The H3.H4 tetramers and H2A.H2B dimers each interact with a particular region of the DNA within the nucleosome. Which of the following statement is CORRECT regarding the characteristic binding of histones with the DNA?

I. Of the 147 bp of DNA included in the structure, the histone-fold regions of the H2A.H2B dimer interact with the central 60 bp.

II. Histone H3.H4 tetramers occupy a key position in the nucleosome by binding the middle and both ends of the DNA.

III. The amino-terminal region of H4 most proximal to the histone-fold region forms a fourth alpha helix that interacts with the final 13 bp at each end of the bound DNA.

IV. The H3.H4 tetramer associate with approximately 30 bp of DNA on either side of the central 60 bp of DNA bound by H2A.H2B dimer.

V. The two H2A.H2B dimers form the bottom part of the histone octamer located across the disc from the DNA ends.

#Question id: 5587

#Unit 5. Developmental Biology

Which gene on the Y chromosome transforms the bipotential gonad into a testis in mammals?

#Question id: 15986

#Unit 12. Applied Biology

#Question id: 5034

#Unit 11. Evolution and Behavior

Which of these statements about human evolution is correct?

#Question id: 542

#Unit 1. Molecules and their Interaction Relevant to Biology

Hamsters love to run on exercise wheels. Prolonged running at a high rate of speed requires ATP. Could a hamster with a defective gene for the enzyme lactate dehydrogenase meet the extra ATP demand for prolonged, fast wheel-running by maintaining a high rate of glycolysis? Why or why not?

#Question id: 3555

#Unit 8. Inheritance Biology

In watermelons, bitter fruit (B) is dominant over sweet fruit (b), and yellow spots (S) are dominant over no spots (s). The genes for these two characteristics assort independently. A homozygous plant that has bitter fruit and yellow spots is crossed with a homozygous plant that has sweet fruit and no spots. If an F1 plant is cross with the heterozygous for bitter and no spots, what phenotypes ratio are expected in the offspring?