The dependant variable would be the salmon, because they depend on the water and pollution levels to give a result.
This might help,the presence of hydrochloric acid creates an acidic environment within the stomach that is needed to convert pepsinogen to pepsin. Mucus that is produced by the epithelial cells of the stomach help protect the lining of the stomach from the corrosive hydrochloric acid and pepsin.
Hitherei thinkthe answeris1
In animals, a gene is inserted into an embryo, modifying the genome to manufacture the product of this new gene. In plants, a gene is injected into a single cell that is grown from a seed into a plant. This plant expresses the new gene in all its cells. The difference between GM and selective breeding.
