Chapter 15, Problem 2STP

Summary Introduction

Introduction:

Charles Darwin gave a theory of natural selection. He argued that if enough time is given, natural selection could modify a population to produce new species. There are four principles of this theory.

1. Individuals in a population show differences called variations.
2. Variations can be inherited, i.e., they can be passed down from parent to offspring.
3. Organisms produce more offspring than can survive on available resources.
4. Variations that increase reproductive success will have a greater chance of being passed on than those that do not increase reproductive success.

Answer to Problem 2STP

Correct answer :

The correct answer is option B. variation.

Explanation of Solution

Explanation/justification for the correct answer:

Option B. variation−On the Galapagos Islands, Darwin studied many species of animals and plants that were unique to the islands but similar to species elsewhere. According to the illustration given below, the two tortoises in different islands differ in their body size and shape. So, it can be clearly seen that the tortoises have variations. Hence, this is the correct option.

Explanation for incorrect answer:

Option A. inheritance− According to the illustration given below, the two tortoises in different islands differ in their body size and shape. So, it can be clearly seen that the tortoises have variations. The illustration does not say or depict anything about inheritance. Hence, this is not the correct option.

Option B. differential reproduction- According to the illustration given below, the two tortoises in different islands differ in their body size and shape. So, it can be clearly seen that the tortoises have variations. The illustration does not say or depict anything about differential reproduction. Hence, this is not the correct option.

Option D. overproduction of offspring − According to the illustration given below, the two tortoises in different islands differ in their body size and shape. So, it can be clearly seen that the tortoises have variations. The illustration does not say or depict anything about overproduction of offspring. Hence, this is not the correct option.