Q4. Can you think of a situation where we deliberately want to make a species extinct? How would you justify it? (NCERT Exercise 10, page 227.)
A pathogen that causes a deadly disease is the clearest case. Vaccines and immunisation programmes have already completely eradicated smallpox (NCERT Chapter 7, page 134), and people would justify wiping out such a virus, or a parasite like the malarial parasite, by the lives it would save. The justification is not simple, though: the ethical argument holds that every species has an intrinsic value (page 224), and removing a species can affect others that depend on it, as co-extinctions show (page 223). So any such step should target only organisms that cause great harm, after weighing the effects on the ecosystem (our reasoning).
Q5. What is bioprospecting, and why can it benefit nations rich in biodiversity?
Bioprospecting is exploring molecular, genetic and species-level diversity for products of economic importance. With more resources going into it, nations endowed with rich biodiversity can expect to reap enormous benefits, for example from medicinal plants still waiting to be explored in tropical rain forests (NCERT page 223).
Q6. Define a biodiversity hotspot. Name the three hotspots that cover India’s richest biodiversity regions.
A biodiversity hotspot is a region with very high levels of species richness and a high degree of endemism, species confined to that region and found nowhere else; hotspots are also regions of accelerated habitat loss. India’s are the Western Ghats and Sri Lanka, Indo-Burma, and the Himalaya (NCERT page 224).
Q7. How does NCERT describe endangered or threatened organisms, and which approach does it recommend for them?
Organisms facing a very high risk of extinction in the wild in the near future. When such an organism needs urgent measures to save it from extinction, ex situ (off site) conservation is the desirable approach (NCERT page 224).
Q8. What fraction of the drugs sold in the market worldwide comes from plants, according to NCERT, and how many plant species contribute to traditional medicines?
More than 25 per cent of the drugs sold worldwide are derived from plants, and 25 000 species of plants contribute to the traditional medicines used by native peoples around the world (NCERT page 223).
Q9. What did the Convention on Biological Diversity and the World Summit on Sustainable Development ask of nations?
The Convention on Biological Diversity (the Earth Summit, Rio de Janeiro, 1992) called upon all nations to take appropriate measures for the conservation of biodiversity and the sustainable use of its benefits. At the follow-up World Summit on Sustainable Development (Johannesburg, 2002), 190 countries pledged to achieve by 2010 a significant reduction in the current rate of biodiversity loss at global, regional and local levels (NCERT page 225).