PLEASE HURRY. Explain Industrial Ecology and its relation to chemical cycling and the Principle of Sustainability.

19. scientists use meteorites that hit earth to provide evidence of the composition of earth's interior because they hypothesize that

When does the circulatory system work with the respiratory system? a. during blood cell formation b. during cellular respiration c. during intestinal digestion d. during a viral infection

Pls me i need this ! each cell has genes activated depending on it's job and what kind of cell it is. it is the presence of that causes the repressor protein to fall off and unblock the gene on the lac operon. if a gene is turned on then it is being an additional circular chromosome found in some bacteria that is used in genetic engineering.