Question

Which of the following is not influenced by human activities?
A) Depletion of groundwater
B) Destruction of Mangroves
C) Increased extinction rate of species
D) None of these.

Answer 1

Various human activities have a harmful effect on the natural balance and functioning of the environment. Deforestation and the loss of habitat have become common causing a depletion in the population of various species and have to be tackled in a proper manner.

Complete answer:
Let us analyze the given options:
A) Depletion of groundwater: Groundwater is the water reservoir present below the soil. Various human activities such as the abstraction of the groundwater, its overexploitation, the building of reservoirs, and overuse of land have caused changes in groundwater levels and led to its depletion. Thus human activities cause depletion in groundwater levels.

B) Destruction of Mangroves: Increasing deforestation has led to a widespread destruction of Mangrove forests leading to a decrease in their numbers. It is also caused due to a reduction in the area occupied by wetlands by activities such as the construction of dams as well as by dumping of wastes by industries as well as sewage wastes. Thus human activities cause destruction of Mangroves.

C) Habitat destruction caused by human activities by practices such as deforestation and pollution have become the cause of extinction of a wide variety of species. Other activities such as hunting and poaching have also led to extinction of many animals. Thus human activities have led to an increased rate of extinction of species.

D) None of these: Since all the above options are affected by human activities. The above options are not influenced by human activities.

Thus by considering all the above-given options, the most appropriate answer is option D. That is, none of the options is influenced by human activities.

Note: The most dangerous effects of human activities are global warming and greenhouse effect. An increase in concentration of greenhouse gases such as carbon dioxide has increased the average temperature on Earth eventually leading to climate changes causing global warming. This has also led to depletion in the ozone layer forming holes in it allowing the harmful UV rays from the sun to reach the Earth’s surface.