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Biology · Variation · Continuous vs discontinuous
Continuous vs discontinuous variation
Generate a sample of students and measure two traits: height (any value possible — continuous) and tongue-rolling ability (you can or you can't — discontinuous). The two shapes of distribution tell you which kind of variation you're dealing with.
n = 0
Key differences
| Continuous | Discontinuous | |
|---|---|---|
| Values | any along a range | distinct categories |
| Plot | histogram | bar chart |
| Distribution | bell curve (normal) | discrete bars |
| Genes | many (polygenic) | one or few |
| Environment | major influence | little / none |
| Example | height, mass | blood group, tongue roll |
Exam-style questions
1. Height is an example of which TYPE of variation?
2. Tongue-rolling ability is an example of which TYPE of variation?
3. Which is the CORRECT type of graph for plotting CONTINUOUS variation in a population?
4. Continuous variation in height usually has BOTH genetic and environmental causes. Which environmental factor is MOST relevant?