OBJECTIVE LIFE SCIENCE
ECOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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nitrogen compounds are recycled
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the concentration of oxygen drops below the necessary level
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an algal bloom occurs
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algae begin to die and decomposers take over
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Detailed explanation-1: -An overabundance of nutrients-primarily nitrogen and phosphorus-in water starts a process called eutrophication . Algae feed on the nutrients, growing, spreading, and turning the water green. Algae blooms can smell bad, block sunlight, and even release toxins in some cases.
Detailed explanation-2: -The overgrowth of algae consumes oxygen and blocks sunlight from underwater plants. When the algae eventually dies, the oxygen in the water is consumed. The lack of oxygen makes it impossible for aquatic life to survive.
Detailed explanation-3: -Eutrophication is the process in which the water body becomes overly enriched with nutrients, leading to an increase in the production of algae and macrophytes.
Detailed explanation-4: -Sometimes an aquatic ecosystem receives a large input of a limiting nutrient-for example, runoff from heavily fertilized fields. The result of this runoff can be an algal bloom-a dramatic increase in the amount of algae and other primary producers due to the increase in nutrients.