The most effective indoor radon mitigation is:
Option B
A fan-driven system vents soil gases before they enter the building. Sealing cracks helps but is insufficient alone. Testing is essential in high-radon areas.
---
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No verified paper has been uploaded for PMS Paper Screening Test 2008 MCQs yet. The MCQs below are drawn from the Screening Test subject category.
A fan-driven system vents soil gases before they enter the building. Sealing cracks helps but is insufficient alone. Testing is essential in high-radon areas.
---
Algal blooms are a **symptom and driver** of eutrophication—nutrient enrichment of waters. Blooms deplete oxygen upon decay, causing fish kills and biodiversity loss. They can also produce toxins harmful to humans and wildlife.
---
Here is your full list of **MCQs** formatted as per your preferred structure — with **correct answers** and **explanations**.
---
### **1. Causative organisms of Malaria**
**Options:**
a) Bacteria
b) Virus
c) Parasitic organism _Plasmodium_
d) Fungi
**Correct Answer:**
**c) Parasitic organism _Plasmodium_**
**Explanation:**
Malaria is caused by a protozoan parasite of the genus _Plasmodium_, transmitted by female _Anopheles_ mosquitoes.
---
### **2. What is a Carcinogen?**
**Options:**
a) Drugs for curing infectious diseases
b) Antibiotics
c) Cancer-causing agent
d) Immunity booster
**Correct Answer:**
**c) Cancer-causing agent**
**Explanation:**
A carcinogen is any substance, organism, or agent that promotes the formation of cancer.
---
### **3. Largest preventable cause of cancer**
**Options:**
a) Tobacco smoking and chewing
b) Egg consumption
c) Air pollution
d) Alcohol
**Correct Answer:**
**a) Tobacco smoking and chewing**
**Explanation:**
Tobacco use (smoking and chewing) is the single largest preventable cause of cancer worldwide.
---
### **4. What is Bagasse? What is it used for?**
**Options:**
a) Sugarcane waste – to make paper
b) Vegetable waste – for compost
c) Liquid waste – as fertilizer
d) Animal dung – for biogas
**Correct Answer:**
**a) Sugarcane waste – to make paper**
**Explanation:**
Bagasse is the fibrous residue left after extracting juice from sugarcane. It's widely used to make paper and biofuel.
---
### **5. What is Deep Ecology?**
**Options:**
a) Protecting nature for its own sake
b) Protecting forests for humans
c) Ecology of forest
d) Technology in ecology
**Correct Answer:**
**a) Protecting nature for its own sake**
**Explanation:**
Deep ecology is an environmental philosophy that recognizes the inherent worth of all living beings regardless of their utility to humans.
---
### **6. The inherent ability of organisms to reproduce and multiply is called:**
**Options:**
a) Repetition
b) Biotic potential
c) Carrying capacity
d) None
**Correct Answer:**
**b) Biotic potential**
**Explanation:**
Biotic potential is the maximum reproductive capacity of an organism under optimal environmental conditions.
---
### **7. Birth rate is called:**
**Options:**
a) Mortality
b) Vital index
c) Natality
d) None
**Correct Answer:**
**c) Natality**
**Explanation:**
Natality is the birth rate—number of births per unit of population over time.
---
### **8. Photochemical smog is also called:**
**Options:**
a) Tokyo smog
b) London smog
c) Los Angeles smog
d) None
**Correct Answer:**
**c) Los Angeles smog**
**Explanation:**
Photochemical smog, typical of urban areas with high sunlight and vehicle emissions, is nicknamed “Los Angeles smog.”
---
### **9. The combustion of waste in the absence of oxygen is called:**
**Options:**
a) Haemolysis
b) Pyrolysis
c) Hydrolysis
d) None
**Correct Answer:**
**b) Pyrolysis**
**Explanation:**
Pyrolysis is the thermal decomposition of materials at high temperatures in the absence of oxygen.
