B4.2 Ecological Niches
Theme: Form and Function
Organism structure determines ecological function through specialized adaptations that define each species' role in ecosystem processes and interactions with other species.
- Metabolic adaptations create distinct ecological roles: obligate anaerobes, facultative anaerobes, and obligate aerobes have structural differences that determine where they can function in oxygen gradients.
- Nutritional modes reflect structural specializations: photosynthetic organisms have light-capturing structures, holozoic animals have digestive systems for internal processing, mixotrophic protists combine both structural systems, saprotrophic decomposers have enzyme systems for external digestion, and archaea show diverse metabolic structures for various energy sources.
- Dentition structure directly reflects diet in hominids, where tooth form enables specific feeding functions.
- Herbivore-plant interactions demonstrate evolutionary form-function relationships: herbivores develop piercing and chewing mouthparts while plants evolve thorns, toxic compounds, and defensive structures.
- Predator-prey adaptations show reciprocal form-function evolution where predators develop hunting structures and behaviors while prey evolve defensive mechanisms.
- Light-harvesting adaptations of plants create forest ecosystem structure through different architectural strategies: canopy trees maximize height, lianas use climbing structures, epiphytes develop aerial attachment systems, and understory plants adapt to low-light conditions.
- Fundamental versus realized niches reflect how structural adaptations create potential ecological roles, but competition limits actual function based on structural constraints and competitive abilities.
- Competitive exclusion occurs when species with similar structural adaptations cannot coexist, leading to niche partitioning where structural differences enable species to occupy different functional roles.
Guiding Questions:
Guiding questions help students view the content of the syllabus through the conceptual lenses of both the themes and the levels of biological organization.
Linking Questions:
Linking questions strengthen students’ understanding by making connections between topics. The ideal outcome of the linking questions is networked knowledge.
Guiding questions help students view the content of the syllabus through the conceptual lenses of both the themes and the levels of biological organization.
- 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?
Linking Questions:
Linking questions strengthen students’ understanding by making connections between topics. The ideal outcome of the linking questions is networked knowledge.
- What are the relative advantages of specificity and versatility?
- For each form of nutrition, what are the unique inputs, processes and outputs?
Key Terms to Know:
|
Abiotic
Absorb Algae Animal Archaea Assimilate Adenosine Triphosphate (ATP) Autotroph Behavioral Adaptation Biotic Carnivore Chemical Adaptation Competitive Exclusion Competition Decomposer Deduction Dentition Detoxify Digest Domain |
Ecosystem
Epiphyte Euglena Facultative Anaerobe Fundamental Niche Fungi Herbivore Herbivory Heterotroph Holozoic Hominidae Homo floresiensis Homo sapiens Ingest Inorganic Liana Mixotroph Niche Obligate Anaerobe Obligate Aerobe |
Omnivore
Organic Oxidation Paranthropus robustus Photosynthesis Physical Adaptation Plankton Plant Predation Predator Prey Prokaryote Protist Realized Niche Saprotroph Secondary Compounds Species Thorns Toxin |
