BioNotes

The Biosphere

  • Ecology: Study of interactions between organisms and their environment.

  • Greenhouse Effect: Warming of Earth’s atmosphere due to greenhouse gases.

Energy Flow

  • Autotroph: Organism that produces its own food (e.g., plants).

  • Primary Producer: Organisms that generate biomass (e.g., photosynthetic plants).

  • Heterotroph: Organism that consumes other organisms for energy.

  • Consumer: Organisms that rely on eating others for energy.

  • Food Chain: Linear sequence of organisms through which nutrients and energy pass.

  • Food Web: Complex network of feeding relationships among organisms.

  • Trophic Level: Position in a food chain/web.

  • Ecological Pyramid: Diagram showing energy or biomass at each trophic level.

  • Biomass: Total mass of living matter in a unit area.

  • Ecosystem Stability: Ability of an ecosystem to maintain equilibrium despite disturbances.

  • Energy Loss: Energy decreases as it moves up each trophic level (10% rule).

Cycles of Matter

  • Energy versus Matter: Energy flows, matter cycles in ecosystems.

  • Biogeochemical Cycle: Movement of elements/compounds through biotic and abiotic components.

  • Nitrogen Fixation: Process of converting nitrogen gas into usable forms by organisms.

  • The Carbon Cycle: Movement and transformation of carbon through the Earth's atmosphere, biosphere, and geosphere.

  • The Nitrogen Cycle: Pathway of nitrogen from the envronment into organisms and back.

Ecosystem Stability and Change

Ecological Relationships

  • Tolerance: Range of environmental conditions an organism can withstand.

  • Niche: Role/position of a species within its environment.

  • Predation: One organism preying on another.

  • Herbivory: Consumption of plants by animals.

  • Keystone Species: Species that has a disproportionately large effect on its environment.

  • Symbiosis: Close relationship between two species.

    • Mutualism: Both species benefit.

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

    • Commensalism: One species benefits, other unaffected.

Ecological Succession

  • Succession: Process of change in species structure over time in an ecosystem.

Population Growth

  • Carrying Capacity: Maximum population size that an environment can sustain.

Human Impact on the Biosphere

Human Activity and Ecosystem Stability

  • Climate Change: Long-term change in temperature and typical weather patterns.

  • Monoculture: Cultivation of a single crop in a given area.

  • Deforestation: Large-scale removal of trees.

  • Invasive Species: Non-native species that spread widely and disrupt ecosystems.

  • Biological Magnification: Increasing concentration of substances in organisms at higher trophic levels.

Biodiversity and Environmental Change

  • Biodiversity: Variety of different species within a given ecosystem.

  • Resilience: Ability of an ecosystem to recover from disturbances.

  • Ecosystem Services: Benefits provided by ecosystems to humans.

  • Conservation Biology: Study focused on protecting biodiversity.

  • Habitat Fragmentation: Splitting of ecosystems into smaller, isolated areas.

Humans and the Environment

  • Sustainable Development: Development that meets the needs of the present without compromising future generations.