Daily Quiz: UPSC Prelims Marathon – December 29

Statement 1 is incorrect. Loam is soil composed mostly of sand (particle size > 63 µm), silt (particle size > 2 µm), and a smaller amount of clay (particle size < 2 µm). By weight, its mineral composition is about 40–40–20% concentration of sand-silt-clay, respectively.

Statement 2 is correct. Clay type soil, organic content, and soil structure influence soil water retention.  The maximum amount of water that a given soil can retain is called field capacity, whereas a soil so dry that plants cannot liberate the remaining moisture from the soil particles is said to be at wilting point.

Statement 3 is correct. Capillary action is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. Capillaries are most effective in Loam Textured soil.

Aquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes.

A xerophyte is a species of plant that has adapted to survive in an environment with little liquid water, such as a desert or an ice- or snow-covered region in the Alps or the Arctic.

The plants live in high temperature throughout the year are called megatherms. These plants are found in equatorial and tropical rain- forests.

Mesophytes are terrestrial plants which are adapted to neither a particularly dry nor particularly wet environment.

A biochore is a subdivision of the biosphere consisting of biotopes that resemble one another and thus are colonized by similar vegetation.

Statement 1 is incorrect. An ecological niche is the smallest unit of vegetation having internal homogeneity and adaptation to its environment. It is the role and position a species has in its environment; how it meets its needs for food and shelter, how it survives, and how it reproduces. A species niche includes all of its interactions with the biotic and abiotic factors of its environment.

Statement 2 is correct. Natural grass fires are evidently more important for the ecology of savannas. The savannas are actually controlled and today managed by fire and grazing pressures. Periodic fires in semi-arid regions can lead to older tufts of grass disappearing, thereby making room for younger grasses.

Statement 1 is incorrect. The inner planets (in order of distance from the sun, closest to furthest) are Mercury, Venus, Earth and Mars. After an asteroid belt comes the outer planets, Jupiter, Saturn, Uranus and Neptune.

Statement 2 is correct. Due to higher inclination of axis, it is also known as ‘Lying Planet’. Uranus revolves the sun from east to west. Its atmosphere is composed of Hydrogen, Helium and Methane. It has 5 rings around it like Saturn (having 7 rings). This planet has 27 natural satellites. The Sun rises in its west and sets in its east.

Statement 3 is correct. Venus is the only planet whose period of rotation (243 days) is longer than the period of revolution (225 days) around the sun.

Statement 1 is incorrect. Troposphere is the hottest part of the atmosphere because it is heated by the Earth’s surface. It is the nearest atmospheric layer of earth’s surface.

Statement 2 is correct. The ozone layer or ozone shield is a region of Earth’s stratosphere that absorbs most of the Sun’s ultraviolet (UV) radiation. The ozone layer absorbs 97 to 99 percent of the Sun’s medium-frequency ultraviolet light.

Statement 3 is correct. The tropopause is the boundary in the Earth’s atmosphere between the troposphere and the stratosphere. It is a thermodynamic gradient stratification layer, marking the end of troposphere.

The Kuroshio is a warm ocean current on the west side of the North Pacific Ocean.

The Gulf Stream, together with its northern extension the North Atlantic Drift, is a warm and swift Atlantic ocean current that originates in the Gulf of Mexico and stretches to the tip of Florida, and follows the eastern coastlines of the United States and Newfoundland before crossing the Atlantic Ocean.

Benguela Current, is a cold oceanic current that is a branch of the West Wind Drift of the Southern Hemisphere. It flows northward in the South Atlantic Ocean along the west coast of southern Africa nearly to the Equator before merging with the westward-flowing Atlantic South Equatorial Current.

The Oyashio  is a cold ocean current on the west side of the North Pacific Ocean.

Statement 1 is correct.  Dentritic is an irregular tree branch shaped pattern. Drainage which is branching or ramifying (branch out or cause to branch out) thereby giving the appearance of a tree. A dendritic pattern develops in a terrain which has uniform lithology, and where faulting and jointing are insignificant.

Statement 2 is incorrect. When a river is joined by its tributaries at almost right angles, it develops a trellis pattern. Trellis pattern develops where hard and soft rocks exist parallel to each other. Primary tributaries of rivers flow parallel to each other and the secondary tributaries join them at right angles.

Statement 3 is correct. Radial drainage patterns forms when the tributaries from a summit follow the slope downwards and drain down in all directions. A good example of a radial drainage pattern is provided by the rivers originating from the Amarkantak Mountain.