1. What does destruction refer?

168. Sources of particulates are divided into those arising from a single, well-
defined emission source, which is called _________.
A) Microbiological contaminants
B) Point-source pollution
C) Physical contaminants
D) Chemical contaminants
E) Non-point source pollution
169. Choose the correct types of aquatic ecosystem:
A) Marine and tundra
B) Tundra and freshwater
C) Grassland and desert
D) Forest and marine
E) Freshwater and marine
170
. Choose the correct determination for “biological pollution” as a stress factor in 
ecosystem modelling
A) They are associated with interactions occurring among organisms, such as competition, 
herbivory, predation, parasitism, and disease. For example, individuals of the same or 
different species may compete for essential resources that are limited in supply. Herbivory, 
predation, parasitism, and disease are trophic interactions, in which one species exploits 
another
B) It occurs when people release organisms beyond their natural range. This might involve 
the introduction of alien species that invade and alter natural habitats, or it may be the 
release of pathogens into the environment through discharges of raw sewage
C) It is associated with insufficient or excessive regimes of temperature, moisture, solar 
radiation, wind, or combinations of these

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D) It is caused by the release of heat (thermal energy) into the environment, which results 
in ecological stress because species vary in their tolerance of temperature extremes. 
Thermal stress may occur at natural springs and submarine vents where geologically 
heated water is emitted. It is also associated with discharges of hot water from power 
plants
E) It is caused by excessive exposure to ionizing energy. The radiation may be emitted by 
nuclear waste or explosions, or it can be diagnostic X-rays or solar ultraviolet energy