Answer:
Productivity is refers to the rate of generation of biomass in an ecosystem. The difference between net and gross productivity is that gross productivity is is the overall rate of energy capture while net productivity is is lower, adjusted for energy used by organisms in respiration/metabolism.
Explanation:
An agonist exhibit a positive biological effect similar to the receptor it stimulates. For instance, beta agonists (i.e. Salbutamol) stimulate the beta receptors in the bronchial system therefore leading to bronchodialtion. A competitive antagonist negates the function of the specific receptor by binding to the receptor binding site before the biological ligand. A non-competitive agonist negates the function of the specific receptor by binding to an allosteric site leading to a conformational change of the receptor site.
..... A. The same
all the others don't make sense.