Science 1206 Ecology Review #1

Ecology

The branch of biology that deals with the relations of organisms to one another and to their physical surroundings.

Ecosystem

A system made up of all the interacting living and non-living parts of a certain place, as defined by an ecologist.

Habitat

The area and resources used by a particular species or an assemblage of animals and plants together with their abiotic environment.

Niche

The way an organism occupies a position in an ecosystem, including all the necessary biotic and abiotic factors.

Biodiversity

the variety of all living things and their interactions.

Biotic potential

The maximum number of individuals a species can produce.

Population

A group of organisms of one species that lives in a particular geographic area, at a specific time, and can successfully reproduce.

Community

A group of species that are commonly found together.

Biotic Limiting Factors

Anything that constrains a population's size and slows or stops it from growing. Some examples are: : food, mates, and competition with other organisms for resources.

Abiotic Limiting Factors

Any non-living thing that constrains a population's size and slows or stops it from growing. Some examples are: temperature, wind, climate, sunlight, rainfall, soil composition, natural disasters, and pollution.

Producer

Organisms that can make their own food in an ecosystem.

Consumer

A living organism which gets its nourishment by eating other living organisms.

Decomposer

Organisms that break down dead or decaying organisms.

Saprobe

Organisms which get their nutrients from breaking down dead and decaying materials.

Autotroph

An organism that can produce its own food using light, water, carbon dioxide, or other chemicals.

Heterotroph

An organism that eats other plants or animals for energy and nutrients.

Food chain

A group of organisms linked in order of the food they eat, from producers to consumers, and from prey, predators, scavengers, and decomposers.

Food web

It consists of all the food chains in a single ecosystem.

Trophic levels

The position of an organism in the food chain.

Primary Consumer

Make up the second trophic level. They are also called herbivores. They eat primary producers.

Secondary Consumer

Largely carnivores that feed on the primary consumers or herbivores.

Tertiary Consumer

Animals that eat secondary consumers ie carnivores that feed on other carnivores.

Herbivore

An organism that mostly feeds on plants.

Carnivore

An organism that eats mostly meat, or the flesh of animals.

Omnivore

An organism that regularly consumes a variety of material, including plants, animals, algae, and fungi.

Detrivore

An organism that feeds on dead and decomposing organic matter.

Predation/predator-prey relationship

Occurs when a predator hunts, kills and consumes another organism (its prey) for food.

Interspecific Competition

Individuals of different species compete for territory or resources.

Intraspecific Competition

Competition between organisms of the same species.

Symbiosis

Means “living together”. A long term relationship between organisms of two different species that live together in close association.

Parasitism

One organism (the parasite) benefits and the other (the host) is harmed but not always killed.

Mutualism

Both species benefit from the relationship.

Commensalism

One species benefits, the other is neither hurt nor helped.

Energy Transfer

The changes in energy that occur in and between organisms within an ecosystem.

Carbon Cycle

Nature's way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again.

Organic Matter

Any of a large class of chemical compounds in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen, or nitrogen.

Inorganic Matter

A substance that does not contain both carbon and hydrogen.

Photosynthesis

Plants, green algae and other plant-like organisms convert light energy into chemical energy, producing oxygen in the process. Formula: 6 CO2 + 6 H2O→C6H12O6 + 6 O2 (Carbon dioxide + Water + Light energy→Sugar + Oxygen).

Cellular Respiration

A reaction in the cells of most organisms that releases stored energy, by combining sugars and oxygen to produce carbon dioxide and water. Formula: 6 CO2 + Energy (Sugar + Oxygen→Carbon dioxide + Water + Light energy).

Greenhouse Effect

The process by which gasses build up energy in the form of warmth in the atmosphere by absorbing infrared radiation from the Earth’s surface.