B4.2 Ecological Niches

Page 1: Introduction to Ecological Niches

  • Theme: Form and Function

  • Level of Organisation: Ecosystems

  • Context: This is part of the study for First Exams in 2025 focusing on the role of ecological niches in ecosystems.

  • Conceptual Framework: The power of science allows understanding ecological interactions.

Page 2: Combined Content Overview

  • SL and HL content combined for comprehensive understanding.

  • Focus: Utilizing the power of science in ecological studies.

Page 3: Guiding Questions

  • Key Questions:

    • What are the advantages of specialized modes of nutrition to living organisms?

    • How are the adaptations of a species related to its niche in an ecosystem?

  • Content Level: Both SL and HL.

Page 4: Core Topics in Ecological Niche

  • B4.2 Content:

    • B4.2.1: Definition of an ecological niche.

    • B4.2.2: Types of organisms: obligate anaerobes, facultative anaerobes, and obligate aerobes.

    • B4.2.3: Photosynthesis as a nutrition mode for plants, algae, and some prokaryotes.

    • B4.2.4: Holozoic nutrition in animals.

    • B4.2.5: Mixotrophic nutrition in protists.

Page 5: Continued Content on Nutrition

  • B4.2.6: Saprotrophic nutrition in fungi and bacteria.

  • B4.2.7: Diversity of nutrition in archaea.

  • B4.2.8: Relationship between dentition and diet in family Hominidae.

  • B4.2.9: Herbivore adaptations against herbivory.

Page 6: Adaptations in Prey and Plants

  • B4.2.10: Adaptations of predators and prey.

  • B4.2.11: Plant adaptations for light harvesting.

  • B4.2.12: Concepts of fundamental and realized niches.

  • B4.2.13: Competitive exclusion principle and ecological niche uniqueness.

Page 7: Key Terms

  • Ecological Niche

  • Biotic Factors

  • Abiotic Factors

  • Nutritional Types: Obligate Anaerobes, Facultative Anaerobes, Obligate Aerobes, etc.

Page 8: Additional Key Terms

  • Types of Organisms: Archaea, phototrophs, chemolithotrophs, organotrophs.

  • Feeding Strategies: Omnivore, herbivore, predator, prey adaptations (camouflage, venom, mimicry).

Pages 9-11: Ecological Niche Definition

  • Definition: The ecological niche encompasses the role of a species within its ecosystem, influenced by biotic and abiotic interactions.

  • Key Factors: Food acquisition, growth, survival, reproduction.

Pages 12-14: Oxygen as a Limiting Factor

  • Oxygen Levels: Define how obligate anaerobes, facultative anaerobes, and obligate aerobes differ in oxygen tolerance.

  • Oxygen's Role: Understanding oxygen’s impact on habitat viability for various organisms.

Pages 15-20: Nutrition Types

  • Aerobes and Anaerobes:

    • Obligate Anaerobes: Cannot survive with oxygen (e.g., waterlogged soils).

    • Facultative Anaerobes: Can switch between aerobic and anaerobic conditions.

    • Obligate Aerobes: Require oxygen for survival.

Pages 21-26: Holozoic and Mixotrophic Nutrition

  • Holozoic Nutrition: Ingest, digest, absorb nutrients.

  • Mixotrophic Nutrition:

    • Euglena: Example of a freshwater mixotrophic protist.

    • Modes: Obligate vs. facultative mixotrophs.

Pages 27-30: Diversity in Archaea

  • Archaea: Metabolically diverse, live in extreme environments.

  • Nutrition Methods: Phototrophs, chemolithotrophs, organotrophs.

Pages 31-36: Dentition and Diet

  • Studying Dentition: Correlation between dentition and dietary habits in Hominidae.

  • Adaptations: Physical adaptations of herbivores for plant consumption; plant defenses against herbivory.

Pages 37-44: Adaptations of Predators and Prey

  • Predator Adaptations: Physical, chemical (venom), and behavioral strategies to hunt.

  • Prey Adaptations: Defensive mechanisms; camouflage, mimicry, and group behavior to avoid predation.

Pages 45-52: Strategy of Plant Adaptations

  • Plant Strategies:

    • Adaptive features for light harvesting: height, canopy structures, leaf designs.

    • Development of traits to prevent herbivory through physical and chemical means.

Pages 53-66: Fundamental vs. Realized Niches

  • Concepts: Understanding potential (fundamental) vs. actual (realized) niches impacted by competition.

  • Competitive Exclusion: Fundamental principles governing species interaction within niches.

Pages 67-80: Review and Resources

  • Key Term Review: Recapitulation of important ecological terms and concepts.

  • Further Resources: Options for further exploration of ecological niches and related themes.