Genetic Population And Ecosystems Flashcards
What is ecology
Scientific study of the interactions between organisms and their environment that determine their distribution and abundance
What is a biosphere
Encompasses all living organisms found on earth together with th neon-living part of their environment
(Includes lands, ocean..)
What are biomes
Regions of the world with similar climate, animals and plants
What is interdependence
They way in which each species in a community depends on other species for things such as food, shelter, pollination, seed dispersal
What is an Ecosytems
A community of organisms and the non-living components of their environment (biotic and abiotic)
What is a population
Group of individuals of one species that occupy the same habitat at the same time and are potentially able to interbreed
What is a community
All the populations of different species which interact together in the same habitat at the same time
What is a habitat
Area in which an organism lives and that is characterised by physical condition a and other types of organisms present
What is the carrying capacity and what does it depend on
An ecosystem supports a certain size of a population
- effect of abiotic factors
-interactions between organsims- intra and interspecific competition and predation
What is a niche
Describes how an organisms fits into its environment and refers to where an organism lives and what it does there
Includes the role of that an organism plays in the ecosystem and its biotic (living) and abiotic (non-living) interactions
What is the competitive exclusion principle
Different organsims will have different niches within the same habitat
2 different species try to occupy the same niche, one will be out-competed by the other until one species survives
To increase their chances of survival, organsims will be adapted to their niches
Give some example software limiting factors
Availability of food, light, watermelon oxygen, shelter
Accumulation of toxic waste, disease and predators
What is interspecific competition
Competition for the same resources between organisms of different species within the same habitat or niche
What is intraspecific competition
Competition between organisms of the same species for the same resources
What is the effect of predator- prey relationships on population
Predator eat prey - reduce population size
With fewer prey available, the predators are in greater competition, the predator population is reduced and therefore fewer prey are eaten, so more survive and reproduce
What is conservation
Management of the earths natural resources by humans in such a way that maximum use of them can be mad in the future
What are the reasons for conservations
Personal - maintain our planet and our life-support system
Ethical
Economic -living organism contain a large pool of genes with the capacity to make many substances
What is ecological succession
Directional change in the composition of species that occupy a given area through time- it involves initial colonisation and establishment of the plant pioneer species, followed by replacement of other species until relatively stable community is formed
What is a climax community
Communities tend to remain stable over a long period of time
Describe primary succession (5 marks )
- Empty habitat in a harsh environment
- Habitat colonised by pioneer plant species- modify environment creating conditions that support new species- making it less hostile by the formation of soil or organic matter and increase in nutrients
- Enables other species to store colonise and survive changing the biodiversity as new plant species are established and various groups of animals enter the habitat
- Organsims which are best adapted will out compete and replace those
- Stability increases before reaching a climax community
What are ways conservation cna be controlled
Grazing livestock
Controlled fires
Fishing quotas
Protecting land
Captive breeding
Seed bank
What is sex linkage
Genes for certain characteristics are carried on the sex chromosomes
What is autosomal linkage
If two or more genes are located on the same chromosome
What is epistasis
When the allele of one gene affects or masks the expression of another allele in the phenotype
