13.3 Energy in Ecosystems TEKS 11C, 12C

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1 13.3 Energy in Ecosystems TEKS 11C, 12C The student is expected to: 11C summarize the role of microorganisms in both maintaining and disrupting the health of both organisms and ecosystems and 12C analyze the flow of matter and energy through trophic levels using various models, including food chains, food webs, and ecological pyramids

2 13.3 Energy in Ecosystems TEKS 11C, 12C KEY CONCEPT Life in an ecosystem requires a source of energy.

3 13.3 Energy in Ecosystems TEKS 11C, 12C Producers provide energy for other organisms in an ecosystem. Producers get their energy from non-living resources. Producers are also called autotrophs because they make their own food.

4 13.3 Energy in Ecosystems TEKS 11C, 12C Producers provide energy for other organisms in an ecosystem. Consumers are organisms that get their energy by eating other living or once-living resources. Consumers are also called heterotrophs because they feed off of different things.

5 13.3 Energy in Ecosystems TEKS 11C, 12C Almost all producers obtain energy from sunlight. Photosynthesis in most producers uses sunlight as an energy source. Chemosynthesis in prokaryote producers uses chemicals as an energy source. carbon dioxide + water + hydrogen sulfide + oxygen sugar + sulfuric acid

6 13.4 Food Chains And Food Webs TEKS 11C, 12,C The student is expected to: 11C summarize the role of microorganisms in both maintaining and disrupting the health of both organisms and ecosystems and 12C analyze the flow of matter and energy through trophic levels using various models, including food chains, food webs, and ecological pyramids

7 13.4 Food Chains And Food Webs TEKS 11C, 12,C KEY CONCEPT Food chains and food webs model the flow of energy in an ecosystem.

8 13.4 Food Chains And Food Webs TEKS 11C, 12,C A food chain is a model that shows a sequence of feeding relationships. A food chain links species by their feeding relationships. A food chain follows the connection between one producer and a single chain of consumers within an ecosystem. GRAMA GRASS DESERT COTTONTAIL HARRIS S HAWK

9 13.4 Food Chains And Food Webs TEKS 11C, 12,C 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. carnivore decomposer

10 13.4 Food Chains And Food Webs TEKS 11C, 12,C Specialists are consumers that primarily eat one specific organism or a very small number of organisms. Generalists are consumers that have a varying diet.

11 13.4 Food Chains And Food Webs TEKS 11C, 12,C Trophic levels are the nourishment levels in a food chain. Primary consumers are herbivores that eat producers. Secondary consumers are carnivores that eat herbivores. Tertiary consumers are carnivores that eat secondary consumers. Omnivores, such as humans that eat both plants and animals, may be listed at different trophic levels in different food chains.

12 13.4 Food Chains And Food Webs TEKS 11C, 12,C A food web shows a complex network of feeding relationships. An organism may have multiple feeding relationships in an ecosystem. A food web emphasizes complicated feeding relationships and energy flow in an ecosystem.

13 13.4 Food Chains And Food Webs TEKS 11C, 12,C What is the significance of arrows in a food chain? They show the direction of the energy flow producer consumer 1 consumer 2 consumer 3

14 13.4 Food Chains And Food Webs TEKS 11C, 12,C If all of the snakes in this chain died, what would happen to the hawk? They would have to find a new food supply, such as the mouse or they would not be able to survive decomposer producer consumer 1 consumer 2 consumer 3

15 13.4 Food Chains And Food Webs TEKS 11C, 12,C If all of the mice in this chain died, what would happen to the web? The web would become unsustainable as a vital part of it would be missing. decomposer producer consumer 1 consumer 2 consumer 3

16 Ecological Pyramids

17 Ecological Pyramids Instead of representing trophic levels in a food web, an ecological pyramid can be used Hawk (1 kcal) Snake (10 kcal) Frog (100 kcal) Grasshopper (1,000 kcal) Grass (10,000 kcal)

18 Ecological Pyramids Does this pyramid represent a food chain or web? A chain, because there is only one organism at each level Hawk (1 kcal) Snake (10 kcal) Frog (100 kcal) Grasshopper (1,000 kcal) 1 Grass (10,000 kcal)

19 Pyramid of Energy Pyramids of energy show the relative amount of energy available at each trophic level of a food chain or food web. kcal = kilocalories Hawk (1 kcal) Snake (10 kcal) Frog (100 kcal) 2 Grasshopper (1,000 kcal) 1 Grass (10,000 kcal)

20 Pyramid of Energy What happens to the energy as you go up the pyramid? It decreases as it is either lost as heat energy or used in metabolism 5 Hawk (1 kcal) Only about 10 percent of energy is passed on to the next trophic level Snake (10 kcal) Frog (100 kcal) Grasshopper (1,000 kcal) 1 Grass (10,000 kcal)

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22 Pyramid of Biomass Pyramid of Biomass - represents the relative amount of living organic matter available at each trophic level

23 Pyramids of Numbers show the relative number of individual organisms at each trophic level. Pyramid of Numbers

24 Ecological Pyramids Correctly label each pyramid shown at the top of the pyramid section.