---
### **10. What is NIHL?**
**Options:**
a) Noise-induced hearing loss
b) Water pollution
c) Air pollution
d) None
**Correct Answer:**
**a) Noise-induced hearing loss**
**Explanation:**
NIHL refers to hearing damage caused by prolonged exposure to high levels of noise.
---
### **11. What is deforestation?**
**Options:**
a) Product of forest
b) Destruction of forest
c) Forest protection
d) None
**Correct Answer:**
**b) Destruction of forest**
**Explanation:**
Deforestation is the removal or clearing of forested land, usually for agriculture or urban development.
---
### **12. Killing of animals disturbs:**
**Options:**
a) Good for ecosystem
b) Good for man
c) The balance of nature
d) None
**Correct Answer:**
**c) The balance of nature**
**Explanation:**
Killing of animals disrupts food chains and ecological balance, leading to biodiversity loss.
---
### **13. Deforestation generally decreases:**
**Options:**
a) Global warming
b) Drought
c) Soil erosion
d) Rainfall
**Correct Answer:**
**d) Rainfall**
**Explanation:**
Deforestation reduces transpiration and cloud formation, leading to decreased rainfall over time.
---
### **14. What is meant by Oceanography?**
**Options:**
a) Study of marine habitat
b) Study of freshwater
c) Study of soil
d) None
**Correct Answer:**
**a) Study of marine habitat**
**Explanation:**
Oceanography is the scientific study of oceans, including marine organisms, currents, and ecosystems.
---
### **15. North American grasslands are called:**
**Options:**
a) Pampas
b) Prairies
c) Savannah
d) None
**Correct Answer:**
**b) Prairies**
**Explanation:**
Prairies are temperate grasslands found in North America.
---
### **16. African grasslands are called:**
**Options:**
a) Prairies
b) Pampas
c) Savannah
d) None
**Correct Answer:**
**c) Savannah**
**Explanation:**
Savannahs are tropical grasslands with scattered trees found mainly in Africa.
---
### **17. Green plants are absent in deep sea. Why?**
**Options:**
a) Light is absent
b) High pressure
c) Low temperature
d) Great depth
**Correct Answer:**
**a) Light is absent**
**Explanation:**
Photosynthesis cannot occur in the deep sea due to the absence of sunlight, which green plants require.
---
### **18. What is desertification?**
**Options:**
a) Conversion of forest into desert
b) Conversion of cropland into desert
c) Conversion of grassland into desert
d) All of the above
**Correct Answer:**
**d) All of the above**
**Explanation:**
Desertification is the degradation of land in arid areas due to deforestation, overgrazing, and poor land management.
---
### **19. Infection of HIV is usually detected by which test?**
**Options:**
a) ELISA test
b) Hybridization
c) Gram staining
d) None
**Correct Answer:**
**a) ELISA test**
**Explanation:**
The ELISA (Enzyme-Linked Immunosorbent Assay) is a standard test used to detect HIV antibodies in blood.
---
Here is your latest set of MCQs formatted with **options, correct answers**, and **explanations**—as per your preferred style. This can be considered **Set-9**.
---
### **1. The first global environmental protection treaty, “The Montreal Protocol,” was signed on September 26,**
**Options:**
a) 1985
b) 1990
c) 1981
d) 1987
**Correct Answer:**
**d) 1987**
**Explanation:**
The Montreal Protocol was signed on September 26, 1987, to phase out substances that deplete the ozone layer, including CFCs.
---
### **2. The basic unit of the biosphere is:**
**Options:**
a) Biome
b) Biotope
c) Medium
d) None
**Correct Answer:**
**a) Biome**
**Explanation:**
A biome is a large ecological area on the Earth’s surface with flora and fauna adapting to their environment; it is considered the basic unit of the biosphere.
---
### **3. The excessive greenhouse effect is referred to as:**
**Options:**
a) Acid rain
b) Global warming
c) Air pollution
d) None
**Correct Answer:**
**b) Global warming**
**Explanation:**
An enhanced greenhouse effect leads to global warming—an increase in Earth's average surface temperature.
