Unit 10 - Ecology and Environment

1. Organisms and Environment

Key Topics

·         Population Interactions:

o    Mutualism: Both species benefit (e.g., pollination by insects).

o    Competition: Two species compete for the same resource.

o    Predation: One organism (predator) feeds on another (prey).

o    Parasitism: One species benefits at the expense of another.

·         Population Attributes:

o    Growth: Exponential vs. logistic growth models.

o    Birth Rate and Death Rate: Indicators of population dynamics.

o    Age Distribution: Proportion of individuals in different age groups.

Critical Insights

·         Understand examples of each type of interaction.

·         Learn the mathematical models for population growth (e.g., dN/dt=rNdN/dt = rNdN/dt=rN).

·         Be familiar with survivorship curves and their ecological implications.

2. Ecosystem

Key Topics

·         Patterns and Components:

o    Biotic (living organisms) and abiotic (non-living components) factors.

·         Productivity:

o    Gross Primary Productivity (GPP): Total energy captured by producers.

o    Net Primary Productivity (NPP): Energy available to consumers (NPP=GPP−RespirationNPP = GPP - RespirationNPP=GPP−Respiration).

·         Decomposition:

o    Breakdown of organic matter by decomposers.

·         Energy Flow:

o    Unidirectional flow through trophic levels.

o    Loss of energy at each level (~10% rule).

·         Ecological Pyramids:

o    Pyramid of numbers, biomass, and energy.

Critical Insights

·         Focus on energy flow diagrams and food chains/webs.

·         Memorize key differences between pyramids of numbers, biomass, and energy.

·         Understand the role of decomposers in nutrient cycling.

3. Biodiversity and Its Conservation

Key Topics

·         Concept & Patterns of Biodiversity:

o    Species richness increases near the equator (latitudinal gradient).

·         Importance of Biodiversity:

o    Ecological balance, economic value, ethical reasons.

·         Loss of Biodiversity:

o    Causes: Habitat destruction, pollution, invasive species, overexploitation.

·         Conservation Strategies:

o    In-situ: National parks, biosphere reserves, sacred groves.

o    Ex-situ: Zoos, botanical gardens, seed banks.

·         Hotspots & Endangered Species:

o    Biodiversity hotspots: Regions with high endemic species under threat.

o    Red Data Book: List of endangered species.

Critical Insights

·         Learn examples of biodiversity hotspots in India (e.g., Western Ghats).

·         Understand the criteria for classifying endangered species.

·         Study case studies on conservation efforts like Project Tiger.