There are two types of photoreceptors:

Rods 

Cones

TLS Online TPP Program

#Id: 5943

#Unit 10. Ecological Principles

Components of primary production

a. Gross primary production - Total organic matter production including reparatory loss during measurement of period.

b. Net primary production - Amount of matter accumulated by plant per unit area given time. 

 Gross – net = respiration 

TLS Online TPP Program

#Id: 5944

#Unit 10. Ecological Principles

TLS Online TPP Program

#Id: 5945

#Unit 10. Ecological Principles

Efficiency of Gross primary production Trophic-level transfer efficiency appears to average around 10%, though there is much variation. In some marine food chains, for example, it can exceed 30%.

TLS Online TPP Program

#Id: 5946

#Unit 10. Ecological Principles

Deserts are not very efficient at converting huge amounts of incident energy from sunlight into plant biomass.  Most ecosystems based on phytoplankton have very low efficiencies, usually less than 0.5%.

Photosynthetic efficiency of an ecosystem as a whole varies between 1% and 2%.

TLS Online TPP Program

#Id: 5947

#Unit 10. Ecological Principles

TLS Online TPP Program

#Id: 5948

#Unit 10. Ecological Principles

Efficiency of Energy transfer The efficiency of energy transfer is influenced by the established laws of thermodynamics.

Efficiency of consumers as energy transformers is trophic-level transfer efficiency