Question

Assertion : A population growing in a habitat with limited resources shows initially a lag phase, followed by phases of acceleration and deceleration and finally an asymptote, when the population density reaches the carrying capacity.
Reason : In Verhulst-Pearl Logistic growth, plot of $N$ (population density) at time $(t)$ results in a sigmoid curve

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (B)

A population growing in a habitat with limited resources shows initially a lag phase, followed by phases of acceleration and deceleration and finally an asymptote, when the population density reaches the carrying capacity.
A plot of population density $(N)$ in relation to time $(t)$ results in a sigmoid curve. This type of population growth is called Verhulst-Pearl Logistic Growth and is described by the following equation :
$\frac{dN}{dt}=rN\left(\frac{K-N}{K}\right)$
Where $N=$ Population density at time $t$
$r=$ Intrinsic rate of natural increase
and $K=$ Carrying capacity.