(a) Name the two growth models that represent population growth and draw the respective growth curves they represent.
(b) State the basis for the difference in the shape of these curves.
(c) Which one of the curves represent the human population growth at present? Do you think such a curve is sustainable ? Give reason in support of your answer.

Explanation

The two growth models are :
1. Logistic growth
2. Exponential growth
(b) The difference in growth curves is due to the difference in availability of resources. In logistic growth the resources available are limited resulting in a sigmoid curve. In exponential growth the resources are unlimited resulting in a J shaped curve.
(c) The human population growth is represented by the exponential growth curve. The curve is not sustainable become sooner or later resource (food and space ) it self becomes limiting for the vast population leading to a logistic growth pattern