Q. 1. How are plants and animals important to mankind?
Ans. Human is a herbivore as well carnivore and consumes a substantial number of different plant and animal species. Early humans were dependent upon those plants that produced food. They were also dependent upon herbivores that were capable of relatively easy management. They domesticated animals early in history.
Plants and animals provide meat products and dairy products to feed millions of people.
Q. 2. What is conservation of Bio-diversity?
Ans. Conservation of bio-diversity is a strategy to maintain and evolve species. This will maintain gene pools. It will prove valuable for the future generations.
Q. 3. Trace the history of Bio-diversity. Which region has the highest Bio-diversity?
Ans. Bio-diversity is the result bio-diversity than in any other period. Since the emergence of humans, however, bio-diversity has begun a rapid decline, with one species after another suffering extinction. The number of species, globally vary from 2 million to 100 million, with 10 million being the estimate. Most of the diversity is found in tropical forests.
Q. 4. Explain the role of species in Eco-system.
Ans. (i) Species capture and store energy.
(ii) These produce organic material.
(iii) These help in cycle of water and nutrients.
(iv) These fix atmospheric gases.
Q. 5. What are the causes of Bio-Diversity?
Ans. Weathering is the basis of Bio-diversity input of solar energy and water cause Bio-diversity. The areas which are rich in these inputs are the areas of wide spectrum of Bio-diversity.
Q. 6. Bio-diversity is a system of Constant Evolution. Explain.
Ans. Bio-diversity is the living wealth. It is a result of hundreds of millions of years of evolutionary history. Bio-diversity is not static. It is a system in constant evolution, from a species, as well as from an individual organism point of view. The average half-life of a species is estimated at between one and four million years, and 99% of the species that have ever lived on earth are today extinct. Bio-diversity is not distributed evenly on earth. It is consistently richer in the tropics. As one approaches polar regions one finds larger and larger populations of fewer and fewer species.
Q. 7. Classify different species on the basis of conservation of plants and animals.
Ans. The International Union of Conservation of Nature and Natural Resources (IUCN) has classified the threatened species of plants and animals into three categories for the purpose of their conservation.
1. Endangered Species. It includes those species which are in danger of extinction. The IUCN publishes information about endangered species worldwide as the Red List of threatened species.
2. Vulnerable Species. This includes the species which are likely to be in danger of extinction in near future if the factors threatening to their extinction continue. Survival of these species is not assured as their population has reduced greatly.
3. Rare Species. Population of these species is very small in the world, they are confined to limited areas or thinly scattered over a wider area.
Q. 8. State the four causes of loss of Biodiversity.
Ans. (i) Natural calamities
(iii) Exotic species
(iv) Illegal Hunting.
Q. 9. State two aspects of conservation of species.
Ans. (i) Man should practise environment friendly activities.
(ii) Sustainable development should be aimed at.
(iii) Cooperation of local communities be involved.
Q. 10. What do you know by ‘Mega Diversity Centres’. Name the important mega diversity centres of the world.
Ans. The countries situated in Tropical Regions have a large number of world’s, species diversity.
These are called Mega Diversity Centres.’ There are 12 such countries namely—Mexico, Columbia, Equador, Peru, Brazil, Zaire, Madagasar, China, India, Malaysia, Indonesia and Australia.