Read Growth from r to Carrying Capacity
Population growth depends on intrinsic increase, resource limits, environmental resistance and movement.
Population Growth is the central idea in this question pattern. Identify the condition in the stem before applying the method below.
Compare the models
N approaches K and the curve is sigmoid.
Account for change
Population change includes births and immigration, minus deaths and emigration. Per-capita rates determine r; if conditions or resources constrain growth, the population may level off or crash.
Read the evidence
At the logistic asymptote, population size stabilises near K. Net change from rates is applied to the current population to estimate the next time step.
Density dependence in a fixed resource patch
Bush-fly larvae share a fixed volume of dung. As egg density rises, the fraction surviving falls because food and space are limited. Total adult emergence therefore tends toward a resource-limited level for dung cakes of similar volume; it is not a universal fixed number across cakes of every size.
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- ✓Exponential: dN/dt=rN; J-shaped.
- ✓Logistic: dN/dt=rN(1−N/K); S-shaped.
- ✓Net change = births + immigration − deaths − emigration.
- ✓At carrying capacity, net growth approaches zero.
- ✓Increasing density can reduce per-capita survival.
- ✓A similar resource-patch size can support a similar total yield.
One unlinked question refers to missing growth-curve labels, so this read covers 6 of 7 assigned questions (86%).
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