The hypothalamus in the brain contributes to the body's maintenance of a steady internal physiological state, called homeostasis.
The first one is commensalism. The second one is mutualism. The last one is parasitism.
Organism, population, community, ecosystem, biosphere
<span>It means that they only act on certain types of substrates. Each enzyme is </span><span>specific in that they do not work for all molecules.</span>