Chapter 10, Problem 1STP

Summary Introduction

Introduction:

An important feature of any population is its growth rate. The population growth rate or the PGR explains how fast a given population grows. Many factors affect the PGR like the birth rate, mortality rate, emigrating rate, immigrating rate etc. some populations grow slowly while some show exponential growth.

Answer to Problem 1STP

Correct answer :

The correct answer is option A. below the main reproductive age

Explanation of Solution

Explanation/justification for the correct answer:

Option A. below the main reproductive age − A population will enter a long term high growth rate when the individuals are just below the main reproductive age because the total number of organisms that are able to reproduce soon increases. Hence this is the correct option.

Explanation for incorrect answer:

Option B. just above the main reproductive age− If large numbers of individuals are just above the main reproductive age the population will soon start to decline as the birth rate will fall. New offspring will not be produced and the population will consist of aging individuals.

Hence, this is not the correct option.

Option C. at the middle of the main reproductive age- If more individuals are at the middle of the main reproductive age the population will not increase in long term as more individuals will soon enter non- reproductive age. Very few new individuals will be added to the population. Hence, this is not the correct option.

Option D. at the upper end of the main reproductive age− If more individuals are at the upper end of the main reproductive age, the population will not increase in long term as all individuals will soon enter non- reproductive age. No new individuals will be added to the population. Hence this is not the correct option.