---
### **4. The "Use and Disuse" theory was proposed by:**
**Options:**
a) Lamarck
b) Stebbins
c) Darwin
d) Dobzhansky
**Correct Answer:**
**a) Lamarck**
**Explanation:**
Jean-Baptiste Lamarck proposed that traits used more frequently become stronger, and those not used diminish over generations.
---
### **5. The heating of Earth’s atmosphere due to trapped radiation is known as:**
**Options:**
a) Global warming
b) Glass-house effect
c) Thermal effect
d) Greenhouse effect
**Correct Answer:**
**d) Greenhouse effect**
**Explanation:**
Greenhouse gases trap infrared radiation from Earth, warming the atmosphere—a phenomenon known as the greenhouse effect.
---
### **6. The ozone hole was first observed on:**
**Options:**
a) Antarctica
b) Africa
c) America
d) Australia
**Correct Answer:**
**a) Antarctica**
**Explanation:**
The ozone hole was first detected over Antarctica in the early 1980s, largely due to the accumulation of CFCs.
---
### **7. Heating of the atmosphere by radiation accelerates the process of:**
**Options:**
a) Condensation
b) Rain formation
c) Precipitation
d) Evaporation
**Correct Answer:**
**d) Evaporation**
**Explanation:**
Increased atmospheric heating raises surface temperatures, accelerating the evaporation of water bodies.
---
### **8. Which among the following results in the formation of soil?**
**Options:**
a) Radiation
b) Weathering
c) Erosion
d) Pollution
**Correct Answer:**
**b) Weathering**
**Explanation:**
Weathering of rocks by physical, chemical, and biological processes is the primary cause of soil formation.
---
### **9. Animals and plants are best protected in:**
**Options:**
a) Zoos
b) Botanical Gardens
c) National Parks
d) Sanctuaries
**Correct Answer:**
**c) National Parks**
**Explanation:**
National Parks provide in situ conservation—protecting animals and plants in their natural habitat.
---
### **10. The first trophic level in a food chain is occupied by:**
**Options:**
a) Green plants
b) Herbivores
c) Carnivores
d) Bacteria
**Correct Answer:**
**a) Green plants**
**Explanation:**
Producers like green plants form the first trophic level by converting solar energy into chemical energy through photosynthesis.
---
### **11. Organisms that generate energy using light are:**
**Options:**
a) Oligotrophs
b) Chemoorganotrophs
c) Chemolithotrophs
d) Photoautotrophs
**Correct Answer:**
**d) Photoautotrophs**
**Explanation:**
Photoautotrophs (like plants, algae, and cyanobacteria) use sunlight to synthesize food from CO₂ and water.
---
### **12. Land use and land cover pattern is usually studied by the technique:**
**Options:**
a) Aerial photography
b) Satellite imaging
c) Satellite imaging and GIS
d) Satellite imaging, GIS, and GPS
**Correct Answer:**
**d) Satellite imaging, GIS, and GPS**
**Explanation:**
Modern land use studies integrate satellite data with GIS (Geographic Information Systems) and GPS (Global Positioning Systems) for precise monitoring and analysis.
---
### **13. Which one of the following does not contribute to conservation of water?**
**Options:**
a) Waste water treatment
b) Wasteland development
c) Watershed protection
d) Rainwater harvesting
**Correct Answer:**
**b) Wasteland development**
**Explanation:**
Wasteland development focuses on reclaiming degraded land rather than conserving water directly.
---
### **14. The use of microorganism metabolism to remove pollutants such as oil spills in water bodies is known as:**
**Options:**
a) Detoxification
b) Bioremediation
c) Biodegradation
d) Phytoremediation
**Correct Answer:**
**b) Bioremediation**
**Explanation:**
Bioremediation involves using microbes to degrade and remove environmental pollutants, including oil spills.
---
Coal is a fossil fuel that cannot be replenished quickly. Wind, wave power, and fuel cells are renewable or sustainable technologies. Coal use contributes heavily to pollution and climate change.
