Olympiad Test: Pollution and Calamities - Class 6 MCQ

Explanation:

• (i) Loss of habitat for wildlife:
  When trees are cut down and forests are cleared, animals lose their natural habitats, leading to a decline in biodiversity.

• (ii) Increase in soil erosion:
  Trees and vegetation help anchor the soil in place. When forests are removed, the soil becomes more vulnerable to erosion by wind and water.

• (iii) Decrease in carbon dioxide levels:
  This statement is incorrect. Cutting down trees actually increases carbon dioxide levels in the atmosphere, as trees absorb CO₂ for photosynthesis. Without them, less CO₂ is absorbed.

• (iv) Climate change and global warming:
  Deforestation contributes to climate change and global warming because it reduces the number of trees that can absorb CO₂, a greenhouse gas. Additionally, the process of clearing forests often releases stored carbon into the atmosphere.

Prolonged exposure to excessive noise pollution can lead to various health issues. It may cause headaches, disrupt sleep patterns, and over time, lead to hearing impairments or deafness, impacting the overall well-being of individuals.

Segregating waste into wet and dry components allows for effective recycling and proper disposal methods. This practice helps reduce pollution and encourages recycling initiatives, contributing to a cleaner environment.

The Richter scale, developed by Charles F. Richter in 1935, measures the magnitude of earthquakes based on seismic waves. It is a logarithmic scale, where each whole number increase represents a tenfold increase in the amplitude of the seismic waves.

Continuous drought conditions lead to decreased rainfall and increased evaporation, causing a depletion of water resources like the water table.

Droughts can result from a combination of factors, including a lack of rainfall, prolonged high temperatures, and dry, windy conditions, leading to water scarcity and arid conditions.

Rainwater harvesting involves collecting rainwater, usually from rooftops or other surfaces, and storing it for later use. This method helps in water conservation and provides an additional water source during dry periods.

Seismologists are scientists who study earthquakes, seismic waves, and the behavior of Earth's crust to understand seismic activity and its implications.

Bio-magnification refers to the accumulation of harmful substances such as pesticides, heavy metals, or other toxins in the tissues of organisms at higher trophic levels in a food chain or web.

Severe damage typically begins at a Richter scale reading of 5 or higher. Each whole number increase on the Richter scale indicates a tenfold increase in the amplitude of an earthquake's seismic waves, signifying increased potential for destruction.