7. DNA and Chromosome Structure

Eukaryotic Chromosome Structure

Multiple Choice
Which of the following terms is used to describe 'open chromatin' which is loosely packaged DNA?
Multiple Choice
Histone proteins are responsible for what?
Multiple Choice
Which of the following is the correct order of chromosomal packaging levels?
Multiple Choice
What is the name of the enzyme that removes supercoils in DNA?
Open Question
Give descriptions for the following terms: chromosome territory
Open Question
Give descriptions for the following terms: nucleosome
Open Question
Give descriptions for the following terms: heterochromatin
Open Question
Give descriptions for the following terms: euchromatin
Open Question
Give descriptions for the following terms: G bands
Open Question
Give descriptions for the following terms: scaffold proteins
Open Question
Give descriptions for the following terms: nucleosome core particle
Open Question
In this chapter, we focused on how DNA is organized at the chromosomal level. Along the way, we found many opportunities to consider the methods and reasoning by which much of this information was acquired. From the explanations given in the chapter, what answers would you propose to the following fundamental questions:How did we learn that eukaryotic chromatin exists in the form of repeating nucleosomes, each consisting of about 200 base pairs and an octamer of histones?
Open Question
The human genome contains 2.9×10⁹ base pairs. Approximately how many nucleosomes are required to organize the 10-nm–fiber structure of the human genome? Show the calculation you use to determine the answer.
Open Question
In eukaryotic DNA,

how does the role of H1 differ from the role of H3 in chromatin formation?
Open Question
In eukaryotic DNA,

along a 6000-bp segment of DNA, approximately how many molecules of each kind of histone protein do you expect to find? Explain your answer.