---
### **1. A high Biological Oxygen Demand (BOD) indicates that:**
**Options:**
a) Water is pure
b) Absence of microbial action
c) Low level of microbial pollution
d) High level of microbial pollution
**Correct Answer:**
**d) High level of microbial pollution**
**Explanation:**
High BOD indicates a high level of organic matter in water, leading to increased microbial activity and oxygen consumption. It is a sign of polluted water.
---
### **2. The effects of radioactive pollutants depend upon:**
**Options:**
a) Rate of diffusion
b) Energy releasing capacity
c) Rate of deposition of the contaminant
d) All of these
**Correct Answer:**
**d) All of these**
**Explanation:**
The impact of radioactive substances depends on how quickly they spread (diffusion), their energy release rate (radioactivity), and how they accumulate in environments (deposition).
---
### **3. The range of normal human hearing is:**
**Options:**
a) 10 Hz to 80 Hz
b) 50 Hz to 80 Hz
c) 20 Hz to 20,000 Hz
d) 15,000 Hz and above
**Correct Answer:**
**c) 20 Hz to 20,000 Hz**
**Explanation:**
Humans typically hear sounds in the range of 20 Hz to 20,000 Hz.
---
### **4. The pollution that does not cause persistent harm to life-supporting systems is:**
**Options:**
a) Noise pollution
b) Radiation pollution
c) Organochlorine pollution
d) All of these
**Correct Answer:**
**a) Noise pollution**
**Explanation:**
Unlike chemical or radioactive pollution, noise pollution is temporary and does not persist in the environment.
---
### **5. Soaps and detergents are sources of organic pollutants like:**
**Options:**
a) Glycerol
b) Polyphosphates
c) Sulphonated hydrocarbons
d) All of these
**Correct Answer:**
**d) All of these**
**Explanation:**
These are all components or by-products in soaps and detergents that contribute to water pollution.
---
### **6. Growing agricultural crops between rows of planted trees is known as:**
**Options:**
a) Social forestry
b) Jhum
c) Taungya system
d) Agroforestry
**Correct Answer:**
**c) Taungya system**
**Explanation:**
Taungya is a form of agroforestry where crops are cultivated alongside young forest trees.
---
### **7. The main atmospheric layer near the surface of the Earth is:**
**Options:**
a) Troposphere
b) Mesosphere
c) Ionosphere
d) Stratosphere
**Correct Answer:**
**a) Troposphere**
**Explanation:**
The troposphere is the lowest atmospheric layer where weather changes occur and humans live.
---
### **8. Which one is nature’s cleaner?**
**Options:**
a) Consumers
b) Producers
c) Decomposers and scavengers
d) Symbionts
**Correct Answer:**
**c) Decomposers and scavengers**
**Explanation:**
Decomposers break down dead organisms, recycling nutrients in ecosystems.
---
### **9. Extensive planting of trees to increase forest cover is called:**
**Options:**
a) Afforestation
b) Agroforestry
c) Deforestation
d) Social forestry
**Correct Answer:**
**a) Afforestation**
**Explanation:**
Afforestation is the process of planting trees in areas not previously forested.
---
### **10. Earth Summit at Rio de Janeiro (1992) resulted in:**
**Options:**
a) Compilation of Red List
b) Establishment of biosphere reserves
c) Conservation of biodiversity
d) IUCN
**Correct Answer:**
**c) Conservation of biodiversity**
**Explanation:**
The Earth Summit emphasized global environmental protection and biodiversity conservation, leading to Agenda 21 and the Convention on Biological Diversity.
---
### **11. World Wildlife Week is observed during:**
**Options:**
a) First week of October
b) Last week of October
c) Third week of October
d) First week of September
**Correct Answer:**
**a) First week of October**
**Explanation:**
It’s celebrated in India to raise awareness about wildlife conservation.
