DNA and Chromosome
1) Which of the following statements accurately describes one characteristic of histones?
A) Each nucleosome consists of two molecules of histone H1.
B) Histone H1 is not present in the nucleosome bead; instead, it draws the nucleosomes together.
C) The carboxyl end of each histone extends outward from the nucleosome and is called a "histone tail."
D) Histones are found in mammals, but not in other animals or in plants or fungi.
2) Which of the following molecular characteristics cause histones to bind tightly to DNA?
A) Histones are positively charged, and DNA is negatively charged.
B) Histones are negatively charged, and DNA is positively charged.
C) Both histones and DNA are strongly hydrophobic.
D) Histones are covalently linked to the DNA.
3) Which of the following lists represents the order of increasingly higher levels of organization of chromatin?
A) nucleosome, 30-nm chromatin fiber, looped domain
B) looped domain, 30-nm chromatin fiber, nucleosome
C) nucleosome, looped domain, 30-nm chromatin fiber
D) 30-nm chromatin fiber, nucleosome, looped domain
4) Which of the following statements correctly describes the structure of chromatin?
A) Heterochromatin is composed of DNA, whereas euchromatin is made of DNA and RNA.
B) Both heterochromatin and euchromatin are found in the cytoplasm.
C) Heterochromatin is highly condensed, whereas euchromatin is less compact.
D) Euchromatin is not transcribed, whereas heterochromatin is transcribed.
5) Which of the following structural characteristics is most critical for the association between histones and DNA?
A) Histones are small proteins.
B) Histones are highly conserved (that is, histones are very similar in every eukaryote).
C) There are at least five different histone proteins in every eukaryote.
D) Histones are positively charged.
6) If a cell were unable to produce histone proteins, which of the following results would be a likely effect on the cell?
A) There would be an increase in the amount of DNA produced during replication.
B) The cell's DNA could not be packed into its nucleus.
C) Spindle fibers would not form during prophase.
D) Amplification of other genes would compensate for the lack of histones.
7) Which of the following statements accurately describes the structure of a eukaryotic chromosome?
A) It is composed of a single strand of DNA.