Chapter 22, Problem 1TY

Summary Introduction

Introduction: A group of organisms, which are related and share a distinctive form, is known as species. Members of the species living in a particular area at a particular time, which are capable of interbreeding, are known as a population. The population keeps changing to produce new species over time.

Answer to Problem 1TY

Correct answer: A change in one or more than one characteristic of a population, which can be transferred over several generations, is known as evolution. Hence, the correct answer is option d.

Explanation of Solution

Reason for the correct answer:

Evolution refers to the changes in one or more characteristics of a given population which can be inherited by the next generation. Genetic variation and natural selection are the two main factors causing evolution. The theory of evolution was given by Charles Darwin. A gradual change in related species over time forms the basis of the theory of evolution.

Option d. is given as “evolution”

Changes in one or more characteristics of a population, which can be inherited over various generations through time, are known as evolution. Hence, the correct answer is option d.

Reasons for the incorrect answer:

Option a. is given as, “natural selection”.

Individuals having characteristics that are more suitable for a particular environment are able to survive and reproduce successfully. These individuals are naturally selected and thus, evolution is caused. Therefore, natural selection is one of the factors which cause evolution. Hence, option a. is incorrect.

Option b. is given as, “sexual selection”.

A form of natural selection is known as sexual selection. Sexual selection refers to a process through which individuals with particular traits engage in a successful mating event with individuals of the opposite sex over other individuals belonging to the same sex. Sexual selection is a factor affecting natural selection and evolution. Hence, option b. is incorrect.

Option c. is given as, “population genetics”.

The study of genetic differences present in a population by studying genes and genotypes is known as population genetics. The population genetics makes up a part of evolutionary biology. It is a study and is not responsible for causing changes in the characteristics of the given population. Hence, option c. is incorrect.

Option e. is given as, “inheritance of acquired traits”.

According to Lamarck’s theory, organisms change their behavior according to the changes in the environment. Therefore, the inheritance of acquired characteristics is based on Lamarck’s theory which was rejected as research depicted that most of the acquired traits could not be inherited. Hence, option e. is incorrect.

Hence, the options a., b., c., and e. are incorrect.

Conclusion

Thus, evolution refers to the changes in characteristics of the population which are inherited over time.