Question

The population of an insect species shows an explosive increase in numbers during rainy season followed by its disappearance at the end of the season. What does this show ?

• A. The population of its predators increases enormously
• B. S - shaped or sigmoid growth of this insect
• C. The food plants mature and die at the end of the rainy season
• D. Its population growth curve is of J-type

Answer 1

The correct option is D Its population growth curve is of J-type

The population of an insect species that shows an explosive increase in numbers during rainy season followed by its disappearance at the end of the season follows a J-type growth curve.
J-shaped growth curve is a graph that records the situation in which, in a new environment, the population density of an organism increases rapidly in an exponential or logarithmic form, but then stops abruptly as environmental resistance (e.g. seasonality) or some other factor (e.g. the end of the breeding phase) suddenly becomes effective. The actual rate of population change depends on the biotic potential and the population size.
It may be summarized mathematically as: dN/dt = rN (with a definite limit on N) where N is the number of individuals in the population, t is time, and r is a constant representing the intrinsic rate of increase (biotic potential) of the organism concerned.