(1) they keep toxic substances out of the cell;
(2) they contain receptors and channels that allow specific molecules, such as ions, nutrients, wastes, and metabolic products, that mediate cellular and extracellular activities to pass between organelles and between the cell and the outside environment;
(3) they separate vital but incompatible metabolic processes conducted within organelles.
The answer is operon. These set of genes are transcribed together because they share a single promoter and operator. Therefore they are transcribed into one mRNA and translated together. These genes are, therefore, expressed together at all times. Examples are the tryptophan and lac operons of Escherichia coli
Eutrophication results in the death of trout and other fish as a result of asphyxiation from the lack of oxygen. Eutrophication involves the enrichment of water by nutrients salts such as phosphates, nitrates among others, that causes structural changes of the aquatic ecosystem such as; increased production of algae and aquatic plants, depletion of fish species, deterioration of water quality and other effects that impact negatively the aquatic ecosystem.
Secretary of defense is ahead but not a soldier in rank
In ranking its the general (which is the highest rank in the army)
