DAY – 17 : Insta 75 Days Revision Plan-2026 : ENVIRONMENT & ECOLOGY

Answer:  (a)

Explanation:

• Statement I is Correct: Acid rain is indeed the result of atmospheric pollution caused by sulfur dioxide (SO2) and nitrogen oxides (NOx). While there are natural sources (such as volcanoes and lightning), the primary drivers are human activities, including the burning of fossil fuels in power plants and emissions from vehicles.
• Statement II is Correct: Once SO2 and NOx are released into the atmosphere, they do not remain in their gaseous form. Instead, they undergo chemical transformations. These gases react with water vapor (H2O), oxygen (O2), and other oxidants to form acidic compounds such as sulfuric acid and nitric acid.
• Statement I identifies the causative agents of acid rain (the gases), whereas Statement II explains the underlying mechanism through which these gases are converted into acidic compounds. Thus, Statement II directly explains how the pollutants mentioned in Statement I lead to the formation of acid rain.

Answer:  (a)

Explanation:

• Statement I is Correct: Coastal Blue Carbon ecosystems (mangroves, seagrasses, and salt marshes) are incredibly efficient at capturing carbon. While they cover less than 5% of the worlds ocean floor, they are responsible for more than 50% of all carbon storage in ocean sediments. Their sequestration rate per unit area can be up to 10 times higher than that of tropical rainforests.
• Statement II is Correct: Unlike terrestrial forests, where carbon is primarily stored in the wood and leaves (above-ground biomass), Blue Carbon ecosystems store up to 90% of their carbon in the soils and sediments (below-ground). These soils are typically anaerobic (oxygen-poor), which prevents the carbon from oxidizing and being released back into the atmosphere as CO2.
• The reason these ecosystems can sequester carbon at such high rates and for such long periods (millennia) is precisely because they move the carbon into deep, waterlogged sediments where it is locked away from the decomposition cycle. In a typical forest, when a tree dies, it rots and releases CO2; in a mangrove, the organic matter gets buried in the mud where it stays stable.

Answer:   (b)

Explanation:

A Primary Pollutant is emitted directly from a source (like a factory chimney or a vehicle exhaust) into the atmosphere. A Secondary Pollutant is not emitted directly; it forms in the air when primary pollutants react with each other or with basic atmospheric components (like water vapor or sunlight).

• Sulfur Dioxide (SO2): Primary. Emitted directly from coal combustion and smelting.
• Ground-level Ozone (O3): Secondary. It is not emitted by any tailpipe. It forms when NOx and Volatile Organic Compounds (VOCs) react in the presence of sunlight.
• Particulate Matter (PM 2.5): Primary. (Note: While some PM can form secondarily, it is fundamentally classified as a primary pollutant because it is emitted directly as soot, dust, and smoke).
• Peroxyacetyl Nitrate (PAN): Secondary. A key component of photochemical smog, formed by the reaction of hydrocarbons and nitrogen oxides.
• Nitric Oxide (NO): Primary. Emitted directly from high-temperature combustion in engines.

Answer:  (d)

Explanation:

• Statement 1 is Incorrect: There is no separate Noise (Prevention and Control of Pollution) Act, 1981. In India, noise is legally regulated as an air pollutant under the Air (Prevention and Control of Pollution) Act, 1981. The specific regulations are titled the Noise Pollution (Regulation and Control) Rules, 2000.
• Statement 2 is Correct: For Silence Zones, the permissible noise limit is indeed 50 dB(A) Leq during the day (6:00 AM to 10:00 PM) and 40 dB(A) Leq during the night (10:00 PM to 6:00 AM).
• Statement 3 is Incorrect: A Silence Zone is defined as an area up to 100 meters around hospitals, educational institutions, courts, religious places, or any other area declared as such by the competent authority. 1000 meters is an exaggeration and would cover too large an area for practical enforcement.
• Ambient Noise Standards in India (CPCB)

Answer:   (c)

Explanation:

• Statement 1 is correct: The National Ambient Air Quality Standards (NAAQS), notified by the Central Pollution Control Board, cover 12 pollutants. These include PM10, PM2.5, SO2, NO2, O3, NH3 (Ammonia), Lead, CO, Benzene, Benzo(a)pyrene, Arsenic, and Nickel. Carbon dioxide (CO2) is not included because it is a greenhouse gas, not a conventional air pollutant under NAAQS.
• Statement 2 is correct: The National Air Quality Index (AQI), launched in 2014 with the tagline One Number, One Colour, One Description, tracks 8 pollutants: PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Lead (Pb).
• Statement 3 is correct: Ground-level ozone (O3) is monitored under both frameworks. It is an important secondary pollutant that affects respiratory health and is included in both the 12-pollutant NAAQS and the 8-pollutant AQI.
• Statement 4 is incorrect: Volatile Organic Compounds (VOCs) are primary pollutants and also act as precursors to ozone formation. However, they are not included as a separate pollutant in the daily AQI calculation. They are also not listed as one standalone category in NAAQS, though specific VOCs such as Benzene are included separately.

