organisms and their environment: distribution of organisms
- Created by: geogt002
- Created on: 31-05-16 11:49
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- organisms and thier environment:distrubutiion of organisms
- distribution may be affected by physical factors.
- transects and quadrats collect quantitative data about organisms in their habitat.
- mean , median and mode can then be found from this set of data.
- usually not possible to count entire population of a particular organism in a habitat.
- must be sampled instead.
- transects
- A line across a habitat or part of a habitat. can be string or rope. number of organisms of each species can be observed and recorded at several intervals throughout the transect.
- Quadrats
- a square mad of wire-usually.. may have more quares in centre to makk of smaller aread. anything unernath the quadrat can then be identified and counted.
- should be placed randomly so that a representive example s taken.
- the validlicy and reproducabiltyof the resuts increase as the results from more quadrats are produced.
- used for slow moving aniimals. e.g. slugs and snails.
- a square mad of wire-usually.. may have more quares in centre to makk of smaller aread. anything unernath the quadrat can then be identified and counted.
- physical factors
- tempreture
- amount of light
- avalibilty of water
- avaiblitly of nutrients
- availability of oxygen and carbon dioxide.
- predators
- e.g. daisy plants need more light from the sun in order to make food and complete photodsynthisis. this means that they will be found in light not shady places
- light ENERGY
- E.G. grass is found in sunlight of a filed rather than in semi shaded area or woodland. this is because grass needs a lot of light energy to photosynthisise.
- ecosystems
- environment- all the conditions that surround a living organism.
- habitata- the pace in which an organism lives.
- population- all the members of a single species that live in a habitat.
- communtity- all the poupulations of differnt organisms that live together in a habitat.
- ecosystem- acommuntiy and the habitat in whcih it live sin.
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