Ecology, Microbes & Evolution

Master this topic with zero to advance depth.

Biology Decoder: The Living World

Phase 1: The Foundation (What is an Ecosystem?)

An ecosystem is a biological community of interacting organisms and their physical environment.

1. The Energy Flow (Food Chain)

  • Producers: Plants (Make their own food).
  • Consumers: Animals (Eat others).
  • Decomposers: Fungi/Bacteria (Clean up the dead).
  • 10% Rule (Lindeman's Law): Only 10% of energy passes to the next level in a food chain.

Phase 2: The Core Logic (Microbes in Welfare)

1. The Good Microbes

MicrobeTypeUsage
LactobacillusBacteriaTurning Milk into Curd.
YeastFungiMaking Bread, Alcohol (Fermentation).
PenicilliumFungiMaking the first Antibiotic (Penicillin).
RhizobiumBacteriaFixing Nitrogen in plants (Pulses).

Phase 3: The Exam Edge (Evolution & Environment)

1. Evolution (The Story of Change)

  • Charles Darwin: Proposed "Natural Selection". Origin of Species.
  • Jean-Baptiste Lamarck: Proposed theory of "Use and Disuse" (Wrong theory, but important for exams).
  • Vestigial Organs: Organs that were useful for ancestors but not for us (Appedix, Wisdom teeth).

2. Biodiversity & Pollution

  • Endangered Species: Red Data Book (IUCN).
  • Acid Rain: Caused by Oxides of Sulfur & Nitrogen.
  • Global Warming: Caused by Methane (CH4) & CO2 trapping heat.