Biology Study Sheet

Only available on StudyMode
  • Download(s) : 60
  • Published : February 3, 2013
Open Document
Text Preview
Chapter One

Ecology – the study of the many interactions in the world around us - body of knowledge concerning the economy of nature, investigation of the total relations of the animal both to its biotic and abiotic environment

- concept developed by Ernst Haeckel in 1900s
- The study of the interactions of organisms with one another and with their environment
- not “the ecology” (wouldn’t say protect “the physics”)
- not Environmental Science – study of how natural world works

Ecological Systems
Nested hierarchy
- lowest level: look at individual organisms
- biosphere highest level
- organism most fundamental unit of ecology
- organisms interact with the environment that is outside the individual, therefore is lowest level, do not go beneath to organ systems, it is the level at which independent sexual reproduction occurs, natural selection occurs between individuals, etc.

ecosystem – assemblages of organisms together with their physical and chemical environment; a large and complex ecological system; eg) forest, prairie, estuarine ecoystem; all ecosystems are linked in a single biosphere

Levels of Study
Biosphere
- global processes
- includes all environments and organisms on Earth
- exchanges of energy/nutrients by wind/water between ecosystems Ecosystems
- energy flux and cycling of nutrients
- have no clearly defined boundaries
Communities
- many populations of different kinds living in the same place
- have no clearly defined boundaries
Population
- social system of reproduction, survival, interactions
- population dynamics: density, dispersion, size, composition
- the unit of evolution
Organism
- conditions in which an organism can survive in
- individual’s interactions with biotic and abiotic environment
- individual sexual reproduction
- natural selection

Ecological Roles
Taxonomic Approach (Bio1020 approach)
– roles of individuals in these groups can be quite different even though similarity from ancestors; roles are related to levels
Organism Approach
– emphasizes the way in which an individual’s form, physiology, and behaviour help it to survive in its environment – seeks to understand why each type of organism is limited to some environments and not others; related organisms different in dif places

Population approach
– is concerned with variation in the numbers of individuals, the sex ratio, the relative sizes of age classes, and the genetic makeup of a population through time Community Approach
– concerned with understanding the diversity and relative abundances of different kinds of organisms living together in the same place – focusses on interactions between populationg; limitting and promoting coexistence of species Ecosystem Approach

– describes organisms and their activities in terms of “currencies,” primarily amounts of energy and various chemical elements essential to life Function
– organism’s role in the functioning of the ecosystem; occurs because of natural selection; not “purpose” – ecosystem function reflects the activities of organisms as well as physical and chemical transformations of energy and materials in the soil, atmosphere, and water

Roles change with evolution
– depends on other community members/roles; evolutionary responses include changing roles in order for populations to adapt
Habitat
– conditions of environment (physical and biological conditions) – Circular: plants define habitat; respond to habitat; alter habitat
Niche (interrelated to habitat)
– organisms’ range of tolerated conditionsand ways of life; role
Conditions of Life: Energy and Nutrients
– photosynthesis: begins energy flow cycles
– nutrients: cycling of energy
Biosphere Approach
– concerned with the largest scale in the hierarchy of ecological systems; movements of air and water, energy and chemical elements – currents and winds carry the heat and moisture that define the climates at each location on...
tracking img