1. Ecology

2. Basic Concepts Species : a group of organism that can interbreed & produce fertile offspring.(have a common gene pool). Habitat: the environment in which species normally lives (location). Population: a group of the organism of the same species,living in the same area at the same time. Community: a group of populations living & interacting with each other in an area. Ecology: the study of relationships between living organisms & their environment. 2 Amit Mishra - NES International School Mumbai

3. Environment Its everything which surrounds an organism. It has 4 main components Hydrosphere (water) Atmosphere (gases) Lithosphere (rocks) Biosphere (all living beings) The first 3 are abiotic components while the 4 th is the Biotic component 3 Amit Mishra - NES International School Mumbai

4. Autotrophs & heterotrophs 4 Amit Mishra - NES International School Mumbai

5. Autotrophs are the organisms with the capacity to make their own food. Eg.:cynobacteria, Algae,Grass, Trees. Hetrotrophs are the organisms which do not have the capacity to produce their own food. Eg.:animals,fish,zooplanktons. Three types : consumers detritivore saprotroph 5 Amit Mishra - NES International School Mumbai

6. Detrivores & saprotrophs Detrivores are the organism that consumes dead organic matter. Eg.: earthworm, woodlice. Saprotrophs are the organisms that live on, or in, dead organic matter. (digesting the food by secreting enzymes). 6 Amit Mishra - NES International School Mumbai

7. Food chain & food web 7 Amit Mishra - NES International School Mumbai

8. A food chain is a sequence of relationships between trophic levels where each member feeds on the previous one. A food web is a diagram that shows the feeding relationships in a community. The arrows indicate the direction of energy flow. It’s the interlinking of the food chains. 8 Amit Mishra - NES International School Mumbai

9. Define trophic level. (1) A trophic level is where an organism is positioned on a food web. Producer Primary consumer Secondary consumer Tertiary consumer 9 Amit Mishra - NES International School Mumbai

10. Sun is the principal source of energy in biological systems. Green plants absorb only a very small fraction of (about 10%) of the light energy. Light energy converts into chemical energy by plants. 10 Amit Mishra - NES International School Mumbai

11. 10 % Law of energy flow Of the total energy entering a particular trophic level, only 10% is available for the next higher trophic level. Grass → Goat → Tiger 200 Kg → 20Kg → 2Kg Hence short food chains provide more energy to higher trophic level. That’s the reason why vegetarians get more energy than meat eating people. 11 Amit Mishra - NES International School Mumbai

12. Ecological pyramids Pyramid of biomass Biomass is the total dry mass of all organism in an unit area. Total biomass = biomass of producers + biomass of consumers + biomass of decomposers. The mass of all the organisms at each step of the food chain is measured. On the basis of the measurement of the dry mass (at each trophic level) a diagram can be drawn. This is known as pyramid of Biomass. 12 Amit Mishra - NES International School Mumbai

13. Pyramid of Number This is drawn according to the number of organisms at each trophic level of the food chain. 13 Amit Mishra - NES International School Mumbai

14. Pyramid Of Energy Energy pyramids are formed by measuring the amount of energy available at each trophic level in the food chain. The energy is measured over a fixed period of time. 14 Amit Mishra - NES International School Mumbai

15. Pyramid of Energy 15 Amit Mishra - NES International School Mumbai

16. Explain that energy can enter and leave an ecosystem, but that nutrients must be recycled. Energy enters as light and usually leaves as heat. Nutrients do not usually enter an ecosystem and must be used again and again. Nutrients such as Carbon dioxide, Nitrogen, and Phosphorus 16 Amit Mishra - NES International School Mumbai

17. Greenhouse Effect Phenomenon The mean global temperature has risen about 1 degree Celsius since 1856. We saw an increase between 1910 and 1940, and from 1970 onwards. 17 Amit Mishra - NES International School Mumbai

18. Greenhouse Effect Human Activities Increased burning of fossil fuels releasing Greenhouse gases Deforestation – less trees to convert CO 2 back to O 2 Other industrial activities that release other Greenhouse gases 18 Amit Mishra - NES International School Mumbai

19. Greenhouse Effect Causes Light from the sun has short wavelengths and can pass through most of the atmosphere. This sunlight warms the earth which in turn emits long wave radiation. This long wave radiation is bounced back by the greenhouse gases, such as carbon dioxide, methane, water vapour, and sulphur dioxide 19 Amit Mishra - NES International School Mumbai

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21. Greenhouse Effect Flooding of low –lying land Melting of glaciers and polar ice More frequent storms and hurricanes Changes in weather patterns 21 Amit Mishra - NES International School Mumbai

22. Greenhouse Effect Measures Increase photosynthesis and reduce emissions by: restoring ecosystems where there has been deforestation or desertification spreading nutrients such as iron in nutrient- deficient oceans to encourage algal growth 22 Amit Mishra - NES International School Mumbai

23. Greenhouse Effect Reducing energy consumption; insulation, smaller vehicles, local grown food instead of transported Changing from fossil fuels to solar, wind, or nuclear 23 Amit Mishra - NES International School Mumbai

24. Carbon cycle The carbon cycle includes the interaction of living organisms and the biosphere through the processes of photosynthesis, respiration, fossilization and combustion. 24 Amit Mishra - NES International School Mumbai

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26. Populations Outline how population size can be affected by natality, immigration, mortality and emigration. 26 Amit Mishra - NES International School Mumbai

27. Populations Natality – offspring are produced and added to the population Mortality – individuals die and are lost from the population Immigration – individuals move into the area from somewhere else and add to the population Emigration – indivuals move out of the area and are lost from the population 27 Amit Mishra - NES International School Mumbai

28. Populations Draw a graph showing the sigmoid (S- shaped) population growth curve.(1) 28 Amit Mishra - NES International School Mumbai

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30. Populations Lag phase: population just begins to grow Exponential Phase Population increases exponentially because the natality rate is higher than the mortality rate. This is because there is an abundance of food, and disease and predators are rare. 30 Amit Mishra - NES International School Mumbai

31. Populations Transitional Phase Difference between natality and mortality rates are not as great, but natality is still higher so population continues to grow, but at a slower rate. Food is no longer as abundant due to the increase in the population size. May also be increase predation and disease. 31 Amit Mishra - NES International School Mumbai

32. Populations Plateau Phase Natality and mortality are equal so the population size stays constant. Limiting Factors: shortage of food or other resources increase in predators more diseases or parasites If a population is limited, then it has reached its carrying capacity 32 Amit Mishra - NES International School Mumbai

33. Populations Define carrying capacity. The maximum population size that can be supported by the environment 33 Amit Mishra - NES International School Mumbai

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35. Populations List three factors which set limits to population increase. Limiting Factors: shortage of food or other resources increase in predators more diseases or parasites 35 Amit Mishra - NES International School Mumbai