ECOLOGY AND ENVIRONMENTAL SCIENCE (2025)
EESVAC-151(A) | Knowlet

Course: Environmental Studies (For Arts) | Semester: 2nd Semester (FYUG)
Time: 3 Hours | Full Marks: 70 | Pass Marks: 28

UNIT—I

Question 1 (All Parts) [4 x 1 = 4 Marks]

Question 2 (a) [2 Marks]

What is biogeochemical cycle? Mention types.

A biogeochemical cycle is the movement of chemical elements and compounds between living organisms and the physical environment. The two main types are:

  1. Gaseous Cycles: Such as the Nitrogen and Carbon cycles.
  2. Sedimentary Cycles: Such as the Phosphorus and Sulphur cycles.

Question 2 (b) [OR] [2 Marks]

What is food web? Give example.

A food web is a complex network of interconnected food chains in an ecosystem. Example: In a forest, a single plant may be eaten by a grasshopper, a rabbit, or a deer, which are in turn eaten by various predators like owls, foxes, or hawks.

Question 3 (a) [8 Marks]

Define ecosystem. Explain how the flow of energy takes place.

An ecosystem is a functional unit of nature where living organisms interact with each other and their physical environment. Energy flow follows the 10% Law:

  • Energy enters via the Sun and is captured by producers (plants).
  • It moves to primary consumers (herbivores), then secondary and tertiary consumers.
  • Energy flow is unidirectional and decreases at each level as energy is lost as heat.

Question 3 (b) [OR] [8 Marks]

What is ecological succession? Discuss types with examples.

Ecological succession is the gradual and predictable change in the species composition of a given area. Types include:

  • Primary Succession: Starts in a barren area where no life existed (e.g., bare rock, newly formed volcanic island).
  • Secondary Succession: Occurs in areas where a community was destroyed but soil remains (e.g., abandoned farmland, burnt forest).

UNIT—II

Question 6 (a) [8 Marks]

What are energy resources? Discuss the importance of alternative sources.

Energy resources are materials or phenomena that can be used to produce power or heat. Alternative sources (Solar, Wind, Hydro) are crucial because:

  • They are inexhaustible and sustainable.
  • They produce minimal pollution compared to fossil fuels.
  • They reduce dependency on imported non-renewable fuels.

Question 6 (b) [OR] [8 Marks]

What is deforestation? Describe causes and effects in India.

Deforestation is the permanent removal of trees to make room for something besides forest.

  • Causes: Agricultural expansion, shifting cultivation (Jhum), logging for timber, and infrastructure projects like dams.
  • Effects: Soil erosion, loss of biodiversity, disruption of water cycles, and increased greenhouse gases.

UNIT—III

Question 9 (a) [8 Marks]

Define biodiversity. Mention levels. Discuss biodiversity of N-E India.

Biodiversity is the variety of life at all levels of biological organization. Levels include Genetic, Species, and Ecosystem diversity. North-East India: This region is a global biodiversity hotspot, home to unique species like the One-horned Rhino and Hoolock Gibbon, and characterized by diverse forest types and high endemism.

Question 9 (b) [OR] [8 Marks]

Define biodiversity hotspots. Discuss global biodiversity hotspots.

Hotspots are regions with high levels of species richness and endemism that are under significant threat from human activity. Globally, there are around 36 recognized hotspots, including the Western Ghats and the Himalayas in India, which contain a high percentage of the world's plant species as endemics.

UNIT—IV

Question 12 (b) [8 Marks]

What is climate change? Discuss causes and effects.

Climate change refers to significant, long-term shifts in global weather patterns and temperatures.

  • Causes: Greenhouse gas emissions from fossil fuels, deforestation, and industrial processes.
  • Effects: Rising sea levels, melting glaciers, extreme weather events (floods, droughts), and shifts in ecosystems.

UNIT—V

Question 15 (a) [8 Marks]

What is environmental movement? Write a note on Chipko Movement.

An environmental movement is a social/political movement for the conservation of the environment. Chipko Movement: Started in the 1970s in Uttarakhand, villagers (led by women like Gaura Devi) hugged trees to prevent them from being felled by contractors. It emphasized the link between forest conservation and the livelihoods of local communities.

Exam Focus Enhancements

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  • Exam Tips: For 8-mark questions, always start with a clear definition and use bullet points for causes and effects.[span_37](end_span)
  • Common Mistakes: Do not confuse "Primary Succession" (starts from zero life) with "Secondary Succession" (starts from existing soil).
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  • Important Terms: KSSP (Kerala Sastra Sahitya Parishad), PAN (Peroxyacetyl Nitrate).[span_40](end_span)
  • Presentation: Always mention examples like "Solar" for renewable and "Coal" for non-renewable to justify definitions.