Concept explainers
A nucleosome consists of (a) DNA and scaffolding proteins (b) scaffolding proteins and histones (c) DNA and histones (d) DNA, histones, and scaffolding proteins (e) histones only
Introduction: A chromosome is a thread-like structure made up of DNA. It is tightly packed in the nucleus of a cell. Humans normally have 23 pairs of chromosomes.
Answer to Problem 1TYU
Correct answer: A nucleosome consists of DNA and histones. Hence, the correct answer is option (c).
Explanation of Solution
Reason for the correct answer:
The nucleosome is the basic unit of chromatin structures. The basic unit of each nucleosome contains a bead-like structure that has 146 DNA base pairs wrapped around the disc-shaped core of eight histone molecules. The nucleosomes prevent the DNA from becoming tangled. Histones play an important part in the regulation of gene expression.
Option (c) is given as “DNA and histones”.
The nucleosome consists of DNA and histones.
Hence, the correct answer is option (c).
Reasons for the incorrect answers:
Option (a) is given as “DNA and scaffolding proteins”.
Nucleosomes consist of DNA, but scaffolding proteins are not present in nucleosomes.
Hence, option (a) is incorrect.
Option (b) is given as “scaffolding proteins and histones”.
Scaffolding proteins are modular proteins that play a crucial role in cell-signaling pathways. Scaffolding proteins are not present in nucleosomes. Histones proteins are present in nucleosomes.
Hence, option (b) is incorrect.
Option (d) is given as, “DNA, histones, and scaffolding proteins”.
Nucleosomes consist of DNA and histones, but scaffolding proteins are not present. Hence, option (d) is incorrect.
Option (e) is given as, “histones only”.
Not only histones, but DNA is also present in the nucleosomes.
Hence, option (e) is incorrect.
Hence, options (a), (b), (d), and (e) are incorrect.
The nucleosome is the basic unit of chromatin structures that consist of DNA and histones.
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Chapter 10 Solutions
Biology (MindTap Course List)
- what is the difference between chromatid and chromatin?arrow_forwardThe DNA in a cell associates with proteins to form chromatin. What is a nucleosome?arrow_forwardWhat are the components of a single nucleosome?a. About 146 bp of DNA and four histone proteinsb. About 146 bp of DNA and eight histone proteinsc. About 200 bp of DNA and four histone proteinsd. About 200 bp of DNA and eight histone proteinsarrow_forward
- If a human nucleus is 10 mm in diameter, and it must hold as much as 2 m of DNA, which is complexed into nucleosomes that during full extension are 11 nm in diameter, what percentage of the volume of the nucleus is occupied by the genetic material?arrow_forwardWhich of the following make up a core nucleosome structure? A) about 147 bp of DNA D) A tetramer of histone proteins C) H1 histone E) Answers A and B are correct B) an octamer of histone proteinsarrow_forwardWhat role do histones play in nucleosomes?arrow_forward
- a) How come cells in a multicellular organism look different and have different functions? b) How could this be linked to the chromatin structure?arrow_forwardWhat are the components of a single nucleosome?a. About 146 bp of DNA and four core histone proteinsb. About 146 bp of DNA and eight core histone proteinsc. About 200 bp of DNA and four core histone proteinsd. About 200 bp of DNA and eight core histone proteinsarrow_forwardIn all cells, microtubules nucleate from the centrosome and then become stabilized or collapse. What feature of microtubules contributes to this phenomenon?arrow_forward
- What is nucleosome and chromatin?arrow_forwardWhat is the basic difference between DNA, gene, chromosome, & chromatin? If chromosome does not condensed with histone protein, what problems may occur?arrow_forwardIn nucleosome, the DNA is wrapped around a. histones b. ribosomes c. polymerase molecule d. a thymine dimerarrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning