Daily Prelims MCQs — Science, Technology, Environment and Geography — 22nd July 2025

Welcome to today’s handpicked set of Multiple-Choice Questions (MCQs) from the Science, Technology, Environment and Geography — crafted specially for the UPSC Prelims! These questions aren’t just a quiz — they’re a smart way to see how current affairs connect with core concepts, just like UPSC asks in the exam.

Each question is based on recent news and backed by clear explanations to help you build strong links between dynamic events and static knowledge.

Today’s topics include: Space Missions, Biofuels, Deepfakes, Rare Earth Elements, GLP-1, Microgravity, Paris Agreement, Space Re-entry, Sustainable Development, Swachh Survekshan, Mining, Climate Finance, India Environment Policy and more...

Click Here to read the Monthly Current Affairs Pointers (CAP).

QUESTION 1

Identify which of the following rare earth elements are vital components used in electric motors, braking mechanisms, smartphones, and missile technologies:

1. Samarium

2. Gadolinium

3. Terbium

4. Dysprosium

Select the correct option from the codes below:

(a) 1 and 2 only

(b) 2, 3 and 4

(c) 1 and 4 only

(d) 1, 2, 3 and 4

Answer (d)

Explanation:

China dominates over 90% of the world’s magnet processing industry, supplying materials critical to sectors like automotive manufacturing, household appliances, and clean energy solutions.

Among these essential rare earth elements are samarium, gadolinium, terbium, and dysprosium. These metals play key roles in the functioning of electric motors, braking systems, smartphones, and missile technologies, making all four indispensable for these applications.

QUESTION 2

Regarding microgravity, consider the following statements:

1. Astronauts tend to suffer from space sickness during the initial days spent in microgravity.

2. Prolonged exposure to microgravity trains the brain to ignore signals from the outer ear.

Which of the above statements is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer (a)

Explanation:

When astronauts first enter microgravity, many experience space sickness because their brains receive conflicting signals about gravity and acceleration from the inner ear — a key organ for balance on Earth. This confusion leads to symptoms like nausea and disorientation, making statement 1 is incorrect.

However, microgravity causes the brain to disregard signals from the inner ear, not the outer ear. This adjustment helps astronauts adapt in space but poses challenges upon return to Earth, where they often struggle with balance and mobility. Therefore, statement 2 is incorrect.

For example, astronauts like Shubanshu Shukla and his team, who stayed for about 18 days aboard the International Space Station, typically face milder symptoms compared to those on longer missions.

Post-mission, astronauts undergo physical reconditioning to manage difficulties such as impaired balance, visual focus issues, spinal changes, and higher injury risks due to their time spent in microgravity.

QUESTION 3

With respect to the re-entry process of a spacecraft into Earth's atmosphere, consider the following statements:

1. A spacecraft undergoes acceleration due to friction during re-entry.

2. The spacecraft descends vertically at a 90-degree angle toward Earth.

Which of the above statements is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer (d)

Explanation:

During re-entry, a spacecraft actually slows down due to the frictional forces it encounters in the atmosphere, resulting in deceleration rather than acceleration. Additional mechanisms are necessary to reduce its speed further to safe levels. Thus, statement 1 is incorrect.

One common method to achieve this speed reduction involves the deployment of parachutes. For instance, the Dragon spacecraft first releases two drogue parachutes at an altitude near 18,000 feet to stabilize the vehicle and reduce speed. Later, at about 6,500 feet, these are replaced by four main parachutes that slow the spacecraft further.

Moreover, a spacecraft does not fall straight down vertically at a 90-degree angle. Instead, it follows a shallow descent path, covering distances of 5,000 to 7,000 kilometers from re-entry to landing. During this phase, the speed gradually decreases to roughly 25-30 km/h, which ensures a safe splashdown, often in the ocean. Hence, statement 2 is also incorrect.

QUESTION 4

Which country has put forward a proposal to utilize copyright law as a tool to combat deepfake content?

(a) Australia

(b) China

(c) Denmark

(d) Norway

Answer (c)

Explanation:

Denmark has suggested a novel extension to its copyright legislation to include protections for individuals' facial features, appearance, and voice. This initiative aims to address the growing issue of deepfake media, which is becoming increasingly widespread online.

The proposed legal change would prohibit the distribution of deepfake content featuring someone without their permission. This would enable affected individuals to demand the removal of such manipulated content from digital platforms and pursue legal remedies and compensation, paralleling traditional copyright protections designed for creative works.

Deepfakes represent synthetic media that create highly convincing images, videos, or audio clips of people seemingly performing actions or making statements they never actually did, raising significant concerns around misinformation and privacy.

