Biodiversity and Conservation Class 12 Introduction
Biodiversity and Conservation Class 12:- From macromolecules to the biomes, tremendous diversity is exhibited in our biosphere not only at level of the species but also at various levels of the biological organizations. The term ‘biodiversity’ was popularized by Edward Wilson to describe combined diversity at all the levels. Most significant amongst them are – Genetic diversity, species diversity and the ecological diversity. Biodiversity on the earth is essential for survival of the mankind and its conservation, the need of hour.
Given below are questions on the Biodiversity and Conservation, Class 12 ,along with detailed explanations for reference.
Important Questions for Chapter 15 Biodiversity and Conservation Class 12
Biodiversity and Conservation Class 12 – Very Short Answer Types Questions-
Q.1. What features make the community stable?
A.1.Following characteristics make a community stable, these are-
- Resistance to the infrequent disturbances.
- Lesser variation in the productivity from year to year.
- Impedance to invasions by the alien species.
Q.2. In past, which factor would have caused a mass extinction of the species?
A.2. As per the scientists, following would have triggered mass extinction:
- Temperature fluctuations.
- Meteorite/Asteroid hitting planet.
- Emission of the lethal hydrogen sulphide from sea.
- The outburst of the gamma radiations/supernova/Nova.
- Plate tectonics.
Q.3. Write the reason behind vast diversity in the Indian ecology?
A.3. It can be attributed to geographical diversity in terms of the differing topography such as the rain forests, deserts, coral reefs etc, thereby resulting in the different varieties of the ecosystems with diversity.
Q.4. Write the name of an artificial ecosystem with the high productivity.
A.4. The name of the artificial ecosystem- Agricultural field of the wheat or the paddy.
Q.5. In IUCN Red List(2004), what does the ‘Red’ represent?
A.5. It is used to refer to taxa with were the highest risk of the extinction.
Q.6. How can prevailing rate of the species extinction be declined by 30% solely through the protection of the biodiversity hotspots?
A.6. Hotspots are the species-rich, precisely those under the human threat hence protecting them can significantly decrease rate of the extinction. They can be preserved as the sanctuaries and the national parks.
Q.7. Write the difference between the endemic and the exotic species.
A.7. The Exotic species are derived into a geographical area from the another geographical area whereas the Endemic species are native species restricted to a particular geographical area.
Q.8. Write the difference between the species diversity and the ecological diversity.
A.8. The distribution and the number of the species in an area are referred to as species diversity whereas the ecological diversity describes diversity at ecosystem level.
Q.9. Write the significance of the genetic variation in Rauwolfia vomitoria plant?
A.9. This plant is a source of the drug reserpine which serves as a tranquillizer. Its genetic variation can be in terms of the concentration of the resperin and the potency produced by plant.
Q.10. Explain about the Red Data Book.
A.10. It is a collection of the records or the data of the species with risk of the extinction maintained by IUCN.
Q.11. What do you mean by a gene pool?
A.11. In a breeding population, it refers to sum total of all genes of every individual.
Biodiversity and Conservation Class 12 Quiz
Q.12. Write about the ‘Frugivorous’?
A.12. It is used to refer to the fruit-eating animals.
Q.13. Expand the term IUCN.
A.13. The full form of IUCN is
International Union for the Conservation of Nature and Natural Resources.
Q.14. What do you mean by –
A.14. a) It is used to illustrate process of the discovery and the commercialization of the new products based on the biological resources.
b) Endemism attributes to species that are unique to a specific region only. They are not found anywhere else except to that region.
Q.15. Write the common feature between species A and B.
A.15. Both plants are the angiospermic flowering plants.
Q.16. Write common feature between the species A and B.
A.16. Both the animals are preserved in their natural habitats.
Q.17. What do you mean by biodiversity hotspot?
A.17. A biodiversity hotspot is a biogeographic region with a large amount of the biodiversity that is threatened by the human habitation.
