No verified paper has been uploaded for CSS Environmental Science Set-10 yet.
The MCQs below are drawn from the Environmental Science subject category.
Showing 31–40
of 2378 MCQs
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31
What is the primary cause of bacillary dysentery and diarrhea in human populations?
Bacillary dysentery and diarrhea are primarily transmitted through the ingestion of contaminated food and water. While specific pathogens like bacteria (e.g., Shigella) or amoebas are the biological agents responsible for the infection, the environmental pathway for the spread of these diseases is the consumption of water or food that has been contaminated with fecal matter.
32
What are the typical physical characteristics of untreated domestic wastewater?
Domestic wastewater is generally characterized by a greyish appearance and a distinct musty or septic odor due to the decomposition of organic matter. Note: The provided answer key suggests 'Blue color, odourless', which contradicts standard environmental science observations; this may be an error in the source material.
33
Which of the following are recognized classifications of water pollution?
Water pollution is categorized by its source and reach. Point-source pollution refers to contaminants entering water from a single, identifiable location like a pipe. Trans-boundary pollution refers to pollution that originates in one jurisdiction but affects water bodies in another, crossing political or geographic borders.
34
Which aquatic organisms are most susceptible to having their gills obstructed by the accumulation of thick sludge?
Fishes rely on gills for gas exchange, extracting dissolved oxygen from water. The presence of thick sludge or suspended solids in polluted water can physically clog the gill filaments, hindering respiration and leading to suffocation or significant physiological stress for the fish.
35
What are the primary sources of nitrogen and phosphate runoff into water bodies?
Nitrogen and phosphorus enter aquatic ecosystems primarily through agricultural runoff, untreated sewage, and industrial waste materials. These nutrients lead to eutrophication, which can cause harmful algal blooms and deplete oxygen levels in the water, negatively impacting aquatic life.
36
How can aquatic weeds be effectively repurposed or processed?
Aquatic weeds, such as water hyacinth, are rich in organic matter and nutrients. They are frequently harvested and processed through composting or anaerobic digestion to create nutrient-rich organic fertilizers, which helps in managing invasive species while improving soil health in agricultural applications.
37
Besides nitrogen, phosphates, and organic pollutants, what other substances are commonly found in wastewater?
Wastewater is a complex mixture containing various contaminants. In addition to organic matter and nutrients like nitrogen and phosphorus, it frequently contains industrial chemicals, heavy metals, and petroleum derivatives, which originate from urban runoff, industrial discharge, and improper disposal of oils and fuels into sewage systems.
38
What term describes the presence of harmful impurities within a water body?
Water pollution occurs when foreign substances, such as chemicals, pathogens, or industrial waste, contaminate water bodies like lakes, rivers, or oceans. This degradation of water quality negatively impacts aquatic ecosystems and human health, rendering the water unsafe for consumption or ecological use.
39
Pathogens are known to cause typhoid and which other waterborne disease?
Typhoid and cholera are both classic examples of waterborne diseases caused by pathogenic microorganisms. Typhoid is caused by Salmonella Typhi, while cholera is caused by Vibrio cholerae. Both diseases are typically transmitted through the ingestion of water or food contaminated with fecal matter containing these bacteria.
40
How does an increased rate of aeration affect the self-purification capacity of a water body?
Aeration increases the dissolved oxygen levels in water. Higher oxygen concentrations facilitate the aerobic decomposition of organic pollutants by microorganisms. Consequently, a greater rate of aeration significantly accelerates the natural self-purification process of a water body, allowing it to recover more quickly from organic contamination.
