Chapter 3, Problem 2A

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 2A

Correct term:

Limiting factor.

Explanation of Solution

Explanation/justification for the correct answer:

The limiting factor is the abiotic factor that limits the growth or the survival of the organism after a certain number. The amount of oxygen in a closed system like fish tank is limited. Hence, it is sufficient for a limited number of fish to survive, which means oxygen in the fish tank is a limiting factor.

Explanation for incorrect answer:

The tolerance zone in this case is the oxygen saturation. The fishes cannot tolerate change in the oxygen saturation level. In this case, the amount of oxygen is the reason of decreased survival of the species. Hence, it is not a tolerance factor.

Conclusion

Hence, the amount of oxygen in the tank is the limiting factor that affects the total number of fishes that can survive in the tank.