what might they use? : Almost all producers obtain energy from sunlight. If the producer doesn’t use sunlight, what might they use? Photosynthesis in most producers uses sunlight as an energy source. Chemosynthesis in prokaryote producers uses chemicals as an energy source. Slide 28: KEY CONCEPT Food chains and food webs model the flow of energy in an ecosystem. A food chain is a model that shows a sequence of feeding relationships. Why does “chain” fit this idea? : A food chain is a model that shows a sequence of feeding relationships. Why does “chain” fit this idea? A food chain follows the connection between one producer and a single chain of consumers within an ecosystem. Create your own food chain : Create your own food chain Beginning with a producer and including at least three organisms, give an example of a food chain. Slide 31: Consumers are not all alike. Herbivores eat only plants. Carnivores eat only animals. Omnivores eat both plants and animals. Detritivores eat dead organic matter. Decomposers are detritivores that break down organic matter into simpler compounds. Slide 32: Specialists are consumers that primarily eat one specific organism or a very small number of organisms. What other kinds of “specialists” do you know? Generalists are consumers that have a varying diet. Trophic levels are the nourishment levels in a food chain. : Trophic levels are the nourishment levels in a food chain. A food web shows a complex network of feeding relationships. : A food web shows a complex network of feeding relationships. An organism may have multiple feeding relationships in an ecosystem. Give an example. A food web emphasizes complicated feeding relationships and energy flow in an ecosystem. Slide 35: KEY CONCEPT Matter cycles in and out of an ecosystem Water Cycle Carbon Cycle Oxygen Cycle Phosphorus Cycle Nitrogen Cycle Hydrologic (Water) Cycle : Hydrologic (Water) Cycle The hydrologic, or water, cycle is the circular pathway of water on Earth. Organisms all have bodies made mostly of water. Carbon Cycle : Carbon is the building block of life. Why do we call it that? The carbon cycle moves carbon from the atmosphere, through the food web, and returns to the atmosphere. Carbon is emitted by the burning of fossil fuels. Some carbon is stored for long periods of time in areas called carbon sinks. Carbon Cycle Oxygen Cycle : Oxygen cycles indirectly through an ecosystem by the cycling of other nutrients. Oxygen Cycle Phosphorus Cycle : The phosphorus cycle takes place at and below ground level. Phosphate is released by the weathering of rocks. Phosphorus moves through the food web and returns to the soil duringdecomposition. Phosphorus leaches into groundwater from the soil and is locked in sediments. Both mining and agriculture add phosphorus into the environment. Phosphorus Cycle Nitrogen Cycle : The nitrogen cycle mostly takes place underground. Some bacteria convert gaseous nitrogen into ammonia through a process called nitrogen fixation. Some nitrogen-fixing bacteria live innodules on theroots of plants;others livefreely inthe soil. Nitrogen Cycle Slide 41: Nitrogen moves through the foodweb and returnsto the soil duringdecomposition. Slide 42: Quiz Answer Time! Quiz 14-2 Slide 43: 1. How do the activities of a keystone species affect the biodiversity of an ecosystem? A. They increase biodiversity. B. They decrease biodiversity. C. They have no effect on biodiversity. D. Biodiversity remains the same but the species change. Correct Answer = A 3. Which is a characteristic of an ecosystem in approximate equilibrium? A. The kinds of organisms do not change. B. Biotic factors do not change. C. Abiotic factors do not change. D. The total number of organisms do not change. Correct Answer = D Slide 44: 5. What is likely to occur in an ecosystem if all members of a keystone species die? A. Another species will become the keystone species. B. A keystone species from another ecosystem may take over. C. Most species in the ecosystem will be severely affected. D. The ecosystem will not change. Correct Answer = C 7. What term describes a consumer? A. heterotroph B. autotroph C. producer D. chemosynthetic Correct Answer = A Slide 45: 9. Where does most of the energy in an ecosystem originate? A. food B. sunlight C. chemicals D. organisms Correct Answer = B Review : Review Producers are organisms that can make their own energy from abiotic sources Consumers are organisms that must consume other organisms for energy. A food chain links organisms by their feeding relationships connecting a producer to a single line of consumers. A food web shows complicated feeding relationships Water, nitrogen, oxygen, phosphorous, and carbon all cycle through ecosystems.