---
### **12. The relationship between nitrogen-fixing bacteria and leguminous plants is an example of:**
**Options:**
a) Parasitism
b) Predation
c) Mutualism
d) Commensalism
**Correct Answer:**
**c) Mutualism**
**Explanation:**
Both organisms benefit—plants get nitrogen; bacteria get shelter and nutrients.
---
### **13. Algal blooms are caused by:**
**Options:**
a) Green algae
b) Blue-green algae
c) Diatoms
d) All algae
**Correct Answer:**
**b) Blue-green algae**
**Explanation:**
Blue-green algae (cyanobacteria) often bloom in nutrient-rich waters, leading to eutrophication.
---
### **14. Name the disease caused by mercury poisoning in Japan:**
**Options:**
a) Sulphur dioxide
b) Carbon dioxide
c) Methane
d) Minamata Disease
**Correct Answer:**
**d) Minamata Disease**
**Explanation:**
Caused by industrial mercury discharge into Minamata Bay, leading to neurological damage.
---
### **15. The place where the worst nuclear disaster took place:**
**Options:**
a) Washington
b) Chernobyl
c) Bhopal
d) Japan
**Correct Answer:**
**b) Chernobyl**
**Explanation:**
The Chernobyl disaster (1986) in Ukraine was the worst nuclear accident in history.
---
### **16. What is meant by GM foods?**
**Options:**
a) Growth Modified foods
b) Genetically Modified foods
c) Growth Marked foods
d) Government Managed foods
**Correct Answer:**
**b) Genetically Modified foods**
**Explanation:**
GM foods are derived from organisms whose DNA has been altered for desired traits.
---
### **17. Expand GIS:**
**Options:**
a) Geographical Information System
b) Geological Information System
c) Global Information Satellite
d) Geoinformation Standards
**Correct Answer:**
**a) Geographical Information System**
**Explanation:**
GIS is used to capture, store, analyze, and manage spatial or geographic data.
---
### **18. MoFE stands for:**
**Options:**
a) Ministry of Forest and Energy
b) Ministry of Fuel and Energy
c) Ministry of Forest and Environment
d) Ministry of Fossil Energy
**Correct Answer:**
**c) Ministry of Forest and Environment**
**Explanation:**
Responsible for formulating policies on forest, climate, and environmental management.
---
### **19. Sedimentation is a:**
**Options:**
a) Primary water treatment
b) Secondary water treatment
c) Tertiary water treatment
d) None
**Correct Answer:**
**a) Primary water treatment**
**Explanation:**
It involves removing suspended solids from water by gravity.
---
### **20. Deer is a:**
**Options:**
a) Producer
b) Primary consumer
c) Secondary consumer
d) Decomposer
**Correct Answer:**
**b) Primary consumer**
**Explanation:**
Deer feed on plants and are herbivores, placing them at the second trophic level.
---
### **21. Some species of plants and animals that are extremely rare and occur only in few locations are called:**
**Options:**
a) Endemic
b) Endangered
c) Vulnerable
d) Rare
**Correct Answer:**
**a) Endemic**
**Explanation:**
Endemic species are restricted to a particular geographic region and found nowhere else.
---
### **22. Which of the following can be e-waste?**
**Options:**
a) Plastic
b) Paper
c) Industrial effluent
d) Mobile phone
**Correct Answer:**
**d) Mobile phone**
**Explanation:**
E-waste refers to discarded electronic items like phones, computers, and batteries.
---
### **23. Death rate of the population is called:**
**Options:**
a) Mortality
b) Viability
c) Natality
d) Vitality
**Correct Answer:**
**a) Mortality**
**Explanation:**
Mortality refers to the number of deaths in a population over a certain period.
---
### **24. Forests growing in high rainfall areas are:**
**Options:**
a) Evergreen forests
b) Tropical forests
c) Conifers
d) Thorn forests
**Correct Answer:**
**a) Evergreen forests**
**Explanation:**
Evergreen forests are dense and lush, found in regions with high annual rainfall.
