TAMIL NADU AGRICULTURAL UNIVERSITY B.Sc (Agri./Seri.) Degree Programmes Final Theory Reappearance Examination, June - July 2015 Year Semester

:I (2011 Syllabus) Time : 2 ½ hrs :Max.Marks : 60 ENS 101 Principles of Environmental Sciences (1+1) PART-A (Answer All questions) [20 x 0.5 = 10] Choose the correct answer A1. The concept that communities proceed through a series of recognizable, predictable changes in structure over time is called -------------. a) Succession b) Ecological progress c) Biomagnification d) Ecological pyramid A2. The transit region between stratosphere and troposphere is known as a) Stratopause b) Tropopause c) Mesopause d) Ozonosphere A3. The hard outer region that includes the upper most mantle and all of the crust is called --------------. a) Lithosphere b) Asthenosphere c) Parent material d) Soil A4. Increase in concentration of chemicals through food chain from lower to the higher trophic levels is called as --------------. a) Biomagnification b) Bioaugumentation c) Bioaccumulation d) Bioventing A5. Algal bloom is associated with which element? a) Potassium b) Phosphorus c) Sulpher d) Calcium Fill in the blanks A6. The rate at which an ecosystem’s producer convert solar energy into chemical energy as biomass is the ecosystem’s ------------. A7. Cyclic movement of chemical elements of the biosphere between the organisms and the environment are referred to as ---------------. A8. -------------plays a critical role in leaf senescence, leaf abscission, epinasty and fruit ripening. A9. The deadliest skin cancer associated with ozone depletion is --------------. A10. The Bhopal disaster during 1984 was due to the release of--------------. Match the following A11. Lotic Dead organic matter A12. Lentic Water A13. Grazing food chain Standing water A14. Detritus food chain Green plants A15. Hydrosphere Running water State True or False A16. Ozone layer is present in stratosphere. A17. Greenhouse gases play a major role in maintaining the heat balance of the earth as it absorbs infrared radiation. A18. Hydrosphere and biosphere together constitute biome environment. A19. The optimum C/N ratio required for biogas generation is 30:1. A20. “Gray - air - smoke” is associated with CO gas.

ENS 101 Principles of Environmental Science -2PART - B (Answer any Ten questions only)

[10x1=10]

B1. Eutrophication. B2. Biomagnification. B3. Biodiversity. B4. Ecological niche. B5. Acid rain. B6. Kyoto protocol. B7. Define ecosystem. B8. Photochemical smog. B9. Global warming. B10. Keystone species. B11 .Biosphere. B12. Expand IPCC and UNEP. PART-C (Answer any Ten questions only) [10 x 2 = 20] C1. Classification of air pollutants with examples. C2. Differentiate between food chain and food web. C3. Greenhouse effect. C4. List out major causes of biodiversity. C5. Describe the structure of atmosphere. C6. Differentiate between pollutant and contaminant. C7. Ecological pyramids. C8. Soil pollution. C9. Writ a short note on CDM. C10. List the importance of forest resources. C11. Sources of water pollution. C12. Environmental education. PART-D (Answer any Five questions only) [5 x 4 = 20] D1. Distinguish between the abiotic and biotic components of ecosystems and give three examples of each. D2. Describe the characterization of solid wastes. What are methods available for solid waste management? D3. What are the concepts and conservation measures of biodiversity? D4. What are green house gases? Discuss their relative contribution to global warming. D5. Describe various nutrient cycles involved in a typical agricultural ecosystem. D6. What are the sources and classification of major air pollutants? Discuss the effect of air pollution on crop, animal and human. D7. What is acid rain? Write about the photochemical reaction in the atmosphere leading to acidic precipitation and its environmental impacts. ---------x--------