IB SL/HL Study Guide: Ecosystems Interactions and Interdependence

A set of flashcards covering key concepts related to ecosystems, interactions, adaptations, nutrition modes, and community dynamics.

Habitat

Place where an organism lives, including physical location and resources.

Ecosystem

Community of organisms interacting with each other and their abiotic environment.

Abiotic factors

Non-living components of an environment that affect living organisms, e.g., temperature, moisture, pH.

Ecological niche

Role of a species in its ecosystem, including its resource use and relationships with other organisms.

Fundamental niche

The potential mode of existence of a species, considering the full range of conditions under which it can survive.

Realized niche

The actual conditions under which a species exists, influenced by biotic interactions.

Competitive exclusion

Theory that two species competing for the same resources cannot coexist if other ecological factors are constant.

Photosynthesis

Process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll.

Holozoic nutrition

A type of nutrition in which organisms ingest solid food materials; includes ingestion, digestion, absorption, and assimilation.

Mixotrophy

Mode of nutrition combining both autotrophic and heterotrophic mechanisms, as seen in organisms like Euglena.

Saprotrophic nutrition

Nutrition obtained by the external digestion of organic matter by decomposers like fungi and bacteria.

Obligate anaerobe

Organism that cannot survive in the presence of oxygen and obtains energy through fermentation or anaerobic respiration.

Facultative anaerobe

Organism that can survive with or without oxygen, using aerobic respiration when it's available.

Interspecific competition

Competition between individuals of different species for the same resources, which can affect population dynamics.

Intraspecific competition

Competition between individuals of the same species for limited resources, impacting population growth.

Carrying capacity

The maximum population size that an environment can sustainably support, determined by resources.

Decomposer

Organisms that break down dead or decaying organic material, recycling nutrients back into the ecosystem.

Energy pyramid

A graphical representation showing the amount of energy available at each trophic level in an ecosystem.

Trophic level

Position or level in a food chain or food web, describing the flow of energy and nutrients.