Ecology and Population Dynamics Quiz

Characteristics of Ecology

• Ecology is the study of interactions between organisms and their environment.
• Key levels of organization: Organism, Population, Community, Ecosystem, Biome, Biosphere.

Factors in Population Dynamics

• Biotic Factors: Living components affecting populations, like competition and predation.
• Abiotic Factors: Non-living components, such as climate, soil, and water.

Population Growth Models

• Exponential Growth (J Curve):

  • Occurs when resources are unlimited.
  • Characterized by rapid population increase, typical in species like bacteria and humans.

• Logistic Growth (S Curve):

  • Population grows until it reaches carrying capacity, then stabilizes due to limited resources.
  • Carrying capacity refers to the maximum population sustainable in an environment.

Population Influencing Factors

• Increase: Births, immigration, expanding territories, technological advancements, decreasing predators.
• Decrease: Deaths, emigration, resource depletion, sterility, introduction of predators.

Predator-Prey Dynamics

• Changes in predator and prey populations are interdependent; increase in prey leads to increased predator populations, and vice versa.

Organismal Interactions

• Predation: One organism hunts another for nourishment.
• Herbivory: Consumption of plants by organisms.
• Symbiosis: Close interactions between different species, beneficial to one or both.

Types of Symbiotic Relationships

• Mutualism (+,+): Both species benefit, such as pollinators and flowering plants.
• Commensalism (+,0): One species benefits while the other is unaffected.
• Parasitism (+,-): One organism benefits at the expense of the other.

Community Ecology Concepts

• Competition: Organisms compete for limited resources such as food, water, and space.
• Keystone Species: A species that has a disproportionately large effect on its environment relative to its abundance.

Succession in Ecosystems

• Primary Succession: Development of an ecosystem in an area with no previous soil, starting with pioneer species.
• Secondary Succession: Recovery of an ecosystem after a disturbance, usually faster due to existing soil.

Trophic Levels and Energy Flow

• Autotrophs: Producers that create energy (e.g., plants).
• Heterotrophs: Consumers that obtain energy by eating others.
• Detritivores: Organisms that consume decomposing organic matter.
• Biomass Pyramid: Illustrates the energy or biomass at each trophic level.

Environmental Issues

• Bioaccumulation: Build-up of substances, like pesticides, in an organism over time.
• Biomagnification: Increase of toxic substances in organisms at higher trophic levels.
• Climate Change: Alteration of global weather patterns due to human activities.
• Biodiversity: Variety of life in an ecosystem, crucial for resilience and ecological balance.
• Pollution: Introduction of harmful substances into the environment, affecting health and ecosystems.

Conservation Efforts

• Overexploitation: Excessive use of species leading to population decline.
• Habitat Destruction: Loss of habitats due to human activities, impacting biodiversity.
• Edge Effects: Changes in population or community structures that occur at the boundary of two habitats.
• Eutrophication: Nutrient overload in water bodies leading to excessive plant growth and oxygen depletion.

Climate Terms

• Carbon Source: Processes that release more carbon than they absorb.
• Carbon Sink: Natural environments that absorb and store carbon dioxide from the atmosphere.

Exam Preparation Suggestions

• Review definitions and implications of ecological terms.
• Understand population dynamics and graphs related to predator-prey relationships.
• Familiarize with types of symbiotic interactions and their ecological impacts.
• Study key ecological concepts such as succession, trophic levels, and environmental issues.