In molecules, two types of excited states can exist singlet and triplet  

(a) The singlet state is relatively long‐lived than triplet and have parallel spin

(b) The singlet state is relatively short‐lived than triplet and have antiparallel spin

(c) The triplet state is relatively long‐lived than singlet and have two parallel spin

(d) The triplet state is relatively long‐lived than singlet and have two anti-parallel spin

Which of the following is correct 

#Question id: 11292

#Unit 10. Ecological Principles

In an pond ecosystem the _____ is always greater than the _____ .

(a) number of primary producers . . . number of secondary consumers

(b) biomass of secondary consumers . . . biomass of primary consumer

(c) assimilation efficiency of primary consumers . . . assimilation efficiency of secondary consumers

(d) biomass of primary producers . . . biomass of primary consumers

#Question id: 11293

#Unit 10. Ecological Principles

Measurement of phytoplankton production, take sample of phytoplankton suspended in two bottles in lake. One bottle (D) is dark in colour but second bottle (L) light in colour. After some time productivity measure as follow Where Lo –oxygen concentration in light bottle, Do –oxygen concentration in Dark bottle, Io –oxygen concentration in bottle before incubation    

A)  Lo- Do                     B) Lo- Io  C) Io- Do

#Question id: 11294

#Unit 10. Ecological Principles

A small lake has three trophic level – Phytoplankton(autotroph) , Zooplankton (herbivore ) and planktivorous fish ( primary carnivore) . In to this lake Population of some other primary carnivore introduced to study top down effect . What is expected long term consequence of this  introduction ?

#Question id: 11295

#Unit 10. Ecological Principles

The amount of energy entering a food chain depends on the

#Question id: 11296

#Unit 10. Ecological Principles

Which of the following statements is true?

#Question id: 11297

#Unit 10. Ecological Principles

What is the difference between gross and net primary production?