Chapter 3, Problem 4A

Summary Introduction

Introduction:

In an ecosystem, the effects of abiotic factors are very important for the survival of species. The limiting factors are the abiotic factors that may limit the growth of population after a certain number. Tolerance factor is the measurement of the range in which a particular organism can easily survive.

Answer to Problem 4A

Correct Answer:

Option (c) Limiting factor.

Explanation of Solution

Explanation/justification for the correct answer:

Option (c) limiting factor. The limiting factor is the abiotic factor that limits the growth or the survival of the organism after a certain number. In this case, where the amount of iron determines the population size of the organism, the iron acts as a limiting factor.

Explanation for incorrect answer:

Option (a) distribution. The distribution factors can be described as the factor affecting the presence or absence of an organism in an ecosystem. Most of the organism prefer to live in the region, where resources are abundant, here the iron is abundant throughout the zone, but it is not controlling the dispersion. Hence, this is an incorrect option.

Option (b) tolerance. The tolerance factor measures the range of an abiotic factor that can be tolerated by the organism. All the organism if present in a intolerable zone, they would die, it does not control the population. Hence, this is an incorrect option.

Option (d) biotic. The biotic factors are the living things affecting the survivability of the organism. Here, iron is not a biotic factor. Hence, this is an incorrect option.