Organisms and Populations Question 43
43. When does the growth rate of a population following the logistic model equal zero ? The logistic model is given as $dN / dt=rN(1-N / K)$
(a) when $N / K$ is exactly one.
(b) when $N$ nears the carrying capacity of the habitat.
(c) when $N / K$ equals zero.
(d) when death rate is greater than birth rate.
Show Answer
Answer : a
Hints & Solutions
(a) In logistic growth model population growth equation is described as $\frac{dN}{dt}=rN(1-\frac{N}{K})$ $N=$ population density at time $t$; $r=$ Intrinsic rate of natural increase; $K=$ carrying capacity When $N / K=1 ; 1-\frac{N}{K}=0$ Therefore, $\frac{dN}{dt}=0$ Studying population growth also helps scientists understand what causes changes in population sizes and growth rates. Studying population growth gives scientists insight into how organisms interact with each other and with their environments.