QUESTION 5

Regarding GLP-1 (Glucagon-Like Peptide-1), consider the following statements:

1. It functions as both an incretin hormone and a neurotransmitter.

2. It is released from the small intestine and the hindbrain after food intake.

3. It acts on the pancreas by promoting insulin secretion and suppressing glucagon release to regulate blood glucose levels.

How many of these statements are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

Answer (c)

Explanation:

GLP-1 plays dual roles as an incretin hormone and a neurotransmitter, making statements 1 and 2 correct. After a meal, GLP-1 is secreted by cells in the small intestine and also by the hindbrain.

Once released, it travels to the pancreas where it helps regulate blood sugar by enhancing insulin secretion and inhibiting glucagon production—a process known as the incretin effect. This effect is glucose-dependent, occurring primarily when blood sugar levels are elevated, confirming statement 3.

Beyond its pancreatic actions, GLP-1 also influences brain regions involved in appetite regulation, signaling feelings of fullness to help control food intake. Additionally, GLP-1 receptors are present in several other organs like the kidneys, liver, and heart, where GLP-1 exerts beneficial effects. However, its key functions in controlling blood sugar and body weight are primarily through the pancreas and the brain.

QUESTION 6

What does the term ‘Tunguska explosion’ of 1908 refer to?

(a) An unsuccessful nuclear test

(b) A deadly experiment involving radioactive Polonium

(c) An impact event caused by an asteroid

(d) A supernova resulting from colliding stars

Answer (c)

Explanation:

Around 66 million years ago, an asteroid roughly 10 kilometers in diameter collided with Earth, releasing energy equivalent to 10 billion Hiroshima bombs. This massive impact created a crater over 150 kilometers wide and drastically altered the planet’s climate in a short time. While such massive impacts are rare, smaller asteroid events occur more frequently.

One such event was the Tunguska explosion in 1908, which devastated more than 2,000 square kilometers of forest in Siberia. On June 30 of that year, eyewitnesses in the sparsely populated region observed a bright fireball streaking across the sky, followed by a massive explosion. The blast caused widespread forest fires and flattened trees for miles around, consistent with an asteroid airburst in the Earth’s atmosphere, as confirmed by NASA.

QUESTION 7

Consider the following statements:

I. Returning astronauts from space typically involves landing in the ocean.

II. Due to water’s low viscosity and high density, it offers significant cushioning during splashdown, which, while not perfectly smooth, sufficiently reduces impact forces to protect the spacecraft, its cargo, and crew.

Which of the following is correct?

(a) Both I and II are true, and II explains I

(b) Both I and II are true, but II does not explain I

(c) I is true, but II is false

(d) I is false, but II is true

Answer (a)

Explanation:

The recent Axiom-4 mission, which included Indian astronaut Shubhanshu Shukla and three others, ended with a splashdown in the Pacific Ocean after approximately 20 hours of travel from the International Space Station. Ocean landings remain the preferred method to safely return astronauts to Earth, despite alternatives like runway landings that resemble aircraft touchdowns. These alternatives, however, require more advanced technology and tend to be more expensive.

Landing in water is generally safer, even at high speeds—such as the 25-30 km/h speed at splashdown for the Axiom-4 capsule. Water’s relatively low viscosity combined with its high density creates a cushioning effect. Although this doesn’t guarantee a perfectly smooth landing, it dissipates enough impact energy to protect the spacecraft’s structure, its payload, and the crew inside.

QUESTION 8

What was the primary objective of NASA’s DART (Double Asteroid Redirection Test) mission?

(a) Demonstrate technologies required for the LISA mission

(b) Use galactic pulsars as navigational reference points

(c) Monitor Earth’s climate and ocean health

(d) Validate asteroid deflection by means of a kinetic impactor

Answer (d)

Explanation:

When a potentially hazardous asteroid is identified on a collision path with Earth, early detection is critical because the sooner action is taken, the smaller the force needed to alter its trajectory. In 2022, NASA conducted the DART mission to test this planetary defense strategy. The mission involved deliberately crashing a spacecraft into a small asteroid moon to modify its orbit, providing the first practical demonstration that altering an asteroid’s course through a kinetic impact is feasible.

As stated by NASA, DART was the inaugural mission focused solely on testing and proving the concept of asteroid deflection by physically impacting and changing an asteroid’s motion in space.

QUESTION 9

Which of the following environmental issues are consequences of illegal sand mining?

