Free Environment and Atmosphere MCQs with Answers

171. Which of these is a micronutrient of plants?

• A. Oxygen
• B. Nitrogen
• C. Boron
• D. Carbon

Explanation: Boron is a plant micronutrient needed only in very small quantities. Nitrogen, carbon, and oxygen are required in much larger amounts and are classified as macronutrients or structural elements.

172. An example of rhizome is_________?

• A. Carrot
• B. Tomato
• C. Ginger
• D. Garlic

Explanation: Ginger is a rhizome, a horizontally growing underground stem with nodes and buds. Carrot is a root, while tomato is a fruit and garlic is a bulb.

173. Which of the following organisms releases molecular oxygen into water?

• A. E.coli
• B. Phytoplankton
• C. Amoeba
• D. Salmonella

Explanation: Phytoplankton carry out photosynthesis in water, using light and carbon dioxide to produce food and release molecular oxygen. The other listed organisms do not normally oxygenate water through photosynthesis.

174. The process of converting wet waste to manure is___________?

• A. Metabolism
• B. Conservation
• C. Incineration
• D. Composting

Explanation: Composting uses microorganisms to decompose wet organic waste into nutrient-rich manure. Incineration burns waste, while conservation and metabolism describe broader processes rather than this waste-treatment method.

175. Which of the following pollutants in water causes "Minamata disease?

• A. Methyl Mercury
• B. Lead
• C. Salmonella
• D. Perchlorate

Explanation: Minamata disease results from methylmercury poisoning, usually after contaminated water and aquatic organisms carry mercury through the food chain. It primarily damages the nervous system.

176. A crescograph is a device for measuring the growth in __________?

• A. Micro Organism
• B. Plants
• C. Human
• D. Pollution

Explanation: A crescograph is a sensitive instrument used to measure and record very small increases in plant growth. It can detect movements that are too slow or slight to observe directly.

177. ______ soil is also called Regur soil?

• A. Desert
• B. Mountain
• C. Black
• D. Alluvial

Explanation: Regur soil is the traditional name for black soil, a clay-rich soil especially associated with cotton cultivation in parts of the Indian subcontinent. Its dark colour and moisture-retaining property distinguish it from alluvial and desert soils.

178. Which of the following noble gases is abundant in air?

• A. Neon
• B. Helium
• C. Argon
• D. Methane

Explanation: Argon is the most abundant noble gas in Earth’s atmosphere, making up about 0.93% of dry air. Neon and helium occur only in very small amounts, while methane is not a noble gas.

179. Bubo bubo is the scientific name of which of the following species?

• A. Hen
• B. Peacock
• C. Eagle
• D. Owl

Explanation: Bubo bubo is the scientific name of the Eurasian eagle-owl, one of the world’s largest owl species. The repeated genus and species names identify a biological species rather than a general bird group.

180. Which of the following flower is called Queen of Water?

• A. Rose
• B. Lilly
• C. Rafflesia
• D. Tulip

Explanation: The water lily is commonly called the Queen of Water because it grows and blooms on the surface of ponds and lakes. Rose, tulip, and Rafflesia are not aquatic water lilies.