Suppose an explorer discovered a unique new species of plant and collected a sample for analysis by a geneticist. The geneticist
then isolated chromatin from the plant sample and examined the chromatin using electron microscopy. The chromatin observed was organized in a way that is similar to beads on a string A small amount of nuclease was then added, which was observed to cleave the string into individual beads that each contained 280 bp of DNA. Histone H1 H2A H2B H3 H4 H7 (new histone)
Percentage 12.5% 25% 25% 0% 26%
After thorough digestion with more nuclease, only a 120 bp fragment of DNA remained attached to a core of histone eins. Analysis of the histone core revealed the data dicated in the table to the right.
Using the data provided, determine the conclusions that the geneticist could make about the likely structure of the nucleosome in the chromatin of this new plant species
A. The nucleosome core contains a heterodimer of the histones H7 and H1
B. The nucleosome core contains two each of histones H2A, H2B, and H4
C. The nucleosome core contains a homodimer of the histones H2A, H2B, and H4
D. The nucleosome core contains one each of histones H1 and H7
E. The nucleosome core histone H7 replaces the standard histone H3
