Chapter 16, Problem 1TY

Which of the following is an example of an epigenetic change that alters gene expression?

1. chromatin remodeling
2. covalent histone modification
3. localization of histone variants
4. DNA methylation
5. all of the above

Summary Introduction

Introduction:

Epigenetic is referred to as the study of heritable alterations in the gene expression that does not include any change to the underlying deoxyribonucleic acid (DNA) sequence.

Answer to Problem 1TY

The correct answer is option (e) all of the above.

Explanation of Solution

Explanation for the correct answer:

Option (e) all of the above. The examples of epigenetic alterations include DNA methylation, chromatin remodeling, covalent histone modification, and localization histone. In the case of chromatin remodeling, the changes in the architecture of chromatin can prevent the expression of some specific genes. So, the correct answer is option (e).

Explanation for incorrect answer:

Option (a) chromatin remodeling. Chromatin remodeling is one of the examples of epigenetic change. However, DNA methylation also affects certain gene expression. So, this is an incorrect option.

Option (b) covalent histone modification. Histone functions in packaging the DNA into structural units known as nucleosomes. The histone modification can prevent the expression of a gene. Moreover, chromatin remodeling also affects the expression of certain genes. So, this is an incorrect option.

Option (c) localization of histone variants. The localization of histone variants affects the readability of the DNA by the cell. However, DNA methylation and chromatin remodeling also affect gene expression. So, this is an incorrect option.

Option (d) DNA methylation. The addition of the methyl group to the portion of DNA affects the expression of certain genes. However, the other examples of epigenetic alteration are chromatin remodeling, localization of histone variants, and covalent histone modification. So, this is an incorrect option.