Chapter 4, Problem 6STP

Summary Introduction

Introduction :

Any population grows exponentially when resources are abundant and density-dependent factors such as competition, disease, predation, and parasites are not effective enough to slow down the population growth. Human population growth depends upon Birth rate, Death rate, Immigration, and Emigration.

Answer to Problem 6STP

Correct answer :

The correct answer is option (D) plowing and irrigation.

Explanation of Solution

Explanation/justification for the correct answer :

In reference to the given graph, it is clear that plowing and irrigation activity coincides with the gradual increase in the human population becoming one of the milestones in the human population growth. These activities ensured the availability of plenty of food sources to humans and, hence death rate started to decrease.

Explanation for incorrect answer :

Option (A) Bubonic plague: In the period of 1347A.D. to 1350 A.D., one-third of the European population died of Bubonic plague outbreak. This caused a sharp dip in human population growth.

Option (B) Farming activity ensured the supply of food for humans but the Human population was almost static in the New Stone age.

Option (C) Industrial revolution in the Middle age gave a boost to population growth, and the population started to grow exponentially.