CBSE Class 9 Answered

Lichens are best indicaters of air pollution. Lichen growth and health can assess many air pollutants and the value of these living organisms rather than man-made instruments for assessing sulfur dioxide levels is that they are inexpensive and give quick results. Healthy lichens can be transplanted into areas suspected of being polluted, and then physiological parameters such as respiration and photosynthesis can be monitored to give a rapid indication of pollution levels.

Anaerobic bacteria are poisoned by elemental oxygen.

The full formof IUCN is International Union for Conservation of Nature.

It helps the world find pragmatic solutions to our most pressing environment and development challenges. It supports scientific research, manages field projects all over the world and brings governments, non-government organizations, United Nations agencies, companies and local communities together to develop and implement policy, laws and best practice.

IUCN is the world’s oldest and largest global environmental network - a democratic membership union with more than 1,000 government and NGO member organizations, and almost 11,000 volunteer scientists in more than 160 countries