In an ecosystem, if the net primary productivity (NPP) of the first trophic level is , what would be the GPP (Gross Primary Productivity) of the third trophic level of the same ecosystem? [2024]
In the equation
| GPP - R = NPP |
GPP is Gross Primary Productivity
NPP is Net Primary Productivity
R here is ______. [2023]
respiratory loss
reproductive allocation
photosynthetically active radiation
respiratory quotient
(1)
Gross primary productivity (GPP) of an ecosystem is the rate of production of organic matter during photosynthesis. A considerable amount of GPP is utilised by autotrophs in respiration. Gross primary productivity minus respiration losses (R) is the net primary productivity (NPP).
GPP - R = NPP
In the equation, GPP – R = NPP
R represents [2021]
respiration losses
radiant energy
retardation factor
environment factor
(1)
A considerable amount of GPP is utilised by plants in respiration (R). The energy left after respiration and stored as organic matter in the producers per unit time and area is NPP.
NPP = GPP - R
In relation to Gross Primary Productivity and Net Primary Productivity of an ecosystem, which one of the following statements is correct? [2020]
Gross primary productivity is always less than Net primary productivity.
Gross primary productivity is always more than Net primary productivity.
Gross primary productivity and Net primary productivity are one and same.
There is no relationship between Gross primary productivity and Net primary productivity.
(2)
Gross primary productivity (GPP) is the rate of production of organic matter during photosynthesis. A considerable amount of GPP is utilised by plants in respiration. GPP minus respiration losses (R) is the net primary productivity (NPP).
GPP - R = NPP
Therefore, GPP is always more than NPP.
The mass of living material at a trophic level at a particular time is called [2015]
net primary productivity
standing crop
gross primary productivity
standing state
(2)
Standing crop is the total amount of living material in a specified population at a particular time, expressed as biomass (standing biomass) or its equivalent in terms of energy. The standing crop may vary at different times of the year; for example, in a population of deciduous trees between summer and winter.
In an ecosystem the rate of production of organic matter during photosynthesis is termed as [2015]
secondary productivity
net productivity
net primary productivity
gross primary productivity
(4)
The amount of energy accumulation in green plants as biomass or organic matter per unit area over a time period is known as primary productivity. The rate of total capture of energy, or the rate of total production of organic material (biomass), is known as gross primary productivity.
Given below are two statements: [2025]
Statement I : The primary source of energy in an ecosystem is solar energy.
Statement II : The rate of production of organic matter during photosynthesis in an ecosystem is called net primary productivity (NPP).
In the light of the above statements, choose the most appropriate answer from the options given below:
Both statement I and statement II are correct
Both statement I and statement II are incorrect
Statement I is correct but statement II is incorrect
Statement I is incorrect but statement II is correct
(3)
Primary source of energy in the ecosystem is solar energy.
Gross primary productivity of an ecosystem is the rate of production of organic matter during photosynthesis. Hence, statement I is correct but statement II is incorrect.
Which of the following is the unit of productivity of an Ecosystem? [2025]
(4)
The rate of biomass production is called productivity. It is expressed in terms of or to compare the productivity of different ecosystems.
Given below are two statements: [2025]
Statement I: In ecosystem, there is unidirectional flow of energy of sun from producers to consumers.
Statement II: Ecosystems are exempted from 2nd law of thermodynamics.
In the light of the above statements, choose the most appropriate answer from the options given below:
Both statement I and statement II are correct
Both statement I and statement II are incorrect
Statement I is correct but statement II is incorrect
Statement I is incorrect but statement II is correct
(3)
Sun is the only source of energy for all ecosystems on Earth, except for deep sea-hydro-thermal ecosystem.
The energy flow is unidirectional from the sun to producers and then to consumers.
Ecosystems are not exempted from the second law of thermodynamics. They need a constant supply of energy to synthesise the molecules they require to counteract the universal tendency towards increasing disorderliness.
