The addition of acetyl groups makes histones positively charged, and thus their affinity for dna.

Can nonrenewable resources be used sustainably?   a. yes, nonrenewable resources are always beneficial for the environment  b. no, there are only negative effects of using nonrenewable resources  c. no, there's a finite amount of nonrenewable resources  d. yes, as long as use doesn't exceed availability is the correct answer   d. yes, as long as use doesn't exceed availability