ECOLOGY AND ENVIRONMENTAL SCIENCE (2023) FYUG Odd Semester Exam | EESIDC-101T

Subject: Basic Concepts of Ecology and Environmental Science

Programme: FYUG (1st Semester)

Paper Code: EESIDC-101T

Full Marks: 70 | Pass Marks: 28

Time Duration: 3 Hours

Instructions: Figures in the margin indicate full marks. Answer sections as per unit-wise selection.

Section-A (1 Mark Each)

Answer twenty questions, selecting any four from each Unit.

UNIT-I

1. Who coined the term 'ecology'?
Ernst Haeckel coined the term 'ecology' in 1866.

2. Define environmental science.

Environmental science is an interdisciplinary field that integrates physical, biological, and information sciences to study the environment and find solutions to environmental problems.

3. Who developed the concept of 'food chain'?
The concept of the food chain was first introduced by the Arab scientist and philosopher Al-Jahiz and later popularized by Charles Elton.

4. State one difference between ecology and environmental science.
Ecology focuses specifically on the interactions between organisms and their environment, while environmental science is a broader field that incorporates social, political, and chemical aspects of human impact on the world.

5. Mention the different types of food chain.
The two main types are the Grazing food chain and the Detritus food chain.

UNIT-II

6. What is an ecosystem?
An ecosystem is a structural and functional unit of the biosphere consisting of a community of living organisms interacting with their non-living physical environment.

7. What are the different components of an ecosystem?
The components are categorized into Biotic components (living beings) and Abiotic components (physical factors like sunlight, temperature, and minerals).

8. What is population?
A population is a group of individuals of the same species living in a specific geographical area at a particular time.

9. Define biosphere.
The biosphere is the narrow zone of the Earth where land, water, and air interact to support life.

10. What is species?
A species is a group of organisms that share common characteristics and are capable of interbreeding to produce fertile offspring.

UNIT-III

11. What is atmosphere?
The atmosphere is the thick gaseous envelope surrounding the Earth, held in place by gravity.

12. Mention the different layers of atmosphere.
The layers are: Troposphere, Stratosphere, Mesosphere, Thermosphere, and Exosphere.

13. What is the percentage of oxygen in the atmosphere?
Oxygen accounts for approximately 21% of the Earth's atmosphere.

14. What is monsoon?
Monsoon refers to the seasonal reversal in wind direction, often associated with significant changes in precipitation.

15. What is atmospheric pressure?
Atmospheric pressure is the force exerted by the weight of the air above a given point on the Earth's surface.

UNIT-IV

16. What is hydrosphere?
The hydrosphere includes all the water found on, under, and above the surface of the Earth, including oceans, lakes, rivers, and groundwater.

17. Define freshwater.
Freshwater is naturally occurring water containing low concentrations of dissolved salts and other total dissolved solids (usually less than 0.5 parts per thousand).

18. Give two examples of lentic ecosystem.
Examples include Ponds and Lakes.

19. What is an estuary?
An estuary is a partially enclosed coastal body of brackish water where freshwater from rivers meets and mixes with saltwater from the ocean.

20. What is groundwater?
Groundwater is the water found underground in the cracks and spaces in soil, sand, and rock, stored in and moving slowly through geologic formations called aquifers.

UNIT-V

21. What is lithosphere?
The lithosphere is the rigid, outermost shell of the Earth, comprising the crust and the portion of the upper mantle that behaves elastically.

22. What is soil profile?
A soil profile is a vertical cross-section of the soil that exposes its various layers or horizons.

23. What is mantle?
The mantle is the layer of the Earth located between the crust and the outer core, consisting of hot, semi-solid silicate rocks.

24. What is humus?
Humus is the dark, organic material in soil formed by the decomposition of plant and animal matter by microorganisms.

25. Mention the composition of core.
The Earth's core is primarily composed of Iron (Fe) and Nickel (Ni).

Section-B (2 Marks Each)

Answer five questions, selecting one from each Unit.

UNIT-I

26. Mention any two objectives of studying ecology.

  • To understand the functional relationships between organisms and their environments.
  • To provide a scientific basis for the conservation of biodiversity and sustainable management of natural resources.

27. Mention any two approaches of studying ecology.

  • Autecology: The study of individual species in relation to their environment.
  • Synecology: The study of groups of organisms (communities) in relation to their environment.

UNIT-II

28. Mention the difference between food chain and food web. Give at least one example.

Feature Food Chain Food Web
Definition A linear sequence of organisms. A complex network of interconnected food chains.
Example Grass -> Goat -> Lion A forest network where a hawk may eat a mouse, bird, or snake.

29. What is the difference between population and community? Give at least one example.
A Population consists of individuals of a single species in a specific area (e.g., all the tigers in a forest). A Community consists of all the different populations of various species interacting in that same area (e.g., tigers, deer, grass, and trees in a forest).

UNIT-III

30. Give two characteristic features of stratospheric ozone.

31. What is the difference between weather and climate?
Weather refers to the short-term state of the atmosphere (minutes to days) in a specific place. Climate is the long-term average of weather patterns in a region over a minimum of 30 years.

