Ecology Flashcards
Ecology
The study of the interactions between organisms and their environment
Two components of an organisms’s enviroment:
Physical (abiotic)
Living (biotic)
Physical environment includes:
climate, temperature, availability of light and water, and the local topology.
Biotic environment
All living things that directly or indirectly influence the life of the organism.
Organism
Individual unit of an ecological system.
Population
Group of organisms of the same species living together in a given location.
Species
Any group of similar organisms that are capable of reproducing with each other.
Community
Populations of different plants and animal species interacting with each other in a given encironment
Biotic environment
Only includes the population and not the physical environments
Ecosystem
Includes the community and the environment.
Biosphere
Includes all portions of the planet that support life- the atmosphere, the lithosphere (rock and soul surface) and the hydrosphere (oceans). RELATIVELY THIN LAYER
Photic zone
In water- the top layer through which light can penetrate. Where all of the photosynthesis takes place.
Aphotic zone
only animal life and other heterotrophic life exist
What is soil affected by?
Acidity
Texture of soil
Minerals (nitrates and phosphates) affect the type of vegetation that can be supported
Humus quantity is determined by the amount of decaying plant and animal life in soil.
Niche
Defines the functional role of an organism in its ecosystem.
Habitat
The latter is the physical place where an organism lives.
What does the niche describe?
What the organism eats, where and how it obtains its food, what climatic factors it can tolerate and which are optimal the nature of its parasites and predatos, where and how it reproduces and so on.
True or false: two organisms can occupy the same niche
FALSE
ORGANISMS occupying the same niche compete:
for food, water, light, oxygen space, minerals, and reproductive sites.
Why do herbivores have long digestive tracts?
This provides greater surface area and time for digestion.
Symbiotic bacteria of herbivores
Capable of digesting cellulose- inhabit the digestive tracts if herbivores.
Symbiosis
Close interrelationship of two different species.
what kind of organism if most adept at defense?
Herbivores because they are more often prey.
Obligatory symbiotic relationship:
One or both organisms cannot survive without the other.