Ecology Flashcards
(13 cards)
What is an organsim?
a living thing, may be either unicellular (a single cell) or, as in the case of humans, comprise many trillions of cells grouped into specialized tissues and organs. The term multicellular (many cells) describes any organism made up of more than one cell.
What is a population?
A group of organism of the same species which live in the same habitat at the same time where they can freely interbreed
What is a community?
All the populations of the different species living and inter-acting in the same ecosystem
What is a habitat?
The characteristics of the type of environment where an organism normally lives. (e.g. a stony stream, a deciduous temperate woodland, a pond)
What is a ecosystem?
community
An ecosystem is a community of living organisms (plants, animals and microbes) in conjunction with the nonliving components of their environment (things like air, water and mineral soil), interacting as a system.[2] These biotic and abiotic components are regarded as linked together through nutrient cycles and energy flows.
What is a biome?
a grouping of terrestrial ecosystems on a given continent that are similar in vegetation structure, physiognomy, features of the environment and characteristics of their animal communities.
What is the biosphere?
the global sum of all ecosystems. It can also be called the zone of life on Earth, a a grouping of terrestrial ecosystems on a given continent that are similar in vegetation structure, physiognomy, features of the environment and characteristics of their animal communities. (apart from solar and cosmic radiation), and self-regulating system.
What is biodiversity?
The total number of different species in an ecosystem and their relative abundance
What are biotic and abiotic factors?
Abiotic factors: non living chemical and physical factors in the environment which affect ecosystems.
e.g. temperature, characteristics of the soil, water, light
Biotic factors: is any living component that affects another organism, including animals that consume the organism in question, and the living food that the organism consumes.
e.g. producers, consumers, decomposers
What is the ecological niche?
= the specific set of biotic and abiotic resources used by an organism (or a population) uses in its environment.
An organism’s habitat + role + tolerance limits to all limiting factors
What does the niche of a species consist of?
- its role in the ecosystem (herbivore, carnivore, producer etc)
- its tolerance limits (e.g. soil pH, humidity)
- its requirements for shelter, nesting sites etc
–> all varying through time
What is competition?
Occurs when individuals have to share resources in short supply
Interspecific competition (members of two species) for resources such as food, living space, etc…
Intraspecific competition (members of same species) for food, mates, breeding sites for example. Density dependent.
What is the competitive exclusion principle?
- 2 species cannot coexist permanently in a community if their niches are identical
- ecologically similar species can coexist in a community if natural selection causes resource partitioning (1 or more diffference in their niches arise though time)
