Environmental Science MCQ – Asked in Previous Years, WBCS Mains

Answer – D. Olive Ridley
Explanation-
▪ The Olive Ridley turtle (Lepidochelys olivacea) is a species of sea turtle that can be found resting along the sea coasts of West Bengal. Olive Ridley turtles are known for their mass nesting events, called arribadas, where thousands of turtles come ashore to lay their eggs. These turtles are considered vulnerable and are protected under various conservation measures.

Answer – B. Sundari
Explanation-
▪ The mangrove species for which maximum sweet water influx is required is Sundari (Heritiera fomes). Sundari mangroves are found in the Sundarbans region, which spans across India and Bangladesh. These mangroves are adapted to brackish water environments and require a significant influx of sweet water for their growth and survival.

Answer – D. Leopard
Explanation-
▪ A black panther is a melanistic color variant of the leopard (Panthera pardus) or, less commonly, the jaguar (Panthera onca). Melanism is a genetic condition that causes an increased production of dark pigment, resulting in a black or dark-colored coat. The black panther’s appearance is due to this genetic variation, and it retains the physical characteristics and behavior of its respective species.

Answer – C. Sundarban
Explanation-
▪ The Sundarban Tiger Reserve, located in the Sundarbans National Park in West Bengal, is known as the “Kingfishers’ Paradise.” The Sundarbans is a unique mangrove ecosystem and a UNESCO World Heritage Site. It is home to the Royal Bengal Tiger, various species of birds, and diverse flora and fauna. The reserve gets its name from the abundance of kingfisher species found in the region.

Answer – C. Skin cancer
Explanation-
▪ Depletion of the ozone layer increases the incidence of skin cancer. The ozone layer in the Earth’s stratosphere plays a crucial role in absorbing the majority of the sun’s harmful ultraviolet (UV) radiation. When the ozone layer is depleted, more UV radiation reaches the Earth’s surface, increasing the risk of skin damage, including sunburns, premature aging, and skin cancer.

Answer – B. 4
Explanation-
▪ There are 4 biodiversity hotspots in India that have been recognized by the World Wildlife Fund (WWF). These are:

1. The Himalayas
2. The Indo-Burma region
3. The Western Ghats
4. Sundaland

▪ In addition to these four hotspots, there are also a number of other biodiversity-rich areas in India, such as the Sundarbans and the Terrai-Duar Savannah grasslands.

▪ The four hotspots in India are home to a vast diversity of plant and animal life, including many species that are found nowhere else in the world. They are also important for the conservation of water resources and for providing a home to indigenous peoples.

▪ The WWF has identified a number of threats to the biodiversity of these hotspots, including:
• Habitat loss and fragmentation
• Climate change
• Overexploitation of resources
• Pollution
• Invasive species

Answer –B. High diversity
Explanation-
▪ Hot spots are areas with high biodiversity and species richness. These regions are characterized by a large number of endemic species and are considered to be of significant conservation value. Hot spots often contain unique ecosystems and habitats that support a wide range of plant and animal species.

Answer – C. Semiclosed coastal body of water
Explanation-
▪ An estuary is a semiclosed coastal body of water where freshwater from rivers and streams meets and mixes with saltwater from the ocean. Estuaries are typically characterized by dynamic tidal movements and have a unique ecological structure and function. They serve as nurseries for various marine species and support diverse ecosystems.

Answer – C. MIC (Methyl Isocyanate)
Explanation-
▪ The industrial disaster in Bhopal in December 1984 was caused by the release of methyl isocyanate (MIC) gas from the Union Carbide pesticide plant. The gas leak resulted in the immediate death of thousands of people and caused long-term health effects for many others. The Bhopal gas tragedy is considered one of the world’s worst industrial disasters.

Answer – C. 6 feet
Explanation-
▪ The depth of water in a wetland typically does not exceed 6 feet. Wetlands are areas where the water table is at or near the surface, creating unique hydrological conditions that support distinct plant and animal communities adapted to wet environments.