Q: Which of the following equations best represents the relationship between DNA, nucleosomes, and chromatin?

$$\text{DNA} + \text{Histones} \rightarrow \text{Nucleosome} \rightarrow \text{Chromatin}$$

Question 1

Which of the following best describes the structure shown in the first image (the double helix)?

Accepted Answer

A nucleic acid composed of two antiparallel strands forming a double helix

Question 2

What is the primary function of histone proteins in eukaryotic cells, as illustrated in the second image?

Accepted Answer

To package and organize DNA into nucleosomes

Question 3

Which of the following statements about chromatin structure is correct?

Accepted Answer

Euchromatin is loosely packed and associated with active transcription

Question 4

Refer to the third image. What is the correct order of DNA packaging from least to most condensed?

Accepted Answer

DNA double helix → Nucleosome → 30-nm fiber → Chromatid

Question 5

What is the effect of histone acetylation on chromatin structure and gene expression?

Accepted Answer

It loosens chromatin and promotes gene expression

Question 6

Which chemical modification is most likely to result in gene silencing, as shown in the fifth image?

Accepted Answer

Addition of methyl groups to DNA bases

Question 7

A researcher observes that a gene is not expressed in a particular cell type. The chromatin in this region is highly condensed. Which term best describes this chromatin?

Accepted Answer

Heterochromatin

Question 8

Which of the following best explains why identical twins can have different patterns of gene expression as they age, as shown in the last two images?

Accepted Answer

Their epigenomes change in response to environmental factors

Question 9

Which process is described by the inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence?

Accepted Answer

Epigenetic inheritance

Question 10

If a cell undergoes DNA methylation in a gene promoter region, what is the most likely outcome for that gene?

Accepted Answer

The gene will be silenced

Question 11

Which of the following equations best represents the relationship between DNA, nucleosomes, and chromatin?

Accepted Answer

$$	ext{DNA} + 	ext{Histones} ightarrow 	ext{Nucleosome} ightarrow 	ext{Chromatin}$$

Question 12

A scientist treats cells with a drug that prevents acetylation of histone tails. What is the most likely effect on gene expression?

Accepted Answer

Gene expression will decrease due to tighter chromatin

Question 13

Which of the following best describes the role of the N-termini (tails) of histones?

Accepted Answer

They are sites for chemical modifications that regulate gene expression

Question 14

Which of the following is a direct consequence of DNA methylation during DNA replication?

Accepted Answer

The methylation pattern is copied to the daughter strands

Question 15

Which of the following scenarios best illustrates epigenetic inheritance?

Accepted Answer

A methylation pattern on DNA is passed to daughter cells during cell division

Question 16

Which of the following best explains why genes in heterochromatin are usually not expressed?

Accepted Answer

The DNA is highly condensed, making it inaccessible to transcription machinery

Question 17

Which of the following is NOT a feature of nucleosomes?

Accepted Answer

They are found only in prokaryotic cells

Question 18

A cell is observed to have a high level of acetylated histones in a particular region of its genome. What can you infer about this region?

Accepted Answer

It is likely to be transcriptionally active

Question 19

Which of the following best describes the relationship between the environment and the epigenome?

Accepted Answer

The environment can influence which genes are expressed by modifying the epigenome

Question 20

Which of the following is a correct statement about the inheritance of epigenetic tags?

Accepted Answer

Epigenetic tags can sometimes be passed to offspring, affecting gene expression in the next generation

Chromatin Structure, Epigenetics, and Regulation of Gene Expression

Study Guide - Practice Questions

Study Guide - Flashcards