1. What does destruction refer?

90. A hawk soaring above a field hunting for a field mouse is an example of which 
relationship?
A) Competition
B) Predation
C) Symbiosis
D) Proto cooperation
E) Parasitism
91. What is the distinguishing feature of soil pollution?
A) pollution is not related to air pollution
B) self-cleaning is slow
C) the soil is not self-cleaning
D) soil contaminants are not hazardous
E) pollution is not related to water pollution
92. The total amount of living tis
sue within a given trophic level is called … .

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A) Organic mass
B) Energy mass
C) Tropic mass
D) Nutrient mass
E) Bio mass
93. What is the main cause for the smog?
A) the presence of the wind
B) lack of wind
C) a decrease of O3
D) the transparency of air
E) temperature inversion
94
. Choose the correct definition for functional unit of ecosystem “energy flow”.
A) It is the process of breakdown of dead organic material. The top-soil is the major site for 
decomposition
B) In an ecosystem nutrients are consumed and recycled back in various forms for the 
utilisation by various organisms
C) It is the sequential process through which energy flows from one trophic level to 
another. The energy captured from the sun flows from producers to consumers and then to 
decomposers and finally back to the environment
D) The increasing concentration of a compound in the tissues of organisms as the 
compound passes along a food chain, resulting from the accumulation of the compound at 
each trophic level prior to its consumption by organisms at the next trophic level, as seen 
with DDT
E) It refers to the rate of biomass production
95. Major components of ecosystems are:
A) Functional
B) Structural
C) Abiotic factors
D) Structural and functional
E) Climatic factors