Studies of nucleosomes have shown that histones (except H1) exist in each nucleosome as two kinds of tetramers: one of 2 H2A molecules and 2 H2B molecules, and the other as 2 H3 and 2 H4 molecules. Which of the following is supported by this data?
A) DNA can wind itself around either of the two kinds of tetramers.
B) The two types of tetramers associate to form an octamer.
C) DNA has to associate with individual histones before they form tetramers.
D) Only H2A can form associations with DNA molecules.
E) The structure of H3 and H4 molecules is not basic like that of the other histones.
Chromosomal DNA is wrapped around histones
Shown eating. Cougars are ambush predators, feeding mostly on deer and other mammals.
One of the reasons I went to Cambodia was to interview a feral child—the boy shown here—who ...
Desmosomes and gap junctions, as shown in heart muscle.
Cranial nerves and their target regions. (Sensory nerves are shown in blue; motor nerves, in red.)
A current-carrying wire is placed in a uniform magnetic field, as shown below.