Populations and Communities · Paper 1 — Free Biology SL Practice Questions

A population of bacteria is cultured in a closed flask containing a fixed amount of glucose. The graph shows logistic growth of the population over time, with four regions labelled A–D. $$\begin{array}{c}\text{}\end{array}$$ In which region is the per capita growth rate, $r$, at its maximum?

A population of yeast cells is cultured in a closed vessel containing a fixed amount of glucose. The population grows exponentially at first, then growth slows, and finally the population stabilises at carrying capacity $K$. According to the logistic growth model, at which stage is the per capita growth rate highest?