54.According to IUCN (2004), total number of plant species describe on Earth are around: A. 0.5 million B. 1.5 million C. 1.5 billion D. 0.5 billion
Option B According to the IUCN or International Union for the Conservation of Nature and Natural Resources (2004), which is the world's oldest and largest global environmental organisation, more than 1.5 million different species of plants and animals have been described so far.
