Please refer to Assignments Class 12 Biology Ecosystem Chapter 14 with solved questions and answers. We have provided Class 12 Biology Assignments for all chapters on our website. These problems and solutions for Chapter 14 Ecosystem Class 12 Biology have been prepared as per the latest syllabus and books issued for the current academic year. Learn these solved important questions to get more marks in your class tests and examinations.
Ecosystem Assignments Class 12 Biology
Question. The rate of biomass production is called productivity.
It may be primary or secondary productivity. Primary productivity does not depends on
(a) Plants species inhabitating a particular area
(b) Predation
(c) Environmental factors
(d) Photosynthetic capacity
Answer
B
Question. Which among the following is not considered as an ecological service?
(a) Generation of fertile soil
(b) Wild life habitat formation
(c) Products of antibiotics
(d) Crop pollination
Answer
C
Question. Which among the following factors are most important climatic factors that regulate decomposition through their effects on the activities of soil microbes
(a) Temp & soil moisture
(b) Temp and pH of soil
(c) Temp and oxygen
(d) pH of soil and oxygen
Answer
A
Question. Decomposition is one of the important functional aspect of ecosystem. Which of the following statement is not correct for decomposition ?
(a) Warm and moist environment favours decomposition
(b) Nitrogen and sugar component favours decomposition
(c) Low temperature and anaerobiosis favours decomposition
(d) Decomposition is largely an oxygen requiring process
Answer
C
Question. Robert Constanza and his colleagues have put price tags on natures life support services with refrence to this which of the following is not true?
(a) Fundamental ecosystem services = $ 33 trillions
(b) Soil formation = $ 16.5 trillions
(c) Nutrient cycling = less than $ 3.3 trillions
(d) Climate regulation = $ 5 trillions
Answer
D
Question. The annual net primary productivity of the whole biosphere is approximately
(a) 170 billion tons
(b) 50 billion tons
(c) 55 billion tons
(d) 710 billion tons
Answer
A
Question. By digestion and pulverisation detritus get fragmented. This fragmentation step of decomposition helps in
(a) Increasing porocity of detritus
(b) Increasing surface area of detritus
(c) Increasing rate of sedimentation
(d) All of these
Answer
B
Question. Which of the following regulate the rate of release of nutrients into atmosphere
(a) Soil
(b) Moisture
(c) pH and Temperature
(d) All the above
Answer
D
Question. In net primary productivity of whole biosphere what is the contribution of oceans in billion ton ?
(a) 50
(b) 70
(c) 42
(d) 55
Answer
D
Question. What percentage of carbon constitute the dry weight of organisms
(a) 49 %
(b) 71 %
(c) 30 %
(d) 20 %
Answer
A
Question. Leaching is one of the important step of decomposition. During leaching, which of the following nutrient go down into the soil horizon ?
(a) Water soluble inorganic substance
(b) Water insoluble inorganic substances
(c) Water soluble organic substances
(d) Both water soluble organic substances and inorganic substances
Answer
D
Question. Which of the following chemical will not reduce the rate of decomposition of detritus
(a) Lignin
(b) Chitin
(c) Cutin
(d) Sugars
Answer
D
Question. How much amount of incident solar radiation and PAR is capture as GPP respectively :-
(a) 1-5% and 2-10%
(b) 2-10% and 1-5%
(c) 1-4% and 2-8%
(d) 0.4-4% and 0.8-8%
Answer
A
