[DAY 12] 60 DAY RAPID REVISION (RaRe) SERIES for UPSC Prelims 2023 – ENVIRONMENT, CURRENT AFFAIRS & CSAT TEST SERIES!

Solution: (d)

Explanation:

• Boreal biome soils are characterized by thin podzols which are acidic and mineral deficient. It is because the weathering of rocks proceeds slowly in cold environments and the litter is decomposed very slowly. The soil is acidic because of a large amount of water movement through the soil without a significant amount of evaporation and essential nutrients are leached beyond the reach of roots.Hence statement 1 is correct.
• The predominant vegetation in the Taiga biome is evergreen coniferous trees. Due to permafrost in Tundra, it is devoid of trees.Hence statement 2 is incorrect.
• Epiphytes along with ebony and mahogany are seen in the tropical rainforest biome. Hence statement 3 is correct.
• Epiphytes are plants that grow harmlessly upon another plant and derive their nutrients and moisture from air, rain, and debris accumulating around it.

Solution: (b)

Explanation:

• The main species of tropical moist deciduous forests are teak, sal, rosewood, and jamun. Hence statement 1 is incorrect.
• The main species of tropical thorn forests are neem, cactus, and spurge. Hence statement 2 is incorrect.
• The main species of sub-tropical pine forests are chir, oak, pine, and rhododendron. Hence statement 3 is correct.
• The main species of tropical dry deciduous forests are acacia, red sanders, and satinwood. Hence statement 4 is correct.
• The main species of tropical wet evergreen forests are white cedar, mahogany, and meusa.
• The main species of tropical semi-evergreen forests are laurel, rosewood, and thorny bamboo.

Solution: (b)

Explanation:

Deforestation is the felling of trees as a result of urbanization, industrialization, mining, use of wood for domestic purposes, shifting cultivation, etc.

Logging – 10 – 15%

Small-holder agriculture – 35 – 45%

Large-scale agriculture – 15 – 20%

Cattle pasture – 20 – 25%

Other – 5%

Hence option b is correct.

Solution: (b)

Explanation:

• Bonn Challenge is a global goal to restore 150 million hectares of degraded land by 2020 and 350 million hectares by 2030. Hence statement 1 is incorrect.
• Bonn Challenge was launched by the Government of Germany and IUCN in 2011.
• India joined the challenge in 2015 and it has set the target of restoring 26 million hectares by 2030.
• State of India’s Environment 2019 shows that 30% of India’s total geographical area is being affected by land degradation.82% of these degraded land lies in just nine states: Rajasthan, Maharashtra, Gujarat, Jammu & Kashmir, Karnataka, Jharkhand, Odisha, Madhya Pradesh and Telangana.Hence statement 2 is incorrect.
• LDN is a state whereby the amount and quality of land resources, necessary to support ecosystem functions and services and enhance food security, remains stable or increases within specified temporal and spatial scales and ecosystems.
• Sustainable Development Goal 15 (SDG 15 or Global Goal 15) is about “Life on land”. One of the 17 Sustainable Development Goals established by the United Nations in 2015, the official wording is: “Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss”Hence statement 3 is correct.

Solution: (b)

Explanation:

• The Indian State of Forest Report 2021 for the first time has recorded the forest cover in tiger reserves, tiger corridors, and the Gir forest area. The Total Forest and Tree cover is 24.62% of the geographical area of the country.The total forest cover is 7,13,789 sq km which is 21.71% of the geographical area of the country.The tree cover is 2.91% of the geographical area of the country.Forest cover in tiger corridors has increased by 0.32% between 2011-2021.Forest cover in tiger corridors has decreased by 0.04% between 2011-2021.Hence statement 1 is correct.
• Madhya Pradesh has the largest area-wise forest cover. Madhya Pradesh>Arunachal Pradesh>Chhattisgarh>Odisha>Maharastra – Area-wise forest cover.Hence statement 2 is incorrect.
• The Forest Survey of India (FSI) conducts this exercise every two years. Hence statement 3 is incorrect.
• The Forest Survey of India, is an organization under the Ministry of Environment, Forest and Climate Change(MoEFCC).
• Mizoram with 84.53 % has the highest percentage wise forest cover,while Nagaland is 5^th with 73.90% .Hence statement 4 is incorrect.

Solution: (d)

Explanation:

• Lentic ecosystems include all ecosystems with static or still water. Ex: Lakes and Ponds. Hence statement 1 is correct.
• Lotic ecosystems include all fast-moving water bodies. Ex: Rivers and Streams. Hence statement 2 is correct.
• Lentic ecosystems are also called the lacustrine ecosystem. Hence statement 3 is incorrect.
• Lotic ecosystems are also called the riverine ecosystem. Hence statement 4 is incorrect.

