A population growing in a habitat with limited resources passes through the following phases:
A. Deceleration
B. Lag phase
C. Asymptote, when the population density reaches the carrying capacity
D. Acceleration
Arrange the phases in the order in which they occur. Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → B, D, A, C
A habitat with limited resources can support only a maximum number of individuals, its carrying capacity (K). Such a population shows logistic growth, and its plot of N against time is a sigmoid (S-shaped) curve.
First – B. Lag phase: At the start there are few individuals, so numbers rise slowly.
Second – D. Acceleration: As more individuals breed, the population grows faster and faster.
Third – A. Deceleration: As the population nears K, resources become limiting and competition increases, so the growth slows down.
Fourth – C. Asymptote: The population density reaches the carrying capacity, and no further growth is possible. The curve levels off.
NCERT Extract:
Growth Models – “… In nature, a given habitat has enough resources to support a maximum possible number, beyond which no further growth is possible. Let us call this limit as nature’s carrying capacity (K) for that species in that habitat. A population growing in a habitat with limited resources show 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 N in relation to time (t) results in a sigmoid curve.”