#Question id: 2906
#Unit 2. Cellular Organization
A closer look at the interactions between the histones and the nucleosomal DNA reveals the structural basis for the binding and bending of the DNA within the nucleosome. Fourteen distinct sites of contact are observed, one for each time the minor groove of the DNA faces the histone octamer. State whether the following set of statements is true/false regarding this association?
I. The majority of these associations are between the proteins and the oxygen atoms in the phosphodiester backbone near the minor groove of the DNA.
II. The association of DNA with the nucleosome is mediated by a large number (about 40) of hydrogen bonds between the histones and the DNA.
III. Maximum numbers of hydrogen bonds are made between the protein side chains and the bases, and all of these are made in the minor groove of the DNA.
IV. The highly basic nature of the histones further facilitates DNA bending by masking the negative charge of the phosphates that ordinarily resists DNA bending.
V. The positively charged nature of the histones facilitates the close juxtaposition of the two adjacent DNA helices necessary to wrap the DNA more than once around the histone octamer.
#Question id: 16317
#Unit 7. System Physiology – Animal
#Question id: 6972
#Unit 5. Developmental Biology
Sodium ions influx and passive water movement result in fluid-filled blastocoel in __________embryos.
#Question id: 12138
#Unit 10. Ecological Principles
#Question id: 3667
#Unit 3. Fundamental Processes
In an ______________ plasmid, replication occurs in two stages. In the first stage, the double stranded circular plasmid DNA replicates to form another double-stranded circular DNA and a single-stranded circular DNA, In the second stage, the complementary strand is synthesized on the single-stranded DNA to make another double-stranded DNA.