Concept 1.2: Energy Flow in the Ecosystem (PDF)

Concept 1.2 L1.energy flow in the ecosystem Ecosystem: It is an area (or community) that includes living organisms and non- living things that interact with each other. Living organisms as: plants, animals and humans. Non-living things as: air soil and water. Ex of eco...

Concept 1.2 L1.energy flow in the ecosystem Ecosystem: It is an area (or community) that includes living organisms and non- living things that interact with each other. Living organisms as: plants, animals and humans. Non-living things as: air soil and water. Ex of ecosystem as: ocean, rainforest, desert, tundra or sea. Ecosystems provides Food, water and shelter. This interaction depends on the flow of energy between them. Energy flows through an ecosystem from plants to animals and between animals when they eat each other. When living organisms die, their energy is returned to the soil.  How hawks get energy. Hawks get energy from eating animals such as: - 1. Snakes 2. Mice 3. Fish 4. Birds 5. Squirrels 6. Rabbits and other small ground animals. Hawks don’t eat plants; they depend on plants for energy. G.R? - Because they eat animals who eat plants.  Predators that can attack hawks: - Few predators such as eagles or other hawks.  When the hawk dies, it decomposes, and the energy returns to soil.  What do animals eat? Examples: 1. Rabbit eats 2.Caracal eats 3.Bird eats 4.Lion eats deer. grass. rabbits and mice worms. Plants Animals and humans Can make their own food Cannot make their own food. - Use sunlight energy to - Get their food from: - convert water and carbon 1. Eating plants only. dioxide into glucose. 2. Eating animals only. (photosynthesis) 3. Eating both plants and animals.  There is a relationship between sunlight and the energy we get from our food, because the energy we get from food comes from the sun. L.2 Food is energy  We get energy from food and oxygen. We need energy to: - 1- Do activities (running – walking and talking). 2- To do internal function (heart beats and thinking) even when we sleep.  Some activities require a lot of energy (hard work and physical exercise)  The sun is the primary Sun energy transfered to source of energy for living, growing and carrying out Plants life processes. Animals and humans  Food chain Living organisms are classified into three groups according to their way of feeding, which are: 1.Producers. 2.Consumers. 3.Decomposers. Producers: They are organisms that can make their own food and don’t feed on other organisms. Example: plants. Nearly all the producers on the earth are plants.  Consumers: They are organisms that can’t make their own food and eat other living organisms to get energy. Examples: - Primary consumers Secondary consumers Tertiary consumers Animals that eat Eat primary Eat secondary plants. consumers. consumers. Like many insects Like birds. -They are large meat-eating animals. -Like crocodiles. Decomposers: They are organisms that responsible for breaking down or decaying dead organisms through decomposition process. Examples of decomposers: 1.Fungi 2. Bacteria 3. Worms 4. Millipedes. Millipedes and worms increase the fertility for plant growth. G.R? - Because they produce waste rich in nutrients. L3. Food chain It is a Model that shows energy transfer from one organism to another in the ecosystem. Or It is a model that shows a linear set of feeding relationships and movement of energy between living organisms.  From the previous food chain: 1- First link is plant (producer) (can make its food). 2- Second link is mouse (primary consumer) (it eats plants) 3- Third link is snake (secondary consumer) (eats primary consumer) 4- Eagle is tertiary consumer because it eats snake. 5- Finally, when the Eagle dies it decomposes and its energy returns to the soil which help plant to grow. Food relationship = energy relationship. 6- The energy passes from the sun to plants, then to mouse and snake then finally to eagle. Predator: any animal that hunts and eats another animal. Prey: any animal that is hunted and eaten by another animal. Both predator and prey pass food and energy through the food chain.  Give reason: - Some living organisms get their energy by eating another living organism.GR Because they cannot get energy directly from the sun.  Food web It is a model that shows several interconnected food chains among living organisms. Or It is a model that show many different feeding relations between living organisms. Food chains interact within ecosystem to form (food web) Food web is used to show how the organisms that live in the same ecosystem depend on each other for survival. In Food web Several different consumers may eat the same producer or prey. It is better to use a food web to show interactions among living organisms. G.R? Because the food web contains many organisms, while a food chain contains just a few organisms. Food web will be affected if an organism disappears. G.R? - Because some organisms will lose their food source. We can observe that: - 1. Both grasshoppers, rabbit and mouse eat plants. 2. Fox eats mouse and rabbit. 3. Hawk eats rabbit, fox and mouse.