Question 1

Which of the following best describes the structure of a nucleosome in eukaryotic cells?

Accepted Answer

A segment of DNA wound around a core of eight histone proteins

Question 2

During which phase of the cell cycle does chromatin become most condensed, forming visible metaphase chromosomes?

Accepted Answer

Metaphase

Question 3

Which property distinguishes heterochromatin from euchromatin?

Accepted Answer

Heterochromatin is more densely packed and generally transcriptionally inactive

Question 4

What is the primary function of histone proteins in the cell nucleus?

Accepted Answer

To package and organize DNA into structural units called nucleosomes

Question 5

If the DNA in a human cell was stretched out, it would measure about 2 meters in length. Which mechanism allows this DNA to fit inside the nucleus?

Accepted Answer

DNA is wound around histones to form nucleosomes, which are further coiled and folded into higher-order structures

Question 6

Which of the following equations best represents the relationship between the number of nucleosomes ($$n$$), the length of DNA ($$L$$), and the average number of base pairs per nucleosome ($$b$$)?

Accepted Answer

$$n = \frac{L}{b}$$

Question 7

A mutation causes a cell to produce histones that cannot be chemically modified. What is a likely consequence of this mutation?

Accepted Answer

The cell may lose the ability to regulate chromatin condensation and gene expression properly

Question 8

Which of the following best explains why bacterial chromosomes differ from eukaryotic chromosomes?

Accepted Answer

Bacterial chromosomes are typically circular and have fewer associated proteins

Question 9

During which stage of mitosis do condensin proteins play a major role in further compacting chromatin into visible chromosomes?

Accepted Answer

Prophase

Question 10

A scientist observes that a certain region of DNA is highly condensed and not transcribed. This region is most likely:

Accepted Answer

Heterochromatin

Question 11

Which of the following scenarios best illustrates the dynamic nature of chromatin structure?

Accepted Answer

Chromatin becomes more condensed during mitosis and less condensed during interphase

Question 12

Which of the following is a functional consequence of euchromatin being less condensed than heterochromatin?

Accepted Answer

Genes in euchromatin are more likely to be actively transcribed

Question 13

If a eukaryotic cell failed to produce enough histone proteins, what would be the most immediate effect on its DNA?

Accepted Answer

The DNA would be less compact and more susceptible to damage

Question 14

Which of the following best describes the role of condensin proteins during mitosis?

Accepted Answer

They help further coil and compact chromatin into metaphase chromosomes

Question 15

A researcher is studying a gene that is highly expressed in liver cells but not in skin cells. Which chromatin state is this gene most likely found in within liver cells?

Accepted Answer

Euchromatin

Question 16

Which of the following statements about nucleosomes is correct?

Accepted Answer

Each nucleosome consists of DNA wrapped around a histone octamer

Question 17

Which process is most directly affected by the chemical modification of histone tails?

Accepted Answer

Regulation of gene expression

Question 18

Which of the following best explains why metaphase chromosomes are shorter and thicker than interphase chromatin?

Accepted Answer

Chromatin undergoes multiple levels of coiling and folding, resulting in highly condensed metaphase chromosomes

Question 19

Which of the following is a real-world consequence of improper chromatin condensation during cell division?

Accepted Answer

It can lead to chromosome missegregation and genetic disorders such as Down syndrome

Chromosome Structure: DNA Packing and Chromatin Organization

Study Guide - Practice Questions

Study Guide - Flashcards