Free Environment and Atmosphere MCQs with Answers

251. Basidiospores are considered to be a major source of ___________?

• A. airborne allergens
• B. water borne allergens
• C. animal faeces
• D. bio-weapon

Explanation: Basidiospores are reproductive spores released by fungi such as mushrooms and bracket fungi, and they can become airborne. Inhalation of these spores may trigger respiratory allergies.

252. The species that flower are called ______________?

• A. Gymnosperms
• B. Bryophytes
• C. Angiosperms
• D. Algae

Explanation: Angiosperms are flowering plants whose seeds are enclosed within fruits. Gymnosperms produce exposed seeds, while bryophytes and algae do not form true flowers.

253. The instrument that measures temperature, pressure, and humidity at various altitudes in the atmosphere ___________?

• A. Barograph
• B. Radiosonde
• C. Aneroid barometer
• D. Altimeter

Explanation: A radiosonde is carried upward by a weather balloon and transmits measurements of temperature, pressure, and humidity at different altitudes. A barograph records pressure, whereas an altimeter mainly indicates altitude.

254. Melanoma (skin cancer) is associated with ______________?

• A. ozone accumulation
• B. ozone depletion
• C. acid rain
• D. allergens

Explanation: Ozone depletion allows more ultraviolet-B radiation to reach Earth's surface, increasing the risk of DNA damage and skin cancers such as melanoma. Ozone accumulation in the stratosphere is protective rather than harmful in this context.

255. The earth's atmosphere is divided into layers based on the vertical profile of __________?

• A. Air pressure
• B. Air temperature
• C. Air density
• D. Wind speed

Explanation: The atmosphere is divided into the troposphere, stratosphere, mesosphere, thermosphere, and exosphere mainly according to how temperature changes with altitude. Pressure and density also change vertically, but they are not the basis of this standard layering.

256. Barnacles growing on the back of whale is an example for ________________?

• A. mutualism
• B. parasitism
• C. amensalism
• D. commensalism

Explanation: Barnacles gain transport and access to food while the whale is generally neither helped nor harmed, making this commensalism. Mutualism would benefit both organisms, whereas parasitism harms the host.

257. Fine organic or inorganic particles suspended in air is called _______________?

• A. particulate pollutant
• B. gaseous pollutant
• C. aerosol
• D. none of these

Explanation: An aerosol is a suspension of fine solid particles or liquid droplets in a gas such as air. Particulate pollutant describes harmful particles specifically, while aerosol is the broader physical term used here.

258. Fog that most often forms as warm rain falls into a cold layer of surface air is called ______________?

• A. Radiation fog
• B. Evaporation (mixing) fog
• C. Advection fog
• D. Upslope fog

Explanation: Warm raindrops evaporate as they fall into colder surface air, adding moisture that may reach saturation and form evaporation or mixing fog. Radiation fog forms mainly when the ground cools by night-time radiation.

259. When oil and gas resources are burnt they kill many forests and lakes by ________________ ?

• A. deforestation
• B. water pollution
• C. acid rain
• D. forest fire

Explanation: Burning fossil fuels releases sulfur dioxide and nitrogen oxides, which react in the atmosphere to form acids. Their deposition damages forests and acidifies lakes, producing acid rain.

260. The pyramid of energy in any ecosystem is _________?

• A. Always upright
• B. May be upright or invented
• C. Always inverted
• D. Always Circle

Explanation: An energy pyramid is always upright because energy is lost as heat at each trophic transfer, leaving progressively less energy for higher consumers. Unlike some pyramids of numbers or biomass, it cannot be inverted.