Solution: (d)

Explanation:

• Biorock refers to the substance formed by the electro-accumulation of minerals dissolved in seawater. It is also known as Seacrete or Seament. Hence statement 1 is correct.
• Biorock projects can be powered by renewable energy like windmills, photovoltaic solar panels, and tidal current generators. This enables their construction in areas where conventional electric power is unavailable. Hence statement 2 is correct.
• Biorock technology helps in coral restoration.
• It is a method that applies safe, low-voltage electrical currentsthrough seawater, causing dissolved minerals to crystallize on structures, growing into a white limestone (CaCo3) similar to that which naturally makes up coral reefs and tropical white sand beaches. Hence statement 3 is correct.

Solution: (c)

Explanation:

• Eutrophication is the enrichment of natural waters with inorganic nutrients, increasing the production of algae and macrophytes.
• Anthropogenic or “cultural eutrophication” is often a much more rapid process in which nutrients are added to a water body from a wide variety of polluting inputs including untreated or partially treated sewage Hence statement 1 is incorrect.
• When compared to anthropogenic eutrophication, the natural eutrophication process is substantially slower. Hence statement 2 is correct.
• Eutrophication leads to the transformation of the water body from an aquatic ecosystem to a terrestrial ecosystem. It leads to excess growth of algae blooms in the water body.Algal blooms obstruct sunlight penetration, resulting in the mortality of aquatic plants and, as a result, oxygen replenishment.It also leads to an increase in invasive species in the water bodies due to an increase in nutrient levels in the water bodies.Hence statement 3 is incorrect.

Solution: (b)

Explanation:

• Coral reefs in India are found in a lot of areas including the Gulf of Kutch, Gulf of Mannar, Palk Bay, Andaman & Nicobar, and Lakshadweep Islands.
• Patches of coral reefs are also found in Ratnagiri, Malvan, Redi, South Bombay, and at the Gaveshani Bank located in the west of Mangalore. Hence statement 1 is incorrect.
• India has all three major prevailing types of coral reefs – atolls, fringing reefs, and barrier reefs. Hence statement 2 is correct.
• Fringing reefs evolve and develop near the continent and remain close to the coastline. These reefs are separated from the coastline by small, shallow lagoons. They are the most commonly found reefs in the world.
• Barrier reefs are found offshore on the continental shelf. They usually run parallel to the coastline at some distance. A deep and wide lagoon is located between the coastline and the barrier reef.
• Atolls are formed on mid-oceanic ridges. They are shaped circularly or elliptically and are surrounded by seas on all four sides and have shallow waters in the center called a lagoon.

Solution: (c)

Explanation:

• The estuary ecosystem is an area where a river meets the sea and is subject to tidal variations. It is a place where freshwater mixes with salty ocean water.It is formed due to various factors like rising sea levels, glacial processes, and tectonic processes. Hence statement 1 is correct.
• Estuaries are greatly influenced by tidal action. They are periodically washed by sea water once or twice a day based on the number of tides.In some narrow estuaries, tidal bores are significant. Tidal bores cause great damage to the estuarine ecology. Hence statement 2 is incorrect.
• It is biologically the most productive area where diverse animals are found as it gets nutrients from both fresh and marine water. Hence statement 3 is correct.

Solution: (a)

Explanation:

• The mangrove ecosystem forms the best example of ecotone as they grow in estuaries, low-lying coasts, and mudflats. Hence statement 1 is correct.
• An ecotone is an area that acts as a boundary or a transition between two ecosystems.
• They are halophytes adapted to anoxic conditions. Hence statement 2 is correct.
• Halophytes mean salt-tolerant trees and anoxic mean low oxygen conditions of waterlogged mud.
• They produce pneumatophores to overcome the respiration problem.
• The Mangroves for the Future initiative is led by the IUCN and UNDP. It promotes investment in coastal ecosystem conservation and India is part of it. Hence statement 3 is incorrect.

Solution: (c)

Explanation:

• Black corals can be found growing both in shallow and deep waters. They can live for over 4,000 years and are branched and look like feathers, fans, or bushes, while others are straight like a whip.Black corals are filter feeders and eat tinyzooplankton that is abundant in deep waters.Hence statement 1 is incorrect.
• Hard corals extract calcium carbonate from seawater to build coral exoskeletons.Hard corals produce a rigid skeleton made of calcium carbonate (CaCO3) in a crystal form called aragonite. They are the primary reef-building corals. Hard corals that form reefs are called hermatypic corals.Hence statement 2 is correct.
• Soft coral doesnot produce a rigid calcium carbonate skeleton. They do not form reefs, though they are present in a reef ecosystem.Soft corals are also mostly colonial; what appears to be a single large organism is a colony of individual polyps combined to form a larger structure. Visually, soft coral colonies tend to resemble trees, bushes, fans, whips, and grasses.Hence statement 3 is correct.

