Which of these statements about nucleosomes are correct?

a. The histones H2A, H2B, H3, and H4 make up the nucleosome octamer that binds DNA.
b. Most histones are small (less than 150 amino acid residues), basic proteins rich in Lys and Arg.
c. DNA binding to histones has the same effect as positive supercoiling.
d. Degradation of linker DNA yields DNA fragments of about 200 bp.
e. Partial enzymatic digestion of chromatin results in DNA fragments of about 103 bp.

12) several teeth were found in an area of flat land covered with trees and plants. the teeth were examined by a paleontologist, and it was determined that the teeth came from a shark. they found many other shark teeth in this area. however, the people who discovered the teeth were puzzled, because there was no source of water near where the fossils were found. what is the paleontologist's best explanation for why the teeth were found in this area? a) sharks used to live on flat land. b) this area was once covered with salt water. c) this area was once covered with freshwater. d) someone buried the shark teeth deep in the ground.