<span>The macrophage is the cell responsible for detecting, engulfing and destroying pathogens and apoptotic cells. These cells process and present antigens (foreign materials) to immunocompetent cells and thus they are the key mediators in the development of all immune reactions.</span>
The hypothalamus sends signals to the pituary glands. The hypothalamus releases dopamine, so I think dopamine is a good answer?
The Answer is A but im only about 5% sure about my answer
Metabolism, respiration and digestion are all complex chemical processes involving many steps, happening in 3 dimensional space within cells. Metabolism is the breaking of bonds within food molecules (like sugar) to harness energy for cellular work; respiration involves moving oxygen and carbon dioxide gases between cells to facilitate cellular metabolism and digestion involves breaking down food macro structures into smaller units suitable for metabolism.
So the answer is D - each of the three process involve multiple chemical reactions.