Answer:  (d)

Explanation:

• The Bio-RIDE (Biotechnology Research Innovation and Deployment Ecosystem) scheme is a central initiative approved by the Union Cabinet to propel India’s bio-economy toward the goal of $300 billion by 2030.
• It streamlines the biotechnology sector by merging two previously separate components: Biotechnology Research and Development (R&D) and Industrial Development (ID).
• It aims to foster a seamless transition from Lab to Market by supporting basic research, nurturing startups through BIRAC (Biotechnology Industry Research Assistance Council), and scaling up biomanufacturing.
• Bio-RIDE is the primary vehicle for implementing the BioE3 Policy (Biotechnology for Economy, Environment, and Employment), which focuses on high-performance biomanufacturing to tackle climate change and resource depletion.

Answer:  (a)

Explanation:

• Statement 1 is Incorrect: While biomining in the mining industry refers to using bacteria to extract metals from ores (bio-leaching), in the context of Solid Waste Management (SWM) and Indian municipal regulations, it refers to the reclamation of old landfills (dumpsites). It is a mechanical-biological process, not a purely chemical leaching process for dry residues.
• Statement 2 is Correct: This is the core of the biomining process for legacy waste. Old waste is spread out in windrows (long rows) and treated with bio-cultures (microorganisms). These microbes speed up the aerobic decomposition of the organic fraction, effectively stabilizing the waste so it no longer produces high levels of methane or foul odors.

Answer:  (a)

Explanation:

• X-rays (3): Definitely Ionizing. They have energies in the kilo-electronvolt (keV) range. They easily strip electrons from atoms.
• Visible Light (4) & Infrared (2): Definitely Non-Ionizing. Their energy is far too low to ionize atoms; they only cause molecules to vibrate (heat) or electrons to jump to higher orbits (excitation) without leaving the atom.
• Cosmic Rays: Ionizing, Cosmic rays are high-energy particles (mostly protons) originating from outside the Solar System. Because they travel at nearly the speed of light and possess immense kinetic energy, they are highly ionizing. They can easily break chemical bonds and damage DNA.

Answer:   (d)

Explanation:

• It is the first known quadruple system where two Brown Dwarfs (failed stars) orbit two Red Dwarfs (small, faint stars).
• Brown dwarfs are objects that are too large to be planets (size of Jupiter but 13–80 times heavier) but too small to sustain the nuclear fusion of hydrogen like a normal star.
• Because all four objects formed from the same cloud of gas at the same time, it acts as a Natural Laboratory to compare how different masses evolve under the same conditions.

Answer:  (d)

Explanation:

Prime Minister of India paid tribute to the revolutionaries of the Kakori incident on its 100th anniversary, honouring their courage and sacrifice in India’s freedom struggle.

• Ashfaqulla Khan: He was one of the core planners and executors. He famously initially opposed the robbery (fearing a heavy government crackdown) but eventually joined the mission to maintain unity. He was later hanged in Faizabad Jail.
• Chandrashekhar Azad: He was the “untouchable” leader who managed the perimeter and security during the robbery. He was the only major participant who was never captured by the police in connection with this case.
• Manmathnath Gupta: He was the one who accidentally fired the shot that killed a passenger (Ahmed Ali), which escalated the case from a simple robbery to a murder trial. He was sentenced to 14 years of imprisonment.
• Rajendra Lahiri: He was the one who actually pulled the emergency chain of the 8-Down Saharanpur-Lucknow Express to bring the train to a halt at Kakori. He was later hanged in Gonda Jail.

Answer: (b) ₹1000

Solution:

Let CP = x
Marked Price = 1.5x
After 20% discount → SP = 1.5x × 0.8 = 1.2x

Profit = 1.2x − x = 0.2x

Given profit = 120
→ 0.2x = 120
→ x = 1000

Answer: (b) 50%

Solution:

Let CP of 1 kg = 100

Marked Price = 150

After 20% discount:
SP = 150 × 0.8 = 120

He gives only 800 g

Cost of 800 g = 80

Profit = 120 − 80 = 40

Profit % = (40 / 80) × 100 = 50%

Shortcut Method:

Net factor =
Markup × Discount × False weight gain

= 1.5 × 0.8 × (1000/800)
= 1.5 × 0.8 × 1.25
= 1.5

Gain = 50%

Answer: (d) 50%

Solution:

Let CP = 100
Gain = 8% → SP = 108

Let MP = x

After discounts → SP = 0.8 × 0.9 × x = 0.72x

0.72x = 108
→ x = 150

Markup = 150 − 100 = 50%

Answer: (a) ₹200

Solution:

Let CP = x
SP = 1.1x

New CP = 0.9x
New SP = 1.1x − 20

New gain = 25%
→ New SP = 1.25 × 0.9x = 1.125x

So,
1.1x − 20 = 1.125x
→ 20 = 0.025x
→ x = 200

Answer: (b)

Solution:
The passage highlights a critical distinction between economic growth and equitable development. While growth is commonly used as a measure of progress, it does not automatically improve the well-being of all sections of society. The author emphasizes that without fair distribution of resources and equal access to opportunities, economic growth can actually deepen existing inequalities. Thus, growth alone is insufficient unless accompanied by inclusivity. Option (a) is incorrect because it assumes automatic equality, (c) denies the relationship, and (d) is extreme. Therefore, option (b) correctly captures the central idea that growth without equity may increase inequality.