Variation
Variation means differences among individuals of the same species.
Practice This ConceptMain explanation
Teacher explanation
Variation is the reason siblings are not exactly alike. Some differences are inherited from parents, while others are caused by environment such as nutrition, light, or climate. Variation is important because it gives a population a chance to survive if conditions change, and it also provides the raw material for evolution.
Example
Two brothers may have different heights, skin tones, or hair textures. In plants, two seedlings of the same species may grow to different sizes because of different light or water supply.
Simple analogy
Variation means same species, different features.
Common confusion
Students often think all differences are due to heredity alone. In reality, both genes and environment can produce variation.
Exam tip
When answering, separate inherited variation from environmental variation. This makes your answer more complete and more accurate.
Answer writing and exam use
1-mark use
Write the exact meaning of variation in one clean line.
2-mark use
Define variation and add one example or condition.
3-mark use
Explain variation, show the method or example, and mention the common mistake.
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