---
### **25. The species that flower are called:**
**Options:**
a) Gymnosperms
b) Bryophytes
c) Angiosperms
d) Pteridophytes
**Correct Answer:**
**c) Angiosperms**
**Explanation:**
Angiosperms are flowering plants and produce seeds enclosed within fruits.
---
### **26. Trees that shed their leaves during winter and summer are:**
**Options:**
a) Evergreen
b) Coniferous
c) Deciduous
d) Tropical
**Correct Answer:**
**c) Deciduous**
**Explanation:**
Deciduous trees lose their leaves seasonally to conserve water and energy.
---
### **27. Thorn forests are found in:**
**Options:**
a) High rainfall areas
b) Regions with low temperatures
c) Arid/semi-arid regions
d) Coastal areas
**Correct Answer:**
**c) Arid/semi-arid regions**
**Explanation:**
Thorn forests are adapted to dry climates and are found in low rainfall zones.
---
### **28. Which of the following is an example of a bottom feeder?**
**Options:**
a) Catfish
b) Frog
c) Snail
d) Duck
**Correct Answer:**
**a) Catfish**
**Explanation:**
Catfish are bottom-dwelling fish that feed on debris and small organisms on the substrate.
---
### **29. The drug morphine is extracted from which plant?**
**Options:**
a) Cocoa
b) Belladonna
c) Opium poppy
d) Cinchona
**Correct Answer:**
**c) Opium poppy**
**Explanation:**
Morphine is a powerful painkiller derived from the latex of the opium poppy (_Papaver somniferum_).
---
### **30. Which plants die after flowering?**
**Options:**
a) Lotus
b) Bamboo
c) Chrysanthemum
d) Peepal
**Correct Answer:**
**b) Bamboo**
**Explanation:**
Bamboo is semelparous—it flowers once (often after decades) and then dies.
---
### **31. The marine tortoise known for 'arribada' is:**
**Options:**
a) Olive Ridley
b) Star tortoise
c) Travancore tortoise
d) Green sea turtle
**Correct Answer:**
**a) Olive Ridley**
**Explanation:**
‘Arribada’ is a mass nesting event seen in Olive Ridley turtles along coasts like Odisha.
---
### **32. Largest reptile in the world is:**
**Options:**
a) Dragon
b) Anaconda
c) Crocodile
d) Monitor lizard
**Correct Answer:**
**c) Crocodile**
**Explanation:**
The saltwater crocodile (_Crocodylus porosus_) is the largest living reptile.
---
### **33. Who stated at the Stockholm Conference (1972) that “poverty is the greatest polluter”?**
**Options:**
a) Indira Gandhi
b) Mahatma Gandhi
c) Rajiv Gandhi
d) E.F. Schumacher
**Correct Answer:**
**a) Indira Gandhi**
**Explanation:**
Indira Gandhi highlighted the link between poverty and environmental degradation at the UN conference.
---
### **34. Expansion of SPCA:**
**Options:**
a) Society for the Protection of Common Animals
b) Society for the Prevention of Cruelty to Animals
c) Society for the Prohibition of Cruelty to Animals
d) Society for the Protection of Community Animals
**Correct Answer:**
**b) Society for the Prevention of Cruelty to Animals**
**Explanation:**
SPCA is a charitable organization dedicated to preventing animal abuse.
---
### **35. ‘Smog’ is a mixture of:**
**Options:**
a) Smoke and fog
b) Snow and fog
c) Snow and dust
d) Sulphur dioxide and fog
**Correct Answer:**
**a) Smoke and fog**
**Explanation:**
Smog is formed when smoke from pollution combines with fog, reducing air quality.
---
### **36. Anthrax disease is caused by:**
**Options:**
a) Virus
b) Bacteria
c) Protozoa
d) Helminths
**Correct Answer:**
**b) Bacteria**
**Explanation:**
Anthrax is caused by _Bacillus anthracis_, a spore-forming bacterium.
