Ecosystem short answer questions

31. What are the three main biotic components of an ecosystem?
Producers, consumers and decomposers are the three main biotic components of an ecosystem.
32. How do decomposers obtain food?
Decomposers release their enzymes into dead and decaying plant and animal remains and absorb the simple inorganic substances.
33. What is productivity?
Productivity, is the rate of synthesis of energy containing organic matter by any ecosystem per unit area in unit time. •
34. What are the key functional aspects of ecosystems? Productivity and energy flow, nutrient cycling, development and stabilization are the key functional aspects of ecosystems.
35. What is detritus?
Dead plant parts and animal remains are called detritus. Above ground detritus (litter fall) constitutes dead remains of plants and animals, but root detritus (below ground detritus) constitute dead roots.
36. What is nutrient immobilization?
Soil nutrients get tied up with biomass of microbes and is not available for other organisms. Such incorporation of nutrients in living microbes is called nutrient immobilisation.
37. How is photosynthetic efficiency calculated?
Gross primary productivity x100
Photosynttietic efficiency = Incident total solar radiation
38. What is humus?
The dark- coloured amorphous substance formed as a result of humification and mineralisation, which is rich in nutrients is called humus.
39. What is agroecology?
The study of the relationship between crops and environment is termed agroecology.
40. What is PAR?
PAR is photosynthetically active radiation. The visible light which carries 50% of the energy of total incident solar radiation constitutes PAR.
41. How is phosphorus used by living organisms? Phosphorus is used to form energy currency, ATP and nucleotides which join to form nucleic acid.
42. What are ecological pyramids?
A graphic represeniation of energy transfer in a food chain through a pyramidal figure is called ecological pyramid.