Name the population growth pattern the equation
rN
dt
dN
represents. What does ‘‘r’’ represent in the equation ? Write its
importance in population growth.

Exponential Growth − When the resources are unlimited, population tends to grow in an exponential pattern.

If the population size is N and the birth and death rates (not per capita) are b and d respectively, then increase or decrease in N at t (time period) is given by,

dN /dt = (b − d) × N
If (b − d) = r, then
dN/ dt = rN
r is the “intrinsic rate of natural increase”.
The 'r' means intrinsic rate of natural increase. It is a measure of the instantaneous rate of change of population size.
Increase in value of r (when the value of r is positive) indicates that the population size of a species has increased during the particular period. Decrease in value of r (when the value of r is negative) indicates that the population size of a species has decreased during the particular period.