World Geography - 3 (Gen. Studies)

Igneous rocks are also called ‘primary rocks’ because they were the first ones to be formed.
‘Extrusive igneous rock’ is the name given to magma erupting and solidifying on reaching the earth’s surface. As magma cools down rapidly on reaching the earth’s surface, so these rocks are very fine-grained.
Basalt is a typical example of extrusive igneous rocks.

The first three are sedimentary soils; quartzite is a metamorphic rock.

Equinox occurs when the Sun is vertically above the Equator.

The Taiga (boreal forest) biome is located between the temperate grasslands to the south and the tundra to the north. This forms a natural latitudinal progression from warmer grasslands through coniferous forests to Arctic tundra. The other options pair tundra with climates not adjacent to taiga belts.

Coniferous forests, also known as taiga or boreal forests, are the primary source of commercial lumber worldwide. These forests contain softwood trees like pine, spruce, and fir that grow in relatively pure stands, making them ideal for large-scale logging operations. The wood is used for construction, paper production, and various industrial applications.

Modern biodiversity conservation recognizes diversity at all levels: genetic (within species), species (between species), and ecosystem (across habitats). All three levels are interconnected and essential for comprehensive conservation efforts.

The Mediterranean climate is characterized by hot, dry summers and mild, wet winters, due to subtropical high pressure in summer and westerly winds in winter. This pattern is distinct from monsoon systems (summer rain) or regions with year-round rainfall.

Option 3 and 4 is correct because equatorial climates are characterized by consistent high temperatures (no cold winters or hot summers) and afternoon convectional showers. They have very small diurnal (daily) temperature ranges due to high cloud cover and humidity. Statements 1 and 2 are incorrect - equatorial regions don't experience seasonal temperature extremes.

Isopleths are the lines that join places of equal value of a particular phenomenon or product in uniform.

Karaganda is a major coal-mining city located in north-central Kazakhstan, part of the former Soviet Union's industrial heartland. Kazakhstan possesses significant coal deposits, and Karaganda was one of the USSR's primary coal production centers. Azerbaijan, Uzbekistan, and Georgia are other former Soviet republics but not known for Karaganda's coal mines.

Sericulture (silk farming) is traditionally practiced in China, India, Japan, and South Korea - not Poland. Poland's climate is unsuitable for mulberry trees (silkworm food source). France is indeed known for viticulture (winemaking), Netherlands for horticulture (flowers/glasshouses), and Japan for pisciculture (fish farming).

Occidental refers to Western culture and civilization. Among the options, North-Western Europe represents the core of Western/occidental culture, which includes countries like Britain, France, Germany, and Scandinavia. The other options represent non-Western cultural regions.

In the Tundra region, the harsh climate (permafrost, short growing season) makes agriculture impossible. While all options describe tundra conditions, 'infertile dissected terrain' is the most direct explanation for why hunting and fishing become the primary livelihood - the land itself cannot support cultivation. Sparse population is a consequence, not a cause.

When traveling along the South American coast from Chile (west coast) to Brazil (east coast), you must pass through the Strait of Magellan at the southern tip of the continent. The strait separates mainland South America from the Tierra del Fuego archipelago. Cook Strait is in New Zealand, Bass Strait in Australia, Torres Strait between Australia and New Guinea.

A continental shelf is the submerged edge of a continent that gradually slopes from the shoreline to a drop-off point (usually around 200 meters deep), after which the sea floor slopes steeply down to the abyssal plain. It is NOT a mountain range, raised land, or plateau - those are terrestrial features. Option C accurately describes the gentle slope followed by steep descent characteristic of continental shelves.

Ocean salinity is highest in sub-tropical regions (around 20°-30° latitude) due to high evaporation rates exceeding precipitation. The equatorial region has lower salinity due to high rainfall, polar regions have low salinity from ice melt, and tropical regions are too broad - the specific maximum is in sub-tropical zones.

Kuroshio is a warm ocean current that flows in the western North Pacific Ocean, similar to the Gulf Stream in the Atlantic. The other options are all cold currents: Peruvian (Humboldt) flows up the west coast of South America, Labrador flows south along the coast of Newfoundland, and Canary flows along the northwest coast of Africa.

Alluvial soil is formed by accumulated sediments transferred by the rivers and rapids, so it is amongst the most fertile soils. Alluvial soils are well suited to irrigation which helps in raising a number of crops like rice, jute, sugarcane, wheat, cotton, maize, oil seeds, fruits and vegeta­bles.

Marble is a metamorphic rock formed from the metamorphism of limestone, not a sedimentary rock. Limestone and sandstone are classic sedimentary rocks formed from compressed sediments. The question asks which is NOT sedimentary, making marble the correct answer.

In a folded mountain region, the typical pattern is anticlinal ridges and synclinal valleys. However, when erosion is more rapid on the ridges than valleys, the relief can invert - creating synclinal ridges and anticlinal valleys. This is known as Ridge and Valley Landscape or Inversion of Relief, commonly seen in the Appalachians. The other terms describe different coastal or erosional features.

Playas are flat, dust-covered areas in deserts that form in the lowest points of interior drainage basins. They are ephemeral lakes that fill with water after rare rainfall and dry up to form hard-packed clay or salt surfaces. While sand dunes are iconic desert features, playas are actually more commonly encountered across desert landscapes as they form in any topographic low. Pediments and pediplains are also desert features but less common.

Correct answer is (3). 

Parabolic dunes are formed when vegetation partially covers the sand surface, anchoring the dune arms while the center remains mobile. This creates a U-shaped dune with the horns pointing upwind (opposite to barchans). Barchans are crescent-shaped dunes without vegetation, seifs are longitudinal dunes, and levees are river deposits, not dune types.

Hurricanes are the specific name for cyclonic storms that occur in the North Atlantic Ocean, particularly in the West Indies and Gulf of Mexico region. The same storm is called a typhoon in the western Pacific and simply a cyclone in the Indian Ocean.

The epicentre is the point on Earth's surface directly above the focus (hypocentre), which is the actual location inside Earth where the earthquake originates. The epicentre is therefore the first point on the surface to experience earthquake waves, not the focus/hypocentre which is underground.

The temperature at Earth's core is estimated to be approximately 5,430°C, similar to the surface of the Sun. This extreme heat is primarily due to: (1) residual heat from Earth's formation (accretion and differentiation), (2) heat from radioactive decay of elements like uranium, thorium, and potassium, and (3) latent heat from solidification of the inner core.

Poland has experienced the most severe forest damage from acid rain in Europe, particularly in the Sudeten Mountains and Krkonose regions. Heavy industrialization combined with high sulfur dioxide emissions from coal burning, combined with geographical factors that trap pollutants, caused extensive forest dieback in Poland - more than Italy, Spain, or most other European countries.

The Conrad Discontinuity (named after S. Connard) is a boundary within the continental crust that separates the upper continental crust (felsic, granitic rocks) from the lower continental crust (more mafic rocks). It occurs at depths of 15-20 km and is detected by seismic velocity changes. The Mohorovicic discontinuity separates crust from mantle, Gutenberg separates mantle from core, and the core-mantle boundary separates outer core from inner core.

Edward Suess classified Earth's interior into three compositional layers: Sial (silica + aluminum, the upper continental crust), Sima (silica + magnesium, the oceanic crust and lower continental crust), and Nife (nickel + iron, the core). Mohorovicic discovered the Moho discontinuity, Gutenberg discovered the core-mantle boundary, and Connard identified the Conrad discontinuity within the crust.