UPSC Static Quiz – Geography : 22 May 2026

Solution: B

• Statement 1 is correct. The Kuiper Belt is a disc-shaped region beyond the orbit of Neptune, extending roughly from 30 to about 50 astronomical units from the Sun. It contains icy bodies and remnants from the early Solar System and is widely accepted as the principal source of short-period comets, particularly Jupiter-family comets whose orbital periods are less than about 200 years.
• Statement 2 is correct. Pluto resides in the Kuiper Belt and is one of many Kuiper Belt Objects. Its reclassification as a dwarf planet by the International Astronomical Union in 2006 was primarily because it does not clear its orbital neighbourhood of other debris.
• Statement 3 is incorrect. The Asteroid Belt is located between the orbits of Mars and Jupiter, not between Jupiter and Saturn.Top of Form

Solution: A

• The Neoproterozoic Era is the youngest subdivision of the Precambrian and represents a crucial phase in Earth’s deep-time history. It witnessed major climatic events such as the “Snowball Earth” glaciations and laid the foundation for complex life, including the emergence of multicellular organisms like the Ediacaran biota. This era marks the transition from a largely microbial world to one capable of supporting more complex biological forms.
• The Paleozoic Era follows the Neoproterozoic and is characterized by a dramatic diversification of life, especially during the Cambrian Explosion. Marine invertebrates flourished, fishes evolved, and life gradually colonized land in the form of plants, amphibians, and early reptiles. This era ended with the Permian mass extinction, the most severe extinction event in Earth’s history.
• Next comes the Mesozoic Era, often called the “Age of Reptiles.” It saw the dominance of dinosaurs, the breakup of the supercontinent Pangaea, and the first appearance of birds and mammals. Flowering plants also evolved during this era, significantly altering terrestrial ecosystems.
• The Cenozoic Era is the youngest era and continues to the present day. It is marked by the diversification and dominance of mammals and birds, major mountain-building events, repeated ice ages, and ultimately the evolution of humans. This era shapes the modern physical and biological environment of Earth.

Solution: C

• Option (a): The ‘Age of Reptiles’ refers to the Mesozoic Era, specifically the Jurassic and Cretaceous periods, not the Carboniferous.
• Option (b): The rapid diversification of life occurred in the Cambrian Period (start of Paleozoic), roughly 541 million years ago.
• Option (c): The Carboniferous Period (part of the Paleozoic Era) is famously named after the vast carbon reserves formed during this time. Massive tropical swamp forests covered much of the land; the vegetation from these forests did not decay fully but was buried to form the world’s major coal deposits.
• Option (d): The extinction of non-avian dinosaurs (K-Pg event) occurred at the end of the Cretaceous Period (end of Mesozoic), roughly 66 million years ago.

Solution: B

• Statement 1 is Correct: Batholiths are the largest intrusive forms, composed typically of granite. They cool very slowly at great depths and are exposed on the surface only after significant erosion removes the overlying rock (e.g., Wicklow Mountains).
• Statement 2 is Incorrect: A Laccolith is a dome-shaped or mushroom-shaped intrusion with a flat base. It forces the overlying strata to arch upward. The description “saucer-shaped body formed in synclinal basins” refers to a Lopolith, not a Laccolith.
• Statement 3 is Correct: Dykes are discordant intrusions that cut across the bedding planes of existing rock (vertical/steep). When the surrounding softer rock erodes, dykes often stand out as natural walls.

Solution: B

• Statement I is Correct: Crossing the IDL from East to West (e.g., USA to Japan) means moving “into the future.” You skip a calendar day (e.g., go from Monday directly to Wednesday, or lose the 24 hours of Tuesday). Conversely, West to East gains a day (repeats a day).
• Statement II is Correct: The IDL has a massive deviation (hammer shape) around the Line Islands of Kiribati. This was done (in 1994) to ensure the entire country sits on the same calendar day (the western side/Asian side), making Kiribati the first nation to see the sunrise.
• Statement III is Incorrect: The IDL is not a Great Circle because it is not a straight line; it zig-zags. Furthermore, a Great Circle must pass through the center of the Earth. The 180° meridian is half a great circle, but the IDL (with deviations) is not.
• Statement II describes a geographical fact about the line’s shape. Statement I describes the temporal consequence of crossing it. While they are related to the IDL, the deviation in Kiribati (II) is not the explanation for why you lose a day crossing East-West (I); the rotation of Earth is the explanation for that. Thus, both are correct but independent facts in this context.