Topic 5 Key Words

Organism - An individual living thing that can react to stimuli, reproduces, grow, and maintain homeostasis. It can be a virus, bacterium, protist, fungus, plant or an animal.

Ecology - the distribution, abundance and interactions of living organisms at the level of communities, populations, and ecosystems, as well as at the global scale.

Biotic - Of, pertaining to, or produced by life or living organisms (of an ecosystem).

Biosphere - The part of the earth where living things exist.

Food Web - interconnecting food chains in an ecological community

Food Chain - A feeding hierarchy in which organisms in an ecosystem are grouped into trophic (nutritional) levels and are shown in a succession to represent the flow of food energy and the feeding relationships between them.

Community - An ecological unit composed of a group of organisms or a population of different species occupying a particular area, usually interacting with each other and their environment.

Species - An individual belonging to a group of organisms (or the entire group itself) having common characteristics and (usually) are capable of mating with one another to produce fertile offspring.

Photosynthesis - The synthesis of complex organic material using carbon dioxide, water, inorganic salts, and light energy (from sunlight) captured by light-absorbing pigments, such as chlorophyll and other accessory pigments.

Biome - A major ecological community of organisms adapted to a particular climatic or environmental condition on a large geographic area in which they occur.

Niche - The interrelationship of a species with all the biotic and abiotic factors affecting it.

Producer - An autotrophic organism capable of creating complex organic compounds from simple inorganic molecules through the process of photosynthesis (using light energy) or through chemosynthesis (using chemical energy).

Omnivore - An animal that feeds on both plants and animals to survive.

Consumer - An organism that generally obtains food by feeding on other organisms or organic matter due to lack of the ability to manufacture own food from inorganic sources; a heterotroph.

Carnivore - An animal or plant (particularly insect- and invertebrate-eating plants) that requires a staple diet consisting mainly or exclusively of animal tissue through predation or scavenging.

Phototroph - An organism, typically a plant, obtaining energy from sunlight as its source of energy to convert inorganic materials into organic materials for use in cellular functions such as biosynthesis and respiration.

Ecosystem - A system that includes all living organisms (biotic factors) in an area as well as its physical environment (abiotic factors) functioning together as a unit.

Micro-Habitat - A habitat within a habitat, which possesses unique properties where new variations of life can exist and thrive due to the unique conditions that the microhabitat offers.

Trophic Pyramid – (ecological pyramid) a graphical representation designed to show the biomass or biomass productivity at each trophic level in a given ecosystem.

Speciation - The process in which new genetically distinct species evolve usually as a result of genetic isolation from the main population.

Habitat - Place where an organism or a biological population normally lives or occurs.

Autotroph - A organism capable of making nutritive organic molecules from inorganic sources via photosynthesis (involving light energy) or chemosynthesis (involving chemical energy).

Succession - The progressive replacement of one dominant type of species or community by another in an ecosystem until a stable climax community is established.

Population - A group of organisms of one species that interbreed and live in the same place at the same time (e.g. deer population).

Hetrotroph - An organism that is unable to synthesize its own organic carbon-based compounds from inorganic sources, hence, feeds on organic matter produced by, or available in, other organisms.

Herbivore - An animal that consumes herbaceous vegetation.

Competition - A symbiotic relationship between or among living things for resources, such as food, space, shelter, mate, ecological status, etc.

Evolution - The change in genetic composition of a population over successive generations, which may be caused by natural selection, inbreeding, hybridization, or mutation.

Abiotic - a nonliving physical and chemical attribute of a system, for example light, temperature, wind patterns, rocks, soil, pH, pressure, etc. in an environment.

Chemotroph - An organism (typically a bacterium or protozoan) that obtains energy through chemical process, which is by the oxidation of electron donating molecules from the environment, rather than by photosynthesis.

Nutrient - Food or any nourishing substance assimilated by an organism, and required for growth, repair, and normal metabolism.

Predation - A form of symbiotic relationship between two organisms of unlike species in which one of them acts as predator that captures and feeds on the other organism that serves as the prey.