Solution: (b)

Explanation:

• The International Coral Reef Initiative (ICRI) is an informal partnership among nations, international organisations and non-government organisations to help protect coral reefs globally. It aims to implement Chapter 17 of Agenda 21, Aichi Target 10 of the Convention on Biological Diversity’s 10-year Strategic Plan, and other relevant internationally agreed objectives and targetsHence statement 1 is incorrect.
• It was launched at the First Conference of the Parties of the Convention on Biological Diversity, held in the Bahamas in December 1994, and subsequently announced at the high level segment of the Intersessional Meeting of the United Nations Commission on Sustainable Development in April 1995 Hence statement 2 is correct.
• ICRI was established in 1994 at the initiative of eight founding nations: Australia, France, Japan, Jamaica, the Philippines, Sweden, the United Kingdom, and the United States .ICRI now has more than 60 members including India. Hence statement 3 is incorrect.

Solution: (a)

Explanation:

• India has seven UNESCO-designated natural world heritage sites. Hence statement 1 is correct.
• Khangchendzonga National Parkis the only mixed world heritage site in India. Hence statement 2 is incorrect.
• The Natural World Heritage Sites in India-

1. Great Himalayan National Park Conservation Area 
2. Kaziranga National Park (1985)
3. Keoladeo National Park (1985)
4. Manas Wildlife Sanctuary (1985)
5. Nanda Devi and Valley of Flowers National Parks (1988, 2005)
6. Sundarban National Park (1987)
7. Western Ghats (2012)

Solution: (d)

Explanation:

• Lakes are never a part of the ocean they are defined as aquatic systems on land. Even lagoons are excluded from this definition. Hence statement 1 is correct.
• The lakes which do not have any outflow and rather lose their water with evaporation are known as endorheic lakes. The aral sea and the Caspian sea both are such lakes. Hence statement 2 is correct.
• Lakes are a temporary feature and get eventually eliminated due to silting and draining.Hence statement 3 is correct.

Solution: (b)

Explanation:

Hence option b is correct.

Solution: (a)

Explanation:

• Montreux Record is aregister of wetland sites in which changes in ecological character are occurring, have occurred, or are likely to occur. Hence statement 1 is correct.
• It is maintained as part of the Ramsar List. Hence statement 2 is correct.
• Chilika lake of Odisha was on the list but it’s removed now. Hence statement 3 is incorrect.
• Currently, two wetlands of India are in Montreux record: Keoladeo National Park (Rajasthan) and Loktak Lake (Manipur).

Solution: (c)

Explanation:

• The layer from thesurface to 200 meters is known as the epipelagic zone. It is also known as the sunlight zone because this is where most of the visible light exists. Hence statement 1 is incorrect.
• The layer from 200 meters to 1,000 meters is known as the mesopelagiczone. It is sometimes referred to as the twilight zone or the midwater zone. Hence statement 2 is incorrect.
• The layer from 1,000 meters to 4,000 meters is known as the bathypelagic zone. It is referred to as the midnight zone or the dark zone. Hence statement 3 is correct.
• The layer from4,000 meters to 6,000 meters is known as the abyssal zone. Hence statement 4 is correct.
• The layer from 6,000 meters to the bottom of the deepest parts of the ocean is known as the hadalpelagic zone.

Solution: (d)

Explanation:

• Artificial lakes are often built by diverting a part of a river and storing the water in a reservoir behind a dam. They are also constructed by digging land or by using dykes to enclose the water.
• The artificial lakes in India –
• Chembarambakkam Lake
• Bhojtal Lake
• Hussain Sagar Lake
• Gobind Sagar Lake
• Jaisamand Lake

Hence option d is correct.

Solution: (c)

Explanation:

• The grassland ecosystem is found in both tropical and temperate climates where the rainfall is insufficient to support tree growth. Hence statement 1 is incorrect.
• They are an intermediate stage in ecological succession as they encompass a portion of the land at all altitudes and latitudes when climatic and soil conditions prevent tree growth. Hence statement 2 is correct.
• Jaguars, African wild dogs, pronghorns, plains bison, mountain plover, African elephant, Sunda tiger, black rhinos, white rhinos, savanna elephants, bigger one-horned rhinos, Indian elephants, swift foxes, and black-footed ferrets are found in grasslands. Hence statement 3 is correct.

