Lesson 5 of 13 · 6 min
Absolute and relative growth rate
NCERT §13.1.4
Kavya's young tea leaf and a big mature leaf each gain the same area in a week. Her cousin says they grew equally. Are they right?
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The lesson in notes
In short
Growth of two living systems can be compared in two ways.
Absolute growth rate: the total growth per unit time, measured and compared as it is.
Relative growth rate: growth per unit time expressed on a common basis, for example per unit of the initial parameter.
Two leaves of different sizes, A and B, may each gain 5 cm² of area in the same time. Their absolute growth rates are equal, but the smaller leaf has the much higher relative growth rate, because 5 cm² is a larger fraction of its starting area.