IB Bio B4.2 Ecological Niches

Ecological niche

The unique functional role a species plays within its ecosystem, defined by interactions with biotic and abiotic factors

Zone of tolerance

Range of environmental conditions that an organism can withstand and still survive and reproduce

Obligate aerobe

An organism that requires oxygen for survival and growth

Obligate anaerobe

An organism that cannot survive in the presence of oxygen; it’s toxic for them

Facultative anaerobe

An organism that can survive with or without oxygen

Holozoic nutrition

Organisms ingest whole pieces of food before it is digested

Stages of holozoic nutrition

Ingestion, digestion, absorption, assimilation, egestion

Mixotroph

Organism that isn’t exclusively autotrophic or heterotrophic

Facultative mixotroph

Can be entirely autotrophic, heterotrophic, or a combination of both

Obligate mixotroph

Cannot grow unless using both autotrophic and heterotrophic methods

Phototrophic

Absorption of light energy through pigments

Chemotrophic

Oxidation of inorganic chemicals

Heterotrophic

Oxidation of carbon compounds ingested from another organism

Herbivore teeth

Flat and wide for chewing plants

Omnivore teeth

Teeth to crush and grind and teeth to tear

Homologous insect mouthparts

Came from the same ancestral mouthparts

Types of insect mouthparts

Jaw-like, tubular, scissor

Adaptations of plants

Spines, chemical signaling, and toxins

Adaptations of predators

Teeth, venom, hunting techniques

Adaptations of prey

Camouflage, vibrant coloring/accumulation of toxins, schooling of fish

Adaptations of plants to harvest light

Fast-growing shoot, using trees as support to climb to the canopy, growing on trees (epiphytes), becoming shade tolerant

Fundamental niche

theoretical range of tolerance of a species

Realized niche

actual range a species occupies with competition in an ecosystem

Competitive exclusion

When two species exclude each other from their niche due to overlap

Archaea

Domain of life using light, chemicals, or carbon molecules as an energy source