Environmental Science Practice Questions
20 free Environmental Science practice questions for the Static GK. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which layer of the atmosphere contains the ozone layer that protects Earth from harmful ultraviolet radiation?
- A Stratosphere
- B Troposphere
- C Mesosphere
- D Thermosphere
Correct answer: Stratosphere
The stratosphere sits above the troposphere and contains the ozone layer. This layer absorbs 97 to 99 percent of the Sun's medium-frequency ultraviolet light.
What is the primary greenhouse gas emitted through human activities such as deforestation and burning fossil fuels?
- A Methane
- B Nitrous Oxide
- C Ozone
- D Carbon Dioxide
Correct answer: Carbon Dioxide
Carbon dioxide (CO2) is the most significant greenhouse gas contributing to global warming. It is released primarily through the combustion of coal, oil, and natural gas.
The process by which a body of water becomes overly enriched with minerals and nutrients, leading to excessive growth of algae, is called:
- A Eutrophication
- B Nitrification
- C Salinization
- D Bioaccumulation
Correct answer: Eutrophication
Eutrophication is often caused by runoff containing fertilizers or sewage. The resulting 'algal blooms' deplete oxygen in the water, killing fish and other aquatic life.
Which of the following is an example of a 'non-point source' of water pollution?
- A An industrial discharge pipe
- B A sewage treatment plant outlet
- C An oil tanker spill
- D Agricultural runoff
Correct answer: Agricultural runoff
Non-point source pollution comes from many diffuse sources rather than a single specific location. Rainwater or snowmelt moving over the ground picks up pollutants and deposits them into water bodies.
The 'Minamata Disease' was caused by the consumption of fish contaminated with which heavy metal?
- A Lead
- B Cadmium
- C Arsenic
- D Mercury
Correct answer: Mercury
Minamata disease is a neurological syndrome caused by severe mercury poisoning. It was first discovered in Minamata City, Japan, in 1956 due to industrial wastewater discharge.
Which international agreement, signed in 1987, aims to phase out the production of substances that deplete the ozone layer?
- A Kyoto Protocol
- B Paris Agreement
- C Basel Convention
- D Montreal Protocol
Correct answer: Montreal Protocol
The Montreal Protocol is considered one of the most successful environmental treaties. It specifically targeted chlorofluorocarbons (CFCs) and other ozone-depleting substances.
The term 'Biomagnification' refers to the increasing concentration of a substance in the tissues of organisms at higher:
- A Altitudes
- B Trophic levels
- C Temperatures
- D Salinity levels
Correct answer: Trophic levels
Biomagnification occurs when toxins like DDT or mercury move up the food chain. Because predators eat many prey items, the toxin concentration increases at each successive level.
Which gas is primarily responsible for the phenomenon known as 'Acid Rain'?
- A Carbon Monoxide
- B Sulfur Dioxide
- C Argon
- D Helium
Correct answer: Sulfur Dioxide
Sulfur dioxide (SO2) and nitrogen oxides (NOx) react with water and oxygen in the atmosphere to form sulfuric and nitric acids. This results in precipitation with a low pH that can damage forests and aquatic ecosystems.
What is the main purpose of a 'Electrostatic Precipitator' in a thermal power plant?
- A To increase the boiler's energy efficiency
- B To help cool down the high-pressure steam
- C To remove particulate matter from flue gas
- D To generate magnetic fields in the turbine
Correct answer: To remove particulate matter from flue gas
Electrostatic precipitators use static electricity to remove dust and smoke particles from exhaust gases. This significantly reduces air pollution emitted from industrial chimneys.
Which ecosystem is often referred to as the 'Lungs of the World' due to its massive oxygen production and carbon storage?
- A The Arctic Tundra
- B The Sahara Desert
- C The Amazon Rainforest
- D The Great Barrier Reef
Correct answer: The Amazon Rainforest
The Amazon rainforest plays a vital role in regulating the Earth's climate and cycle. It absorbs vast amounts of carbon dioxide and releases oxygen through photosynthesis.
What does the 'AQI' stand for in environmental monitoring?
- A Atmospheric Index
- B Air Quality Index
- C Aqueous Index
- D Acidic Quantity Index
Correct answer: Air Quality Index
The Air Quality Index is a tool used by government agencies to communicate to the public how polluted the air currently is. It tracks major pollutants like ground-level ozone and particulate matter.
Which of the following is a 'primary pollutant'?
- A Ozone (Ground-level)
- B Smog
- C Carbon Monoxide
- D Acid Rain
Correct answer: Carbon Monoxide
A primary pollutant is emitted directly from a source, such as a tailpipe or chimney. Secondary pollutants, like ozone, form in the atmosphere through chemical reactions between primary pollutants.
The 'Itai-Itai' disease, first reported in Japan, was caused by chronic poisoning of which element?
- A Lead
- B Cadmium
- C Mercury
- D Arsenic
Correct answer: Cadmium
Itai-Itai disease causes severe bone softening and kidney failure. It was caused by cadmium poisoning due to mining activities that contaminated river water used for rice farming.
What is the term for the variety of life in the world or in a particular habitat or ecosystem?
- A Biosphere
- B Biodiversity
- C Biomass
- D Biogeography
Correct answer: Biodiversity
Biodiversity encompasses the variety of species, genetic variations within those species, and the complex ecosystems they form. High biodiversity is a sign of a healthy environment.
Which of the following energy sources is considered 'Carbon Neutral'?
- A Coal
- B Natural Gas
- C Biomass
- D Nuclear
Correct answer: Biomass
Biomass is theoretically carbon neutral because the CO2 released during burning was recently absorbed by the plants while they were growing. However, this depends on sustainable harvesting and regrowth.
The 'Earth Summit' 1992, which led to the creation of the Convention on Biological Diversity, was held in:
- A Kyoto, Japan
- B Paris, France
- C Rio de Janeiro
- D Stockholm, Sweden
Correct answer: Rio de Janeiro
The United Nations Conference on Environment and Development (UNCED), also known as the Rio Summit, was a major milestone in global environmental policy and sustainable development.
Which type of radiation is trapped by greenhouse gases, leading to the greenhouse effect?
- A Ultraviolet radiation
- B Infrared radiation
- C X-rays
- D Gamma rays
Correct answer: Infrared radiation
The Sun's energy enters the atmosphere as short-wave radiation. The Earth absorbs this and re-emits it as long-wave infrared radiation (heat), which greenhouse gases then trap.
What is the primary cause of the 'dead zone' in the Gulf of Mexico?
- A Illegal and unregulated deep-sea mining operations
- B Multiple large accidental offshore oil spills
- C Nutrient-rich runoff from the Mississippi River
- D Decades of unsustainable commercial overfishing
Correct answer: Nutrient-rich runoff from the Mississippi River
Excess nitrogen and phosphorus from fertilizers used in the Midwest flow down the Mississippi. This causes massive algal blooms that deplete oxygen, creating a hypoxic zone where marine life cannot survive.
In the '3Rs' of waste management, which of the following is considered the most effective for the environment?
- A Recycle
- B Reuse
- C Restore
- D Reduce
Correct answer: Reduce
The hierarchy is 'Reduce, Reuse, Recycle.' Reducing waste at the source is the most effective strategy because it eliminates the need for resource extraction, energy for manufacturing, and disposal.
Which chemical was primarily responsible for the thinning of eggshells in birds of prey, leading to its ban in the 1970s?
- A BPA
- B Dioxin
- C Glyphosate
- D DDT
Correct answer: DDT
DDT is a persistent organic pollutant that interferes with calcium metabolism in birds. This caused their eggshells to become so thin that they would break during incubation.