Lesson 3

Lesson 3Energy in EcosystemsKey Concepts/essential questions:

How does energy move in ecosystems?

How is the movement of energy in an ecosystem modeled?VocabPhotosynthesisChemosynthesisFood chainFood webEnergy pyramid

Agree OR DisagreeThe sun is the source for all energy used by living things on Earth?

All living things get their energy from eating other living things?How does the grass get the energy it needs?The grass gets energy from sunlight and performs photosynthesis.

ProducersWhat powers the process of photosynthesis?Light energy, usually from the Sun, powers photosynthesis.WORD ORIGIN: photosynthesis

What words do you know that begin with photo?root -graph means "writeWhat is the meaning of photograph?A photograph is an image created using light energyHow does light relate to photosynthesis?The energy from light powers the processes that create food through photosynthesis.

chemosynthesis What other words begin with chemo-?Chemotherapy???What is the meaning of the word chemotherapy?medical treatment with chemicalslook up the word chemotherapy in a dictionary to find the meaning of the root chemo-.look up the word synthesis.synthesis means "to put together" or "to build.Chemosynthesis: to build, using chemicals What is the role of chemicals in chemosynthesis? They provide chemical energy. What is being built?food moleculesWhat materials do producers use to make food during chemosynthesis?Producers use chemical energy in inorganic compounds to make food during chemosynthesis.

Look at Figure 10 in text on pg. 724. What does the arrow tell you about where the plant gets carbon dioxide for photosynthesis? Carbon dioxide enters the leaf directly from the atmosphereWhat does the arrow tell you about where the plant gets water for photosynthesis?The water travels into the leaf from other parts of the plant (roots).Lesson 3: Energy in Ecosystems-notesA. How does energy move in ecosystems?1. Matter cycles through an ecosystem.2. Energy flows through an ecosystem.3. Energy can change form as it moves through an ecosystem, but the total amount of energy stays the same. This rule is called the law of conservation of energy.3Energy in EcosystemsLESSON4. Organisms that make their own food are producers.a. The process of photosynthesis uses light energy to make food and oxygen from carbon dioxide and water.b. Chemosynthesis is the process of making food using chemical energy instead of light energy.

LESSON5. Consumers obtain energy by eating other organisms.a. A(n) herbivore eats only plants.b. Carnivores are animals that eat other animals.c. Omnivores eat producers and other consumers.d. Consumers called detrivores (scavengers) eat dead organisms.e. Another name for bacteria and mushrooms is decomposers.f. Decomposers help cycle nutrients through ecosystems.

LESSONB. Modeling Energy in Ecosystems1. As energy changes from one organism to another in an ecosystem, some storedchemical energy changes to thermal energy.2. A(n) food chain is a model that shows how energy flows in an ecosystem through feeding relationships.

LESSONC. Food Webs1. When you overlap the food chains in an ecosystem, the result is a(n) food web.2. In a food chain and a food web, arrows show the movement of energy.

LESSOND. Energy Pyramids1. A(n) energy pyramid shows the amount of energy available in each step of a foodchain.2. The steps of this energy model are called trophic levels.a. The bottom layer of an energy pyramid contains producers.b. The middle layer of an energy pyramid contains consumers that eat producers.

LESSONc. The top layer of an energy pyramid contains consumers that eat other consumers.3. Only about 10 percent of the energy in one step of an energy pyramid transfers to the next higher step.

LESSONBrainpophttp://connected.mcgraw-hill.com/media/repository/protected_content/COMPOUND/50000025/8/27/Photosynthesis_and_Respiration/00053412.htm?mghCourseID=J3B3WWJLT82D2DYG587957LKB4

ConsumersLook at figure 12.How does the worm get energy?It gets energy by consuming the remains of other animals and plants.How does the worm help the environment?By decomposing dead organisms, the worm helps keep the environment cleanFood ChainsLook at figure 13.What is a feeding relationship?It is an interaction between two organisms where one organism eats the other.Draw a food chainShare answers (discuss feeding relationship)

How does a food chain model energy flow?Arrows in a food chain show how energy is transferred from one organism to another through a feeding relationship.In terms of school and scienceWhat is a model?A model is a way of describing or showing an observation or process.

Food chainarrows that indicate the transfer of energy.What does the arrow below the hawk tell you about the energy transfer?Energy is transferred to the hawk when it eats another organism (snake)

Why is there no arrow pointing away from the hawk?Because there is no organism shown that eats the hawkVideo cliphttp://connected.mcgraw-hill.com/c2j/syllabus.syllabusLesson.do?bookId=J3B3WWJLT82D2DYG587957LKB4&lessonId=7EOP91DMCXOL51SX6CP8JQP4QY

(video 1)Food WebsLook at Figure 14.Try to make as many food chains using this web as you can

Video cliphttp://connected.mcgraw-hill.com/c2j/syllabus.syllabusLesson.do?bookId=J3B3WWJLT82D2DYG587957LKB4&lessonId=7EOP91DMCXOL51SX6CP8JQP4QY

(video 2)What models show the transfer of energy in an ecosystem?The transfer of energy in an ecosystem is shown with food chains and food webs.

What kind of organism must be at the bottom of a food web? Why?A producer must be at the bottom of a food web because energy must flow into the food web from an outside source, such as the Sun.Food Web

Is the portion of the food web shown below a complete food chain? Explain. Yes, it includes producers(diatoms) and consumers.Do any organisms pictured in the portion of Figure 14 below get energy from the leopard seal?NoIf the leopard seal has no predators in a given area, do any organisms get energy from it? Yes, decomposers get energy from the leopard seal.Energy Pyramids

How does the amount of available energy change at each trophic level?The amount of available energy decreases at each trophic level.Which trophic level contains the fewest organisms? Why?Trophic level 3 contains the fewest organisms because it has the least energy available.What kind of organism is in trophic level 1? Trophic level 1 contains producers that get energy from an outside source, usually the Sun.*note fading blue arrow*Video cliphttp://connected.mcgraw-hill.com/c2j/syllabus.syllabusLesson.do?bookId=J3B3WWJLT82D2DYG587957LKB4&lessonId=7EOP91DMCXOL51SX6CP8JQP4QY

(video 3)QuestionsWhat is an example of a producer in the trophic level at the bottom of the pyramid?PlantsCan carnivores occupy trophic level 1? Explain.No, carnivores get energy by eating meat. The only available energy in trophic level 1 comes from the Sun.

DiscussionWhat did you have for dinner last night?Use an energy pyramid to trace the flow of energy from the Sun to each kind of food.Agree OR DisagreeThe sun is the source for all energy used by living things on Earth?Disagree. The sun in the main source of energy for most life on Earth; some producers, deep in the ocean, use chemical energy rather than light energy.

Agree OR DisagreeAll living things get their energy from eating other living things?Disagree. Many organisms get their energy by eating other organisms; some organisms are producers and get their energy through the process of chemosynthesis or photosynthesis to make their food.

Key Concepts/essential questions: How does energy move in ecosystems?Energy moves in a flow, How is the movement of energy in an ecosystem modeled?Arrows in a food chain show how energy is transferred from one organism to another through a feeding relationship. (food chain, food web, energy pyramid)Discussion QuestionHow does energy flow through an ecosystem?

LESSONEnergy flow begins with energy in sunlight. It is stored as chemical energy in plants. Asanimals eat plants, energy moves from the plant to the animal. As animals eat otheranimals, energy flows from the animal being eaten to the animal eating it. During each ofthese steps, energy can change form, such as changing from chemical to thermal energy.

LESSON