A DNA double helix that is exposed on one side to DNase I or II (enzymes that nick one strand of DNA rather than cleave both) would be expected to generate single strands that average 10.5 bases in length, the length of a helical turn of DNA
However, DNase treatment of core nucleosomal DNA produces fragments that average 10.0 bases at the ends and 10.7 bases in the middle. What does this suggest?
What will be an ideal response?
Ans: This result suggests that the helical periodicity of core nucleosomal DNA is altered by being associated with the nucleosome. This alteration varies with the exact position of the core DNA.
You might also like to view...
The ancestor to all plants is believed to be
a. a green alga. b. a red alga. c. a brown alga, like kelp. d. a diatom. e. a sea grass.
A mechanism shared by both extracellular and intracellular digestion is
A. a slow speed of digestion. B. the ability to phagocytose food particles. C. the ability to consume both large and small food items. D. the presence of a digestive cavity.
Which of the following technologies seeks to manipulate components of the environment to bring about positive change?
A. ocean acidification B. genetic engineering C. geoengineering D. eutrophication
Which of the following is a reason for the occurrence of a lag phase in a bacterial growth curve?
A. The organisms may have been injured and require time to recover. B. The medium may be different from the previous growth medium so that the cells must synthesize new enzymes to use different nutrients. C. The cells may be old and depleted of ATP, essential cofactors, and ribosomes that must be synthesized before growth can begin. D. All of these are potential reasons.