AQA B2 2.4 Organisms and their environment

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  • Created by: Rchilds
  • Created on: 30-05-17 12:53
Which physical factors may effect an organism?
temperature; availability of nutrients; amount of light; availability of water; availability of oxygen and carbon dioxide
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How can quantitative data on the distribution of organisms be obtained?
random sampling with quadrats or sampling along a transect.
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How does sampling with quadrats work?
A metal square is placed RANDOMLY in a sample area e.g. by rolling dice to decide where to put it, this avoids BIAS. Organisms in the square are counted. Calculate and average for a square and multiply up to estimate the total organisms in the area
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How can you make the results from quadrat sampling more valid and reproducible?
Take more quadrat samples or use bigger squares. Wait until plants are bigger so you are less likely to miss them.
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How does sampling along a transect work?
A transect is a line across a habitat or part of a habitat e.g. a string or rope placed in a line on the ground. The number of organisms of each species can be observed and recorded at regular intervals along the transect using a quadrat
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When are transects more useful than random quadrats?
When you need data on the number of organism with relation to another factor e.g. distance from river/shore
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How do you calculate a percentage?
(Your sample divided by the total amount from all samples) x 100
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Other cards in this set

Card 2

Front

How can quantitative data on the distribution of organisms be obtained?

Back

random sampling with quadrats or sampling along a transect.

Card 3

Front

How does sampling with quadrats work?

Back

Preview of the front of card 3

Card 4

Front

How can you make the results from quadrat sampling more valid and reproducible?

Back

Preview of the front of card 4

Card 5

Front

How does sampling along a transect work?

Back

Preview of the front of card 5
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