Solution (a)

Explanation:

• Combined Maritime Forces is a 34-nation maritime partnership based in Bahrain that undertakes counter-terrorism, counter-piracy and regional cooperation. Hence statement 1 is correct.
• It is commanded by U.S. Navy Vice Admiral. Hence statement 2 is correct.
• 34 member nations: Australia, Bahrain, Belgium, Brazil, Canada, Denmark, Egypt, France, Germany, Greece, Italy, Iraq, Japan, Jordan, Republic of Korea, Kuwait, Malaysia, the Netherlands, New Zealand, Norway, Pakistan, The Philippines, Portugal, Qatar, Saudi Arabia, Seychelles, Singapore, Spain, Thailand, Turkey, UAE, United Kingdom, United States and Yemen. Hence statement 3 is not correct.

Source: CLICK HERE

Solution (c)

Explanation:

• The Indian Bureau of Mines (IBM) established in 1948, is a multi-disciplinary government organisation under the Department of Mines, Ministry of Mines, engaged in promotion of conservation, scientific development of mineral resources and protection of environment in mines other than coal, petroleum & natural gas, atomic minerals and minor minerals. Hence statement 1 is not correct.
• The objective of the IBM is to promote systematic and scientific development and optimum utilisation of mineral resources of the country (both on-shore and off-shore). Hence statement 2 is correct.
• Headed by the Controller General, IBM has six technical divisions with its head quarters at Nagpur. Hence statement 3 is not correct.
• IBM has 4 Zonal Offices, 13 Regional Offices, 2 Regional Ore Dressing Laboratories and Pilot Plants spread over the Country.

Source: CLICK HERE

Solution (d)

Explanation:

• Small Cells are low-powered radio access nodes or base stations that have a coverage range from a few metres to a few hundred metres. Hence statement 1 is correct.
• They are portable, easy to deploy and help provide localised coverage. Hence statement 2 is correct.
• Small Cells are needed for deploying 5G as opposed to earlier generations such as 4G, because of the frequency. Hence statement 3 is correct.
• The higher the frequency, the lower the wavelength, which means that the distance they travel is less.
• To expedite the roll out of 5G, telecom operators in the country will leverage street furniture such as poles, advertisement hoardings and bus shelters for deploying the Small Cells.

Source: CLICK HERE

Solution (d)

Explanation:

• To augment skill training in tribal communities for their inclusive and sustainable growth, National Skill Development Corporation (NSDC) in partnership with Seva Bharti and Yuva Vikas Society, launched the second phase of Grameen Udyami Project. Under the initiative, the endeavour is to multiskill India’s youth and impart functional skills to them for enabling livelihoods. Hence statement 1 is correct.
• It aims to train 450 tribal students in Madhya Pradesh and Jharkhand. The project is being implemented in six states— Maharashtra, Rajasthan, Chhattisgarh, Madhya Pradesh, Jharkhand, and Gujarat. Hence statement 2 is not correct.
• Grameen Udyami Yojana is implemented under Sansadiya Parisankul Yojana. Hence statement 3 is correct.

Source: CLICK HERE

Solution (a)

Explanation:

• It is part of the Nicobar Islands and is located to the south of Sentinel Island. Hence statement 1 is correct. Hence statement 1 is correct.
• The United States National Aeronauticsand Space Administration (NASA) recently highlighted the loss of mangrove cover on Katchal island, a part of India’s Nicobar archipelago.
• The mangrove cover on Katchal will not come back as it lacks propagules.
• A propagule is a vegetative structure that can become detached from a plant and give rise to a new plant. Hence statement 2 is not correct.

Source: CLICK HERE

Solution (d)

Explanation:

Speed of athlete,

= 200m/24 secs

= (200*18)/(5*24)

= 30km/hour

Solution (b)

Explanation:

Let the distance between school and home be x km.

The difference of time when A goes school to school with these two different speed is 10 min

= 10/60 hour

Now,

x/3 – x/4 = 10/60

Or, x/12 = 1/6

Or, x = 12/6

= 2km

Solution (c)

Explanation:

Time taken by Kamal

= 100/ (18*5)/18

= 20 seconds

Hence, Time taken by Bimal

20+5=25seconds

So, Bimal’s speed

= 100/25

= 4

= (4*18)/5

= 14.4 kmph

Solution (d)

Explanation:

Time taken to complete the revolution:

A → 12/4 = 3 hrs

B → 12/3 = 4 hours

C → 12*(2/3) = 8 hrs

Required time,

= LCM of 3, 4, 8.

= 24 hours.

Solution (a)

Explanation:

The ‘birthday problem’ talked about in this paragraph serves to highlight the fact that coincidences are more common and more probable than we think. Option a states this idea clearly, and is hence the correct option.

Options b and d are similar. They talk of the significance of / meaning attributed to coincidences. This is not what the paragraph discusses.

While it is true that the paragraph explains the probability of coincidences occurring, that is not the main idea of the paragraph. So, option b is not the right one.