Question

Which of the following statement(s) is are correct?

(1) In a population growth rate curve, the lag phase represents the period when a population is adjusting to a new environment

(2) In a population growth rate curve, the steepest part of growth phase represents the period when a population is growing exponentially

(3) In the stationary phase of a population growth rate curve the population is in dynamic equilibrium

(4) Human have changed the carrying capacity of the earth

• A.
  All of these
• B.
  (1), (2) and (3)
• C.
  (2) and (3)
• D.
  (1) and (4)

Answer 1

The correct option is A

All of these
Population growth is the increase in the number of people in a population. The human population growth curve is S-shaped or sigmoid. It has three phases:

(a) Lag phase is slow in the beginning due to small size of population, lack of adaptation to new environment and slow development

(b) Log phase or exponential phase is the geometric increase in population size due to abundance of food, space and natural resources.

(c) Stationary phase or zero growth phase is the stability of population, i.e., birth and death rates are equal, so that there is no growth in population size.

The carrying capacity of the planet for humans has increased over time, especially with the development of agriculture and other technologies. The industrial revolution has only artificially increased our carrying capacity since it is based on the use of fossil resources, and thus is not indefinitely sustainable.

So, all of the statements are correct.