Somatic cells contain two alleles for every gene, with one allele provided by each parent of an organism. Often, it is impossible to determine which two alleles of a gene are present within an organism's chromosomes based solely on the outward appearance of that organism.
Net Primary Productivity (NPP) is the amount of carbon uptake after subtracting Plant Respiration (RES) from Gross Primary Productivity (GPP). GPP is the total rate at which the ecosystem capture and store carbon as plant biomass, for a given length of time. NPP = GPP â RES.
Marginal physical product. The physical output that is due to the addition of one more unit of a variable factor of production; the change in total product occurring when a variable input is increased and all other inputs are held constant; also called marginal product.