UNIT-IV

32. What are the differences between marine and estuarine system?
Marine systems have high and constant salinity (approx. 35 ppt) and are vast, open bodies of water. Estuarine systems have fluctuating salinity (brackish) because they are transition zones where river freshwater meets the sea.

33. What are the differences in the characteristics of lotic and lentic system?
Lotic systems involve flowing water (e.g., rivers, streams), whereas Lentic systems involve still or standing water (e.g., ponds, lakes).

UNIT-V

34. Give two importances of lithosphere.

35. Give any two importances of water holding capacity of soil.

Section-C (8 Marks Each)

Answer five questions, selecting one from each Unit.

UNIT-I

36. Elaborate on the multidisciplinary nature of the subject Ecology and Environmental Science.
Ecology and Environmental Science are inherently multidisciplinary because they draw from various branches of knowledge to address complex environmental issues.

  • Biological Sciences: Concepts from Botany, Zoology, and Microbiology are used to understand species interactions.
  • Physical Sciences: Physics and Chemistry help explain energy flow, chemical cycles, and pollutant behavior.
  • Earth Sciences: Geology and Hydrology provide context for soil formation and water distribution.
  • Social Sciences: Economics, Sociology, and Law are essential for creating environmental policies and understanding human-nature relationships.
This integration is necessary because an environmental problem (like climate change) cannot be solved by one discipline alone; it requires scientific understanding, economic assessment, and legal regulation.

37. Discuss elaborately the need for environmental awareness.
Environmental awareness is the first step toward conservation.

  • Resource Depletion: With the growing population, natural resources are being used at an unsustainable rate. Awareness helps promote "Reduce, Reuse, Recycle."
  • Pollution Control: Understanding the sources of air, water, and soil pollution encourages communities to adopt cleaner practices.
  • Health Protection: Many diseases are linked to environmental degradation. Awareness helps people understand the link between a clean environment and personal health.
  • Sustainable Development: Awareness ensures that current development does not compromise the ability of future generations to meet their needs.

UNIT-II

38. Describe with suitable examples the energy flow in an ecosystem.
Energy flow is the transfer of energy from the sun through various trophic levels of an ecosystem. It follows the Laws of Thermodynamics.

Example: Sun -> Grass (10,000 J) -> Deer (1,000 J) -> Tiger (100 J).

39. What is biogeochemical cycle? Describe the nitrogen cycle with suitable diagrammatic illustration.

A biogeochemical cycle is the movement of chemical elements and compounds between living organisms and the physical environment.
Nitrogen Cycle Steps:
  1. Nitrogen Fixation: Conversion of N2 gas into ammonia (NH3) by bacteria like Rhizobium.
  2. Nitrification: Ammonia is converted to nitrites and then nitrates.
  3. Assimilation: Plants absorb nitrates to build proteins.
  4. Ammonification: Decomposers convert organic nitrogen from dead matter back into ammonia.
  5. Denitrification: Bacteria convert nitrates back into N2 gas.

UNIT-III

40. Discuss briefly the climate of NE India.
The climate of Northeast India is characterized by:

  • High Rainfall: It receives some of the highest rainfall in the world (e.g., Mawsynram).
  • Humid Subtropical Climate: Summers are hot and humid, while winters are mild.
  • Monsoon Dominance: The Southwest Monsoon (June-September) is the primary source of rain.
  • Physiographic Influence: The Himalayas and local hills significantly influence local wind patterns and rain-shadow areas.

41. Discuss the tropical monsoon climate.
The Tropical Monsoon climate (Am in Köppen classification) is marked by:

  • Seasonal Wind Reversal: Onshore winds in summer and offshore winds in winter.
  • Distinct Wet and Dry Seasons: Most precipitation occurs during the high-sun season.
  • Temperature: High temperatures throughout the year, usually above 18°C.
  • Vegetation: Supports lush tropical deciduous forests.

UNIT-IV

42. Describe briefly, with suitable diagrammatic illustration, the hydrologic cycle.
The hydrologic cycle is the continuous movement of water on, above, and below the surface of the Earth.

43. Describe briefly the various physical, chemical and biological pollutants that affect our surface water.

  • Physical Pollutants: Suspended solids, silt from erosion, and thermal pollution (hot water from industries).
  • Chemical Pollutants: Heavy metals (Lead, Mercury), pesticides, fertilizers (causing eutrophication), and industrial solvents.
  • Biological Pollutants: Pathogenic bacteria, viruses, and protozoa from untreated sewage and animal waste.

UNIT-V

44. What is soil? Write notes on the composition of soil and formation of soil.
Soil is the thin layer of loose material on the Earth's surface that supports plant life.
Composition of Soil:

Formation of Soil (Pedogenesis): It involves the weathering of parent rock through physical, chemical, and biological processes, influenced by climate, organisms, topography, and time.

45. Describe the physical properties of soil and the role played by such properties in soil ecosystem.

Role: These properties determine which plants can grow, the rate of decomposition, and the habitat quality for soil organisms like earthworms and bacteria.