Environmental Science

  Unit 2: Pollution and Its Types 1. Electrostatic precipitator is used for: A) Water purification B) Air pollution control C) Soil treatment D) Noise control Answer: B 2. Water pollution is caused by: A) Industrial waste B) Sewage C) Agricultural chemicals D) All of the above Answer: D 3. BOD stands for: A) Biological Oxygen Demand B) Basic Oxygen Demand C) Bacterial Oxygen Demand D) Balanced Oxygen Demand Answer: A 4. High BOD indicates: A) Clean water B) Polluted water C) Neutral water D) Drinking water Answer: B 5. COD stands for: A) Chemical Oxygen Demand B) Carbon Oxygen Demand C) Chemical Oxide Demand D) Clean Oxygen Demand Answer: A 6. Normal pH of drinking water is around: A) 3 B) 5 C) 7 D) 10 Answer: C 7. Turbidity in water means: A) Cloudiness of water B) Color of water C) Temperature of water D) Smell of water Answer: A 8. Primary wastewater treatment mainly removes: A) Dissolved impurities B) Suspended solids ...

Unit 1: Ecosystem 1. An ecosystem consists of: A) Only plants B) Only animals C) Living and non-living components D) Only microorganisms Answer: C 2. The non-living components of an ecosystem are called: A) Biotic factors B) Abiotic factors C) Producers D) Consumers Answer: B 3. Plants in an ecosystem are known as: A) Consumers B) Producers C) Decomposers D) Parasites Answer: B 4. Animals that depend on plants for food are called: A) Carnivores B) Omnivores C) Herbivores D) Parasites Answer: C 5. Organisms that break down dead matter are called: A) Producers B) Consumers C) Decomposers D) Herbivores Answer: C 6. Which of the following is a natural ecosystem? A) Aquarium B) Crop field C) Forest D) Garden Answer: C 7. Which ecosystem is found in water? A) Desert ecosystem B) Forest ecosystem C) Aquatic ecosystem D) Grassland ecosystem Answer: C 8. The movement of carbon through living and non-living components is called: A) Nitro...

  1. Definition of Pollution and Pollutant Pollution Pollution is the undesirable change in the physical, chemical or biological characteristics of air, water or land that harms living organisms, property and the environment . 👉 Example: Smoke from vehicles mixing with air and causing breathing problems. Pollutant A pollutant is any solid, liquid or gaseous substance present in the environment at a concentration that causes harm or discomfort . 👉 Examples: Carbon monoxide, plastic waste, sewage, industrial chemicals, noise. 2. Air Pollution Definition Air pollution occurs when harmful gases, dust or smoke enter the atmosphere and reduce air quality . Classification of Air Pollutants 1. Primary Pollutants Emitted directly from sources. Carbon monoxide (CO) Sulphur dioxide (SO₂) Nitrogen oxides (NOx) 👉 Example: Exhaust gases from vehicles. 2. Secondary Pollutants Formed by chemical reactions in the atmosphere. Ozone (O₃) Photochemical smog ...

An ecosystem is a community of living organisms (plants, animals, microorganisms) interacting with the non-living environment (air, water, soil, sunlight) in a particular area. Example Forest ecosystem : Trees, animals, insects, soil, water, air Pond ecosystem : Fish, algae, insects, water, sunlight 2. Structure and Components of Ecosystem Structure of Ecosystem The ecosystem is made up of two main components : (A) Biotic Components (Living) Producers Green plants that make food using sunlight Example: Grass, trees, algae Consumers Animals that depend on plants or other animals for food Types: Primary consumers: Deer, cow Secondary consumers: Lion, tiger Tertiary consumers: Top predators Decomposers Break down dead plants and animals into nutrients Example: Bacteria, fungi (B) Abiotic Components (Non-Living) Air, water, soil Sunlight Temperature Minerals Simple Example In a garden ecosystem : Plants → Pr...