Question

The rate of biomass production and the rate of production of organic matter during photosynthesis are called _______respectively.
(a)Total productivity and primary production.
(b)Gross primary productivity and gross secondary productivity
(c)Net primary productivity and secondary productivity
(d)Productivity, gross primary productivity, net productivity, and gross secondary productivity

Answer 1

Hint: Productivity is the rate at which energy is added to the bodies of a group of organisms, such as primary producers, in the form of biomass and gross productivity can be defined as the overall rate of energy capture. The net productivity reflects the amount of energy stored as biomass. The energy used by the organisms in respiration/metabolism is adjusted by the gross productivity.

Complete answer:
Plants, algae, and photosynthetic bacteria act as producers. Producers are autotrophs, or "self-feeding" organisms, that make their organic molecules from carbon dioxide. The energy that is generated by them is stored in the chemical bonds of the molecules, which are used as fuel and building material by the plant. The term productivity in ecology can be defined as the rate of generation of biomass in an ecosystem. It is usually expressed in units of mass per volume (unit surface) per unit of time, such as grams per square meter per day. The unit of mass can relate to dry matter or the mass of generated carbon. . Biomass is simply the amount of matter that's stored in the bodies of a group of organisms. The gross primary productivity or GPP can be defined as during photosynthesis the rate at which solar energy is captured in sugar molecules (energy captured per unit area per unit time). Again we can understand the net primary productivity or NPP as gross primary productivity minus the rate of energy loss to metabolism and maintenance. Or it can also be said as the rate at which energy is stored as biomass by plants or other primary producers and made available to the consumers in the ecosystem is called NPP.

Additional Information: 1)The primary productivity in aquatic ecosystems is driven by the availability of nutrients and light and, to a lesser extent, by temperature and other factors. It is important because, in most ecosystems, it is the process that forms the foundation of food webs.
2) In swamps and marshes and tropical rainforests of the terrestrial environment has the highest net primary productivity whereas the lowest can be found in deserts.
3) Solar radiation and temperature, moisture(leaf water potential, soil moisture, fluctuation of precipitation, and transpiration), mineral nutrition, the impact of human populations(populations of different sorts, ionizing radiations, such as atomic explosions) affects the productivity of an ecosystem.
So, the correct answer is, ‘Total productivity and primary productivity.’

Note: When organic molecules from an organism's body are eaten by another organism, the energy can pass from one trophic level to the next. However, this energy transferred between trophic levels is not usually very efficient. Only about 10% of the total energy stored on average as biomass in one trophic level (e.g., primary producers) gets stored as biomass in the next trophic level (e.g., primary consumers). If we put this transfer of energy in another way, net productivity usually drops by a factor of ten from one trophic level to the next.