When DNA Is Compacted by Histones into 10-Nm and 30-Nm

question 96

Multiple Choice

When DNA is compacted by histones into 10-nm and 30-nm fibres, the DNA is unable to interact with proteins required for gene expression. Therefore, to allow for these proteins to act, the chromatin must constantly alter its structure. Which processes contribute to this dynamic activity?

• A)DNA supercoiling at or around H1
• B)methylation and phosphorylation of histone tails
• C)hydrolysis of DNA molecules where they are wrapped around the nucleosome core
• D)accessibility of heterochromatin to phosphorylating enzymes
• E)nucleotide excision and reconstruction

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The systematic allocation of the cost of a tangible asset over its useful life, reflecting the decrease in value due to wear and tear, aging, or obsolescence.

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