In the prokaryote b. subtilis, the rna polymerase holoenzyme binds to a set of promoters when nutrients are readily available, and to a different set of promoters under conditions of nutrient deprivation. the ability of the holoenzyme to bind different promoters under these conditions involves a switch of one subunit. remembering the functions of the rna pol holoenzyme subunits discussed in class, which subunit is most likely to enable this change in promoter binding?

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.

sand 60

clay 10

silt 30

sandy loam should be dominated by the sand. as the amount of sand increased, the amount of slit needed to anchor the plants' roots to the sand will also be increased. even though the amount is very little, 10% part of clay is still necessary for proper oxidation.