Category: Environmental Science MCQs

Correct Answer: C. Non-polluting and renewable

Non-polluting: Hydropower does not produce air pollution or greenhouse gas emissions during electricity generation. Unlike fossil fuels such as coal, oil, or natural gas, which release pollutants and greenhouse gases when burned, hydropower generates electricity by harnessing the kinetic energy of flowing water, typically in rivers or dams. This process does not involve combustion, so it does not emit pollutants like carbon dioxide (CO2), sulfur dioxide (SO2), nitrogen oxides (NOx), or particulate matter.
Renewable: Hydropower is considered renewable because it relies on the natural water cycle, which is continuously replenished by precipitation (rain and snow). As long as precipitation occurs, rivers will continue to flow, providing a consistent source of energy. Additionally, the water used for hydropower generation is not consumed or depleted in the process; it is simply redirected through turbines to generate electricity and then returned to the river or reservoir. This means that hydropower can be considered sustainable over the long term, as it does not deplete finite resources like fossil fuels.
Overall, hydropower is an environmentally friendly energy option that can help reduce reliance on fossil fuels and mitigate climate change by providing a clean and renewable source of electricity.

Correct Answer: B. Deforestation

Deforestation refers to the indiscriminate cutting down or removal of trees and forests, often resulting in the transformation of forested land into non-forest areas. This process can occur due to various reasons such as agricultural expansion, urbanization, logging, infrastructure development, and wildfires. Deforestation has significant environmental consequences, including habitat loss, soil erosion, disruption of ecosystems, loss of biodiversity, and contribution to climate change through the release of carbon dioxide into the atmosphere. Efforts to combat deforestation often involve measures such as reforestation (replanting trees in deforested areas), afforestation (planting trees in areas that were previously not forested), conservation initiatives, and sustainable land management practices.

Correct Answer: B. Afforestation

Afforestation is the process of planting trees or sowing seeds in a barren land devoid of any trees with the intention of creating a forest. Deforestation, on the other hand, is the removal or clearing of forests or trees from a land.

Correct Answer: B. Soil is protected against loss

The correct answer is B. Soil conservation is the process of protecting soil against loss, degradation, or erosion. This can involve various practices such as terracing, contour plowing, crop rotation, and the use of cover crops to maintain soil health and prevent erosion.

Correct Answer: D. Nudation -> invasion -> completion and coaction -> reaction -> stabilization

The correct order of basic processes involved in succession is:
D. Nudation -> invasion -> completion and coaction -> reaction -> stabilization
Nudation: This is the initial process where a new habitat becomes available, often due to disturbances such as volcanic eruptions, landslides, or glacial retreat. It exposes the substrate for colonization by organisms.
Invasion: Following nudation, pioneer species or organisms colonize the newly available habitat. These are typically fast-growing and adaptable species that can quickly establish themselves in the disturbed area.
Completion and coaction: As succession progresses, the community becomes more diverse and complex. Different species interact and compete for resources, leading to changes in species composition and community structure.
Reaction: The community undergoes further changes in response to environmental factors such as climate, soil development, or biotic interactions. These reactions may lead to further changes in species composition and community dynamics.
Stabilization: Eventually, the community reaches a relatively stable state known as the climax community. This stage is characterized by a dynamic equilibrium where the community structure and species composition remain relatively constant over time.
Therefore, the correct answer is:
D. Nudation -> invasion -> completion and coaction -> reaction -> stabilization

Correct Answer: D. Sere

The intermediate developmental phase in ecological succession is known as the “Sere.” Sere: The sere is the entire sequence of communities that successively occupy a particular site during ecological succession. It includes all the stages from pioneer species to the climax community, making it the correct term for the intermediate developmental phase.

Correct Answer: C. Carbon Dioxide Into Air

Burning fossil fuels, such as coal, oil, and natural gas, releases carbon dioxide (CO2) into the atmosphere. This is a well-established fact supported by scientific research and is a significant contributor to the greenhouse effect and climate change. Therefore, option C, “Carbon dioxide into air,” is the correct answer. C. Carbon Dioxide into Air

Correct Answer: D. Fossil

The inexhaustible forms of energy are those that can be replenished naturally and indefinitely, typically derived from renewable sources. Fossil fuels, on the other hand, are finite resources formed over millions of years and are non-renewable. Therefore, the correct answer is: D. Fossil

Correct Answer: A. Climax

Climax: This option correctly identifies the final stable community in ecological succession, which is the climax community. It represents the endpoint of ecological succession where the community reaches a state of relative stability.

Correct Answer: D. Forests

Forests (option D) are typically characterized by a complex and diverse ecosystem with multiple trophic levels. Therefore, the upright pyramid of numbers is less likely to be absent in forests compared to the other options.
The upright pyramid of numbers is more likely to be absent in aquatic ecosystems like lakes (option A) and ponds (option B), where the primary producers, such as phytoplankton, can be very abundant, supporting a large number of herbivores and subsequently carnivores. This can lead to an inverted pyramid of numbers, where the number of organisms at higher trophic levels exceeds those at lower trophic levels. Therefore, the correct answer is: D. Forests