7-Genetics,Population,Ecosystem Flashcards
What’s a community
Populations of different species in the same area at the same time
What’s a population
Group of organisms of the same species in the same habitat at a particular time that can interbreed
What’s a habitat
Part of an ecosystem where organisms live
What’s an ecosystem
A community and the non living components of an environment
What’s a niche
Organisms role within an ecosystem
What’s carrying capacity
Maximum population size an ecosystem can support
What are abiotic factors
Non living conditions
Biotic factors
Impact of interactions between organisms
What factors affect population size
Abiotic factors
Plants and animals adapted to abiotic factors in an ecosystem through natural selection, if abiotic factors are less harsh population size increases
Biotic factors interspecific competition (individuals of different species compete), infraspecific competition (individuals of the same species compete), predation (always more prey than predators, changes occur in prey then predators)
How can population be estimated
Quadrats randomly placed/along a line transect for non moving organisms
Mark release recapture
What are assumptions made during mark release recapture
There are no births, deaths or migration
The marking isn’t rubbed off during investigation
The animals are given enough time to distribute themselves evenly
Ecological succession
Change in ecological community over time
What’s primary succession
Pioneering species eg lichen colonise bare rock/sand, lichen decompose sufficient nutrients in soil causing moss to grow then fern, rock eroded and more decomposition creates a thicker layer of soil, grass shrubs and trees grow as they outcompete previous species, created complex food webs with pots of biodiversity creating a climax community
What’s secondary succession
Plants are destroyed from a disruption like a wild fire
Succession starts from soil, seeds remain alive, faster than primary
Conservation of habitats
Destruction occurs from human activity causing food loss/space leading to extinction
By maintaining earlier stages of succession a greater variety of habitats are conserved. Conflict between human needs and conservation need to be managed eg coppicing trees for timber
