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11 Cards in this Set
- Front
- Back
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What is interspecific variation? |
When one species differs from another |
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What is intraspecific variation? |
When members of the same species differ from each other |
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Why might the measurements taken during sampling no be representative of the whole population? |
1. Sampling bias Investigators make unrepresentative choices 2. Chance Individuals may make an unrepresentative choice by pure chance even when bias has been avoided |
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How can sampling bias be avoided? |
Random sampling 1. Divide stud area into a grid of numbered lines 2. Using a random number generator on a computer, obtain a series of coordinates 3. Take samples at the intersection of each pair of coordinates |
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How can chance be minimised? |
1. Using a large sample size The greater the sample size, the more reliable the data will be 2. Analysis of the data collected Determines the extent to which chance may influence the data |
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How does genetic variation arise? |
1. Mutations 2. Meiosis 3. Sexual reproduction |
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What two factors result in variation? |
1. Genetic differences 2. Environmental influences |
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Name some examples of environmental influences |
1. pH 2. Food availability 3. Temperature 4. Rainfall 5. Sunlight |
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What is a mean? Why is a mean calculation useful? Why may the mean not be useful?
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The average value Useful when comparing one sample with another Does not provide any information about the range of values within the sample |
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What is standard deviation?
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Gives an indication of the range of values either side of the mean
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How do you calculate standard deviation? |
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