BRAINCAKESampling
It is usually impossible to count or measure every individual in a population, so biologists take a sample. The sample is used to estimate the characteristics of the whole population.
A sample must be representative of the population. If it is not, any conclusions drawn from it may not be valid.
Sampling bias happens when the investigator, consciously or not, chooses individuals that are not typical, for example the largest plants or the most accessible areas. Bias is reduced by using random sampling.
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Key terms in this lesson
- random sampling
- A method of sampling in which every individual or position within the area studied has an equal chance of being selected, which removes sampling bias.
- genetic diversity
- The variety of alleles present within the gene pool of a population or species.
More in Biodiversity
- Investigating Diversity
- Comparing DNA
- Comparing mRNA
- Comparing Amino-acids Sequences
- Random Sampling
- Normal Distribution
- Mean, median and Mode
- Mean and Standard Deviation
All 33 lessons in Biodiversity · All AQA AS-level Biology topics