Question

In the equation GPP – R = NPP, R represents:

• A. Respiration losses
• B. Retardation factor
• C. Environmental factor
• D. Radiant energy

Answer 1

The correct option is A

Respiration losses

The correct option is A.

Explanation of the correct option:

1. Here, GPP stands for Gross Primary Productivity, NPP for Net Primary Productivity and R for Respiration loss.
2. Net primary productivity is defined as the energy fixed by autotrophs (in the form of carbon) after subtracting the carbon lost in respiration. NPP = GPP – Aerobic Respiration
3. The NPP refers to the overall efficiency of the plants in the ecosystem.
4. The GPP refers to the rate of energy stored by photosynthesis in plants.
5. The R refers to the rate of energy loss.

Explanation of the incorrect options:

Option B:

1. The R_f (retardation factor) value is the ratio of the distance travelled by the solute to the distance travelled by the solvent in a solution.
2. The word comes from chromatography when it was discovered that a given component will always travel the same distance in a given solvent under the same conditions.
3. It is possible to determine the characteristic rate of movement of each substance on the chromatography paper as the moving phase moves at a certain temperature and for a specific solvent.
4. This is represented by the R_f value, which stands for relative front or retardation factor.

Option C:

1. An environmental factor is any factor, abiotic or biotic, that influences and affects living organisms.
2. Environmental factors include temperature, food, pollutants, population density, sound, light, and parasites.
3. Some environmental factors cause adverse affects in our health like skin diseases, loss of oxygen, respiratory problems etc.

Option D:

1. Radiant energy is the physical energy resulting from electromagnetic radiation, usually observed as it radiates from a source into the surrounding environment.
2. Radiant energy sources include the entire electromagnetic radiation spectrum, including gamma rays, x-rays, radio frequencies, microwaves, light and heat.
3. Radiant energy described in terms of either discrete packets of energy, called photons, or continuous electromagnetic waves.

Final answer: In the equation GPP – R = NPP, R represents respiration loss.