Water & Carbon Cycle in Nature MCQs with Explanations
The Water Cycle and Carbon Cycle are important biogeochemical cycles that maintain ecological balance on Earth. Understanding these natural cycles helps explain climate regulation, ecosystem functioning, and environmental sustainability, making them important for competitive exams.
Correct Answer:
(A) Carbon captured by oceans and coastal ecosystems
Blue carbon is simply the term for carbon captured by the world's ocean and coastal ecosystems. Sea grasses, mangroves, and salt marshes along our coast "capture and hold" carbon, acting as something called a carbon sink. These coastal systems, though much smaller in size than the planet's forests, sequester this carbon at a much faster rate, and can continue to do so for millions of years.
Ques: 2
The main role of solar radiation is in –
Correct Answer:
(C) Water cycle
The water cycle is driven primarily by the energy from the sun. This solar radiation drives the cycle by evaporating water from the oceans, lakes, rivers and even the soil. It forms water vapour and clouds, where water droplets eventually gain enough mass to fall back to earth. The water cycle is essentially a closed system, meaning that the volume of water that is in the hydrosphere today is the same amount of water that has always been present in the earth system.
Ques: 3
The 'Common Carbon Metric' supported by UNEP, has been developed for
Correct Answer:
(A) Assessing the carbon footprint of building operations around the world
Common carbon metric for measuring energy use and reporting greenhouse gas emissions from building operations. Leading experts from around the world have, through extensive international cooperation, developed a universal method of measuring a building's carbon footprint. The Common Carbon Metric is the calculation used to define measurement, reporting, and verification for GHG emissions associated with the operation of buildings types of particular climate regions. While it is not a building rating tool, it is consistent with methods for assessing the environmental performance of buildings used globally such as the World Business Council for Sustainable Development (WBCSD), World Resources Institute (WRI) GHG Protocol, etc.
Ques: 4
Which of the following is not a function of the tree?
Correct Answer:
(C) Air pollution
Trees contribute to the environment by providing oxygen, improving air quality, climate amelioration, conserving water, preserving soil and supporting wildlife. Hence, they clean the environment and are not the reason behind air pollution. In addition to this, trees on both sides of roads reduce the sound pollution by reducing the intensity of sound by 10 to 15 decibels.
Ques: 5
Consider the following:
1. Photosynthesis 2. Respiration
3. Decay of organic matter 4. Volcanic action
Which of the above add carbon dioxide to the carbon cycle on Earth?
Correct Answer:
(C) 2, 3 and 4
The decay of organic matter, volcanic action, respiration and burning of fossil fuel etc contribute carbon dioxide to the carbon cycle, whereas plants use carbon dioxide in the process of photosynthesis. Thus, plants do not add carbon dioxide to the carbon cycle rather they release oxygen and consume carbon dioxide. Three natural allotropes of elemental carbon are – fullerene, graphite and diamond. Besides, as a compound, it is found as carbon dioxide, carbonate and Hydrogen carbonate.