Environmental Studies Flashcards
Organism
Individual form of life composed of a single cell or complex of cells that are capable of growing and reproducing
Individual
A single organism capable of independent existence
Species
A group of closely related organisms that are very similar to each other and are usually capable of interbreeding and producing fertile offspring
Population
A group of organisms of the same species that occupy the same area and can breed freely with each other
Community
A group of different species that inhibit and interact in a particular area
Ecosystem
Groups of different species of organisms that interact with each other and with the environment
Biosphere
The part of the earth where living organisms are found
Mortality
Number of deaths in a population per 1000 people in a year
Natality
Number of births in a population per 1000 people in a year
Ecology
The study of the interactions of organisms with their physical and biological environments and how these determine the distribution and make up a populations with in an ecosystem
Population ecology
The fluctuations in the size of a population and the factors, both physical and social that regulates these fluctuations
Population size
The total number of individuals in a population
Immigration
Individuals move into a population stay
Emigration
Individuals leave a population and do not return
Closed population
No immigration immigration occurs - only affected by birth and death rates
Environmental resistance
The total number of factors that stop a population from reproducing to its maximum rate
Carrying capacity
The population density that the environment can support
Limiting factors
Factors that help to regulate the growth of a population
Stable population
Numbers decrease when its size exceeds the carrying capacity but increase again when numbers fall below the carrying capacity
Unstable population
Develops if the population far exceeds the carrying capacity
Density independent factors
Limit the growth of a population as a result of natural factors and not because of the density or number of organisms
Density dependent factors
Have a greater effect when the population density is high
Predation
A biological interaction where one species, the predator, kills and eats another species, the prey
Parthenogenesis
Cloning reproduction (no gametes involved)
Co-evolution
One organism changes because of the other in a given environment
Food web
Interconnected set of all the food chains in an ecosystem
Competition
When two or more individuals compete for the same resources that are in short supply
Intraspecific competition
Occurs between individuals of the same species
Inter specific competition
Occurs between individuals of different species where the inches in a habitat are very similar
Ecological niche
All the conditions necessary for an organism to survive and reproduce
Specialization
The structural a behavioral adaptations that enable individuals of different species to co-exist
Competitive co-existence
Arises when two competing species co-exist in the same habitat
Competitive exclusion
Occurs when one of the two competing species is more successful than the other
Resource partitioning
The evolutionary process wherebye species with similar requirements, living in the same habitat, evolve specialized traits that enable them to utilize the resources differently, creating separate niches to reduce interspecific competition and make co-existence possible
Stratification
Varying size and species which creates a vertical structure that divides the vegetation into layers
Ecological succession
Predictable pattern of gradual change over time in the types of species in a community following a disturbance
Annuals
Herbs and weeds
Climax community
The last semi-stable stage or the endpoint of succession
Social organization
Structure of relationships within a group
Mob
To surround and overpower
Dilution effect
The greater the number of individuals in a group, the greater the survival chances are of the individual
Confusion and distraction effect
As predator tried to single out its prey, the herd scatters in all directions, confusing the predator
Eusocial
Species that exhibit the highest level of social organization
Termetaria
Farces and saliva of termites used to cement termite mounds
Population pyramid
A bar graph that shows the composition, by age and sex, of a nation’s population at the time of a census
Structure
The relative number of individuals of each age in a population
Biocapacity
The amount of productive land and water available to produce the resources we use and to absorb the waste we produced
Ecological debtor country
A country with an ecological deficit
Ecological creditor country
A country which does not have an ecological deficit
Conservation
Protecting something and keeping it in a healthy state
Sustainable development
The development that meets the needs of the present while not compromising the needs a future generations