---
### **37. A hawk that eats a frog is a:**
**Options:**
a) Producer
b) Primary consumer
c) Secondary consumer
d) Tertiary consumer
**Correct Answer:**
**d) Tertiary consumer**
**Explanation:**
Hawk eats a frog (which eats insects), making it a tertiary-level consumer in the food chain.
---
### **38. Moisture in the air is known as:**
**Options:**
a) Water
b) Fog
c) Snow
d) Humidity
**Correct Answer:**
**d) Humidity**
**Explanation:**
Humidity refers to the amount of water vapor present in the air.
---
### **39. World Forest Day is celebrated on:**
**Options:**
a) 21st March
b) 5th June
c) 1st December
d) 7th June
**Correct Answer:**
**a) 21st March**
**Explanation:**
Observed to raise awareness about the importance of all types of forests.
---
### **40. An example of lotic water is:**
**Options:**
a) Pond
b) River
c) Lake
d) Reservoir
**Correct Answer:**
**b) River**
**Explanation:**
Lotic systems refer to flowing water bodies, such as rivers and streams.
---
### **41. Superbugs are:**
**Options:**
a) Synthetic bugs
b) Bacteria
c) Radio nucleotides
d) Industrial pollutants
**Correct Answer:**
**b) Bacteria**
**Explanation:**
Superbugs are bacteria resistant to multiple antibiotics, posing a major health threat.
---
### **42. Torrey Canyon is famous for:**
**Options:**
a) Gulf War
b) Industries
c) Electric Potential
d) Oil Spillage
**Correct Answer:**
**d) Oil Spillage**
**Explanation:**
The _Torrey Canyon_ was an oil tanker responsible for a massive oil spill near the UK in 1967.
---
### **43. Red Sea is named after:**
**Options:**
a) Red algae
b) Blue-green algae
c) Oil spillage
d) Brown algae
**Correct Answer:**
**a) Red algae**
**Explanation:**
The sea occasionally appears reddish due to the bloom of _Trichodesmium erythraeum_, a type of red algae.
---
Absolutely! Here's **Part 3 – Final** of **Set-7**, continuing with properly formatted **MCQs**, **correct answers**, and **explanations**.
---
### **44. Aquatic life is damaged by:**
**Options:**
a) Sound pollution
b) Air pollution
c) Thermal pollution
d) All of these
**Correct Answer:**
**d) All of these**
**Explanation:**
All these forms of pollution can harm aquatic organisms—thermal pollution affects oxygen solubility, sound pollution disturbs marine life, and air pollution contributes to acid rain.
---
### **45. Minamata disease is caused by:**
**Options:**
a) Air pollution
b) Water pollution
c) Marine pollution
d) All of these
**Correct Answer:**
**b) Water pollution**
**Explanation:**
Minamata disease was caused by mercury-contaminated water due to industrial discharge into Minamata Bay in Japan.
---
### **46. Complex, interlinked food chains are called:**
**Options:**
a) Food web
b) Food network
c) Trophic levels
d) Food pyramid
**Correct Answer:**
**a) Food web**
**Explanation:**
A food web shows the interconnected feeding relationships between organisms in an ecosystem.
---
### **47. Acid rain mainly results from:**
**Options:**
a) Sulphur dioxide
b) Carbon dioxide
c) Carbon monoxide
d) Ammonia
**Correct Answer:**
**a) Sulphur dioxide**
**Explanation:**
SO₂ and NOx gases released into the atmosphere form acids with water vapor, resulting in acid rain.
---
### **48. Which among the following is an example of ex-situ conservation?**
**Options:**
a) Zoological parks
b) Wildlife sanctuaries
c) National parks
d) Reserved forests
**Correct Answer:**
**a) Zoological parks**
**Explanation:**
Ex-situ conservation involves protecting species outside their natural habitat, such as in zoos, seed banks, or botanical gardens.