1. Decline in fertile land

2. Lowering of the groundwater table

3. Degradation of riverbeds

Choose the correct option:

(a) Only one

(b) Only two

(c) All three

(d) None

Answer (c)

Explanation:

Illegal extraction of sand leads to a multitude of environmental problems including degradation of riverbeds, destruction of aquatic habitats, increased water turbidity, and erosion of soil. It also causes the depletion of groundwater levels, loss of fertile topsoil, and damages local infrastructure. These effects collectively disturb the natural ecological balance of riverine environments, harm biodiversity, reduce water quality, and increase the risk of flooding. Therefore, all three listed damages—loss of fertile land, water table depletion, and riverbed degradation—are directly linked to illegal sand mining.

QUESTION 10

With respect to fluoride levels in groundwater, evaluate the following statements:

1. Tamil Nadu records the highest fluoride concentration in its groundwater.

2. Groundwater containing fluoride above 1.50 mg/litre is considered unsuitable for drinking.

Which of the above statements is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer (b)

Explanation:

Excessive fluoride intake can lead to health problems such as skeletal fluorosis, increased dental decay, and other adverse effects, especially impacting children. Although fluoride naturally occurs in groundwater due to the dissolution of fluoride-containing minerals in aquifers, the national standard sets 1.50 milligrams per litre as the maximum permissible limit for safe drinking water. Any concentration exceeding this threshold is deemed unsafe for consumption, making statement 2 correct.

Contrary to popular belief, the highest average fluoride content is not found in Tamil Nadu. Instead, regions in western India, particularly Rajasthan, exhibit higher fluoride concentrations in groundwater. Pre-monsoon and post-monsoon average fluoride levels in Rajasthan were recorded at 1.41 mg/litre and 1.44 mg/litre respectively, both close to the permissible limit. Therefore, statement 1 is incorrect.

QUESTION 11

Regarding primates, consider the following statements:

1. In many primate groups, female dominance emerges more through control over reproduction than through physical strength.

2. Male dominance is prevalent in primate societies.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer (a)

Explanation:

Recent research challenges the long-held belief that male primates predominantly dominate their groups. The study titled ‘The evolution of male-female dominance relationships in primate societies’, published in the Proceedings of the National Academy of Sciences (PNAS), reveals that male dominance is relatively uncommon across primate species. Instead, females often hold equal or greater social power.

Data from the study show that out of 151 primate groups observed, only 25 displayed clear male dominance where males won over 90% of interactions with females. Female dominance was observed in just 16 groups, while approximately 70% of groups exhibited either no clear dominance or only slight dominance differences.

Importantly, the findings highlight that female dominance is often rooted in reproductive control mechanisms rather than sheer physical strength or aggression. This overturns the assumption that force is always the basis of social power in primates.

Male dominance tends to be more visible in terrestrial species, species exhibiting significant sexual dimorphism (where males are larger and stronger), and polygynous mating systems where males compete for multiple females.

QUESTION 12

Which of the following organisms are capable of surviving at temperatures as high as 100 degrees Celsius?

1. Thermophilic microorganisms

2. Tardigrades

3. Pompeii worm

Select the correct option using the codes below:

(a) 1 and 2 only

(b) 2 only

(c) 1, 2 and 3

(d) 3 only

Answer (c)

Explanation:

Pompeii Worm: These remarkable creatures inhabit deep-sea hydrothermal vents, thriving in environments where temperatures can reach up to 105°C. The Pompeii worm benefits from a symbiotic relationship with bacteria that colonize its back, forming a protective heat shield. This mutualistic partnership enables the worm to withstand such extreme heat while providing a stable habitat for the bacteria.

Tardigrades: Often referred to as the toughest animals on Earth, tardigrades are microscopic organisms known for their extraordinary resilience. Experiments have shown they can survive a wide range of extreme conditions, including temperatures soaring to around 150°C, intense radiation, severe dehydration, and even the vacuum of outer space.

Thermophiles: This group of heat-loving microorganisms flourishes in high-temperature environments such as boiling hot springs and geysers, sometimes exceeding 120°C. A notable example is “Strain 121,” a species capable of surviving sterilization-level heat in autoclaves at 121°C.

Thus, all three—thermophiles, tardigrades, and Pompeii worms—can endure temperatures near or above 100°C.

QUESTION 13

Rat-hole mining is primarily practiced in which of the following states?

(a) Sikkim

(b) Jammu and Kashmir

(c) Kerala

(d) Meghalaya

Answer (d)

Explanation:

Rat-hole mining refers to a coal extraction technique used to access narrow, nearly horizontal coal seams. This method is particularly prevalent in Meghalaya. The term “rat-hole” describes the small, narrow tunnels dug into the earth, typically wide enough for just one miner to crawl into for coal extraction.

Miners descend into these pits using ropes or makeshift bamboo ladders. Coal is then manually excavated employing basic tools such as pickaxes, shovels, and baskets.

