Chapter 14, Problem 1SQ

Summary Introduction

Introduction: The evolution of an organism occurs due to the changes in the genetic makeup of a population that takes place from generation to generation. These changes help an organism and its generation to survive the changing environments and harsh conditions. Genetic variation occurs due to mutations, genetic drift, natural selection, and gene flow.

Answer to Problem 1SQ

Correct answer: “In natural selection, individuals that possess particular inherited characteristics consistently survive and reproduce at a higher rate than other individuals”. Hence, the correct answer is option d.

Explanation of Solution

Reasons for the correct answer:

Darwin proposed that the process of natural selection was the cause of evolution in species. He explained that the different species were able to survive nature’s harsh conditions and limited resources due to adaptations. The species that were successful in surviving were selected by nature. Nature selected adaptive traits that are then passed on to the offspring that help a species to survive and show adaptive radiation, according to different habitats.

Option d. is given as “individuals that possess particular inherited characteristics consistently survive and reproduce at a higher rate than other individuals”.

Natural selection is the cause of evolutionary change that promotes adaptation. A population adapts itself to survive various conditions. The adaptability can occur due to some traits which help them to survive.

Hence, the correct answer is option d.

Reasons for the incorrect answers:

Option a. is given as “the genetic composition of the population changes randomly over time”.

In natural selection, the genetic composition of the population does not changes randomly over time.

Hence, option a. is incorrect.

Option b. is given as “new mutations are generated over time”.

In natural selection, new mutations are not generated over time.

Hence, option b. is incorrect.

Option c. is given as “all individuals in a population are equally likely to contribute offspring to the next generation”.

This is a condition of the Hardy-Weinberg equilibrium and not natural selection.

Hence, option c. is incorrect.

Therefore, options a., b., and c. are incorrect.

Conclusion

Natural selection is a process where an organism survives an adverse condition by adapting to it. It results in differential survival and reproduction of individuals in a given population due to environmental pressures.