Big on Biology

1. Big on Biology Who’s Got the Energy? 9-12 Science Std: Bio 6f

2. Pyramids of Mass and Energy • Already know that abiotic (nonliving) factors are just as important to ecosystem as biotic (living) factors • One of most important abiotic factors is energy, which ties together organisms in ecosystem =

3. Energy: ability of organism to do work; power (measured in Joules or J) • Energy enters ecosystem in the form of sunlight Entire ecosystem starts with sunlight

4. Producers (plants, phytoplankton, bacteria) absorb the energy from sunlight to produce their own food • Herbivores eat the producers to get their energy • Carnivores eat the herbivores to get their energy • Higher order carnivores eat lower order carnivores to get their energy

5. Size of community is limited by the amount of energy entering system through its producers, so the amount obtained from photosynthesis is all energy available 100% Energy Available

6. Relationships about energy and its transfer from organism to organism is called thermodynamics and exists in two laws: • First Law of Thermodynamics • Second Law of Thermodynamics

7. First Law of Thermodynamics: energy can neither be created nor destroyed, just transformed • Plants get energy from sun, herbivores get energy from plants ENERGY

8. Second Law of Thermodynamics: in any transformation of energy, some energy will be lost and unusable • Transfer from plant producers to animal herbivores will lose energy that can’t be recaptured ENERGY LOST ENERGY TO COW

9. Energy lost is usually in form of heat • Energy lost from chain “link” to “link” is significant! • from grass to cow, loss is about 90%! HEAT 90% HEAT 90% 100% Energy Available 10% Original Energy! 1% Original Energy!

10. Energy lost from one trophic level (energy level) to the next level can be represented by a pyramid 4 CONSUMERS 3 CONSUMERS 2 CONSUMERS 1 CONSUMERS PRODUCERS

11. Pyramid of Mass/Energy: A picture showing the amount of energy available at each trophic level • Each level above only gets 10% of the energy from below • Ex: 10,000 J of producers (plants) only give 10% of energy to primary consumers • 1,000 J to primary consumers (snails, minnows, dragonflies) • 100 J to secondary consumers (small fish) • 10 J to tertiary consumers (big fish) • 1 J to quaternary consumers (fish hawk)

12. ENERGY PYRAMID 1 J 10 J 100 J 1,000 J 10,000 J

13. ENERGY PYRAMIDS

14. ENERGY PYRAMIDS

15. The top of the pyramid is smaller than the bottom to show that some energy is lost as it moves through each level of the food web (chain) • Usually no more than 5 trophic levels since 6th level would have very little energy to keep it alive

16. A horse requires about 18,000 calories in its daily diet • A little practice……..(round 1) • How many calories are released to the environment as heat? • 90% of the energy is lost so….. • Energy lost = 18,000 cal x 90% • Energy lost = 18,000 x 0.9 • Energy lost = 16,200 calories!

17. Recommend daily calorie intake for humans is 2000 cal. If humans are 2° Consumers, how much energy must come in to the producers to support us? • A little practice……..(round 2) • Only 10% of energy in transfers to the next level • Each lower trophic level gets 10x more energy in than the level above

18. If we are 2nd level consumer – primary consumers get 10x more energy than us. • A little practice……..(round 2) • 1° Energy = 10 x 2° Energy = 20,000 cal • Prod Energy = 10 x 1° Energy • = 200,000 cal energy in • It would take and area of producers equal to 20 tables for each person to survive

19. Questions?