Question

Which of the following is not a feature of a J-shaped growth form of the population?
A. It is found in a stable type of population.
B. The exponential phase is very rapid.
C. A crash phase occurs at the end of the growth.
D. Environmental resistance does not operate.

Answer 1

Hint: The population growth curve is the graphical representation of the population that shows how a particular quantity of population increases over time. The J-shaped indicates that there is a large growth of population due to the presence of unlimited resources. this curve initially falls and then afterwards rises above the starting point.

Complete answer:
> A curve on a graph that records a situation in which the organism population density increases rapidly in an exponential or logarithmic form in a new environment, but stops immediately because environmental resistance and some other factors rapidly become effective. This type of growth curve is termed a J-shaped growth curve.
> Biotic potential and population size are the two factors on which the actual rate of population change depends.
> dN/dT = rN
Here N is the number of individuals in the population, t is time and r is the rate constant that represents the increased intrinsic rate of the organism concerned.
> The growth of the population is exponential and after achieving the peak value, the population may crash rapidly.
> There is a continuous increase in the population until a large number of food materials are available in the habitat.
> The exponential phase is very rapid due to the presence of unlimited resources.
A crash phase occurs due to the immediate decline in the population size because of mass-scale deaths.
> Due to the environmental resistance growth stops abruptly.

Hence, the correct answer is option A.

Additional Information:
J-shaped growth curve shows only exponential growth, so known as an exponential growth curve.
The S-shaped growth curve is sigmoid.
Exponential growth takes place when the growth of the population slows and then stops.
The J-shaped growth curve shows an immediate increase in the population growth as each generation produces more offsprings.

Note:
In the J-shaped growth curve, the growth of the population is exponential and after achieving the peak value, the population may crash rapidly. The increase in the population growth is continued only till a large quantity of food is present in the habitat. The exponential phase is very rapid due to the presence of unlimited resources. After some time, food supply becomes limited and population size declines.