This form of mining poses significant environmental hazards and safety challenges. Often operating without formal regulation, these mines lack adequate ventilation, structural reinforcements, or protective gear for workers. The process also leads to detrimental impacts such as land degradation, loss of forest cover, and contamination of nearby water bodies.

QUESTION 14

Regarding biofuels, analyze the following statements:

1. Ethanol derived from sugarcane leads to net negative greenhouse gas (GHG) emissions overall.

2. The utilization of maize for biofuel production has transformed India from a net exporter to a net importer of this feed grain.

Which of the above statements is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer (a)

Explanation:

Bioethanol can be produced from various feedstocks including sugarcane, beet juice, rice, maize, and other cereal grains. Contrary to some beliefs, India’s increasing use of maize for ethanol has shifted the country’s status from being a surplus producer and exporter to becoming an importer of maize. This shift has also fueled ongoing discussions around permitting imports of genetically modified maize for ethanol manufacturing.

Globally, the United States stands as the largest ethanol producer, with production exceeding 16 billion gallons in 2024, primarily using corn as raw material. Brazil ranks second, where sugarcane is the main feedstock for ethanol production. India, too, achieved a milestone in 2022 by producing over one billion gallons of ethanol, accounting for roughly 5% of global ethanol output.

Ethanol from Brazil tends to have a smaller environmental footprint compared to the U.S. model because of its integrated system: sugarcane bagasse waste powers distilleries, molasses serves as cattle feed, surplus bagasse is compressed with binders to create boards and construction materials, and boiler ash is utilized as a phosphate source.

QUESTION 15

Under the newly introduced ‘Super Swachh League’ category in the Swachh Survekshan 2024–25 awards, which one of the following cities was not included?

(a) Ahmedabad

(b) Indore

(c) Surat

(d) Vijayawada

Answer (a)

Explanation:

In the Swachh Survekshan 2024–25 rankings, Ahmedabad emerged as the cleanest large city in the country, followed by Bhopal and Lucknow. However, some previous top-performing cities such as Indore and Surat were elevated to a distinct category known as the ‘Super Swachh League’, which was excluded from the main national ranking to honor their consistent high performance.

This newly created category aims to recognize cities that have repeatedly excelled in cleanliness parameters. It comprises:

• For cities with population above 10 lakh:

  • Indore, Surat, Navi Mumbai, and Vijayawada

• For cities with population between 3 lakh and 10 lakh:

  • Noida, Chandigarh, Mysuru, Ujjain, and Gandhinagar

Ahmedabad, although a top performer in 2024–25, was not included in this special league and was instead ranked within the regular large-city category.

QUESTION 16

Ahead of the recent climate negotiations in Bonn, India rallied the backing of fellow developing nations to push for the inclusion of a dedicated agenda item concerning the execution of Article 9.1 of the Paris Agreement.

What does Article 9.1 specifically mandate?

(a) Countries are required to undertake measures to preserve and improve natural carbon sinks and reservoirs, such as forests.

(b) Developed countries are obligated to provide financial support to developing nations to aid both climate change mitigation and adaptation, in line with their commitments under the UNFCCC.

(c) To meet long-term temperature stabilization goals, nations aim to achieve a peak in greenhouse gas emissions as early as possible.

(d) All Parties acknowledge a shared vision that highlights the importance of advancing technology development and transfer to bolster climate resilience and lower emissions.

Answer (b)

Explanation:

In a notable outcome at the Bonn climate discussions, India—supported by a coalition of developing nations—succeeded in bringing back into focus the requirement for developed countries to not only strive for but actually deliver financial assistance as mandated under Article 9.1 of the Paris Agreement.

This article legally binds developed nations to provide financial resources to assist developing countries in managing both climate mitigation and adaptation efforts. It reinforces their prior commitments under the United Nations Framework Convention on Climate Change (UNFCCC).

Furthermore, it's important to note that the Paris Agreement outlines two separate but connected financial obligations for developed countries:

• Under Article 9.1, they are required to provide finance.

• Under Article 9.3, they are expected to lead in mobilizing climate finance.

These provisions serve complementary roles. One does not substitute or override the other—both must be fulfilled independently.

Previous Daily UPSC Prelims MCQs Set

• 19th July 2025 - History & Culture MCQs

• 18th July 2025 - International Relation MCQs

• 17th July 2025 - Polity MCQs

• 16th July 2025 - Economy MCQs

Previous Week Current Affairs MCQs Set

• 21st July 2025 - Current Affairs MCQs

• 14th July 2025 – Current Affairs MCQs

• 7th July 2025 – Current Affairs MCQs

• 30th June 2025 - Current Affairs MCQs

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