Acetylation of histones in the vicinity of a gene causes the gene to be activated because the histones bind less tightly to the DNA than unacetylated histones. silenced because the histones bind less tightly to the DNA than unacetylated histones. activated because the histones bind more tightly to the DNA than unacetylated histones. silenced because the histones bind more tightly to the DNA than unacetylated histones.

the generally accepted parts of modern cell theory include: all known living things are made up of one or more cells. all living cells arise from pre-existing cells by division. the cell is the fundamental unit of structure and function in all living organisms.

only about ten percent of the energy at one trophic level is passed on to organisms at the next trophic level. the remainder of the energy is used in life processes or lost as heat.