BIO Chapter 1:
ecology, greek meaning “house, study oh how organism interact in an
Environmental supports systems: things on which humanity relies for fod,
water and protection against natural catastrophes.
Some examples of these are: watersheds, agriculture lands, and wetlands.
An ecological system may be an organism, a population, or assemblage of
populations together, an ecosystem or the biosphere.
Each smaller system is a subset (part) of the next larger one.
Most fundamental part of ecology: organism
Ultimately, all environments are linked together in a single biosphere [known
as the ultimate ecological system]
Population: many organisms of the same kind living together
Populations differ from organism because populations are potentially
immortal; births replace deaths
They also have roper ties such as geographic ranges, densities, and variations
in size or composition(evolutionary responses).
Community: populations of different kind make up an ecological community.
Communities have no “visible” boundries
Organism approach: the way in which an individuals form, physiology, and
behaviour help it to survive in its environment.
This explains why organisms are limited to certain environments
For instance, moist areas are home to trees, where as hot and dry areas are
home to shrubs with small leaves.
This helps one understand adaptations: modifications of structures or
function to better suit an organism increase survival + fitness
Population Approach: variations in the number of individuals, sex ratio, age,
www.notesolution.com Community Approach: interactions between populations, which both promote
and limit the coexistence of species. Eg feeding relationship [movement of
Ecosystem Approach: organism and their activities in terms of energy and
essential elements such as oxygen, carbon, nitrogen and so on.
Deals with movements of energy, and how this effects climate and other
Biosphere Approach: movements of air and water, and the energy and
For instance, ocean currents and wind carry heat and moisture that define
climates, which in turn govern the distribution of organisms, composition of
communities, and the productivity of ecosystems.
Symbiosis- physical relationship between two different types of organisms
When one provides another with something they lack, it is called mutualism.
The opposite is parasitism,