---
### **49. The word "Biophilia" was coined by:**
**Options:**
a) Dr. Hackel
b) Dr. Johanssen
c) Dr. Benjamine
d) Edward O. Wilson
**Correct Answer:**
**d) Edward O. Wilson**
**Explanation:**
Biologist E.O. Wilson coined the term "Biophilia" to describe humans' innate affinity for nature.
---
### **50. The book _Silent Spring_ was written by:**
**Options:**
a) Madhav Gadgil
b) Anil Agarwal
c) Rachel Carson
d) E.O. Wilson
**Correct Answer:**
**c) Rachel Carson**
**Explanation:**
Published in 1962, _Silent Spring_ exposed the harmful effects of pesticides, especially DDT, on wildlife and ecosystems.
---
### **51. World Ozone Day is observed on:**
**Options:**
a) March 16
b) June 5
c) September 16
d) November 16
**Correct Answer:**
**c) September 16**
**Explanation:**
This day commemorates the signing of the Montreal Protocol to protect the ozone layer.
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### **52. Abiotic is a:**
**Options:**
a) Living component
b) Non-living component
c) Both living and non-living component
d) None of these
**Correct Answer:**
**b) Non-living component**
**Explanation:**
Abiotic factors include non-living elements like sunlight, temperature, and water that influence ecosystems.
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### **53. Lotic ecosystem refers to:**
**Options:**
a) Static water system
b) Ecosystem of flowing water
c) Ecosystem of estuaries
d) Deep marine water system
**Correct Answer:**
**b) Ecosystem of flowing water**
**Explanation:**
Lotic ecosystems include rivers and streams, characterized by running water.
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### **54. The Red Data Book, listing endangered species, is maintained by:**
**Options:**
a) UNO
b) WHO
c) IUCN
d) WWF
**Correct Answer:**
**c) IUCN**
**Explanation:**
The International Union for Conservation of Nature (IUCN) publishes the Red List of Threatened Species.
---
### **55. Global warming is caused by:**
**Options:**
a) Greenhouse gases (GHGs)
b) CFCs
c) CH₄
d) All of the above
**Correct Answer:**
**d) All of the above**
**Explanation:**
All listed gases trap heat in the atmosphere and contribute to global warming.
---
### **56. Autotrophs are:**
**Options:**
a) Consumers
b) Herbivores
c) Saprophytes
d) Producers
**Correct Answer:**
**d) Producers**
**Explanation:**
Autotrophs like plants and algae synthesize their own food through photosynthesis and serve as the base of food chains.
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### **57. Organisms which depend on producers are called:**
**Options:**
a) Autotrophs
b) Saprophytes
c) Consumers
d) Xerophytes
**Correct Answer:**
**c) Consumers**
**Explanation:**
Consumers (heterotrophs) rely on autotrophs (producers) for food and energy.
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Awesome—continuing from **Q201** in the same format (statement, shuffled options, Correct Answer, and a 3–5 sentence explanation):
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Large particle size and wide pores in sandy soil allow rapid drainage and minimal retention. Clay holds water strongly; loam balances texture for better retention. Thus, sandy soils dry out fastest.
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The Double Asteroid Redirection Test (DART) was a NASA mission that intentionally crashed a spacecraft into the asteroid moon Dimorphos in 2022 to see if its orbit could be changed.
The Parker Solar Probe is a NASA mission launched in 2018 to study the Sun's outer corona. It has set records for being the fastest spacecraft and the one that flies closest to the Sun.
The Sun's core is its hottest region, reaching temperatures of about 15 million degrees Celsius. This is the region where nuclear fusion occurs.
Spring tides occur during New and Full Moons when the gravitational pulls of the Sun and Moon are aligned, creating the greatest difference between high and low tide.
Venus is the hottest planet in the Solar System. Its thick CO2 atmosphere creates a runaway greenhouse effect, trapping heat and raising surface temperatures to around 465°C.
In astronomy, the color of a star indicates its surface temperature. Blue and blue-white stars are the hottest, with temperatures exceeding 30,000 Kelvin, while red stars are the coolest.