Biodiversity and Conservation Class 12 – Short Answer Types Questions-
Q.1. State how current occurrence of the species extinction is different from earlier mass extinction.
A.1. Species extinction in earlier times occurred due to the natural calamities such as volcanic eruptions, landslides, flood etc, while in present times, the cause of the species extinction is the human beings activities.
Q.2. Which of following according to you is major cause for the loss of the biodiversity amongst four main causes of the loss of biodiversity ( Habitat loss and fragmentation, alien species invasion, over-exploitation and co-extinctions)? Justify your answer.
A.2. Habitat loss and the fragmentation. As it is caused by the clearing and the over-exploitation of the forest land for the urbanization and the industrialization purposes. Overpopulation has destroyed the forests and the burdened forest resources. Larger habitats are split into the smaller fragments causing the birds and the mammals to migrate in quest of the larger territories thereby resulting in population declination.
Q.3. How can loss of one species lead to extinction of the another?
A.3. It can be explained via co-extinction, where the extinction of two mutually interrelated species takes place. For instance, extinction of the host fish causes extinction of all the parasites located on it.
Q.4. Can the diversity and the productivity of a natural community be constant for over a hundred years?
A.4. No, it is not possible as natural habitat is never maintained in real, resources cannot be available in abundance always and the environmental conditions for the survival keeps fluctuating.
Q.5. Why is there a greater biodiversity in the subtropical/tropical regions than in the temperate regions?
A.5. It is because these regions are not disturbed due to the lesser variations in the climatic conditions. This is why the species had a longer evolutionary time for the diversity. The environment in the temperate regions is more seasonal and unpredictable, hence lesser species diversity.
Q.6. For assessment of the biodiversity in the bacteria, why are the conventional methods unsuitable?
A.6. It is because the bacteria cannot be cultured in the normal conditions which makes it difficult to study their biochemical and the morphological characteristics. Hence these are clubbed with a few more characteristics to assess biodiversity of the bacteria.
Biodiversity and Conservation Class 12 study Materials
Q.7. Write the factors that determines a species as threatened?
A.7. Following criteria needs to be used in categorizing a species as threatened:
- Declination in number of the species at a distressing rate.
- Destruction and the modification of their habitat
- Increasing the activities of the poachers.
Q.8. In comparison to the other animal groups, why are the amphibians more vulnerable to the extinction?
A.8. It is because of following:
- Habitat fragmentation.
- Habitat Destruction or the Modification.
- Large scale climate change.
Q.9. How do the scientists estimate total number of the species on earth?
A.9. Through the two methods:
- Estimation rate of the discovery of the new species.
- Statistical association of the tropical and the temperate species richness of exhaustively studied assemblages of the insects. The ratio is then deduced with current species to predict total estimate.
Q.10. State two ways through which the humans are benefitted from the biodiversity.
A.10. We derive economic benefits from diversity of the entities, such as the –
- Food, fibre, and firewood.
- Industrial products, and the construction material.
- Medicinal products from th the plants.
- Pure oxygen, flood and soil erosion control, and the natural pollinators.
- Recycling of the wastes by the microbes.
- Nutrient restoration.
Q.11. What do you mean by endangered species. Give an example for the endangered plant and the animal species.
A.11. It is a population of the species at brink of the extinction.
Endangered animal is- Siberian Tiger, Endangered plant is-Venus fly trap.
Q.12. Write about the sacred groves. What is their role in conservation of the biodiversity?
A.12. They are the sacred tracts which are of utmost importance to the local communities. They are devoted to the ancestral spirits and the local deities and are guarded by the local communities through the taboos and the social traditions which includes the ecological and the spiritual values. They are rich in the biodiversity nurturing rare plant and the animal species and are found in the Aravalli hills, Meghalaya, western Ghats etc.
Q.13. Is the solar energy more available at tropics? Justify your answer.
A.13. Yes, it is true. It is because of following reasons:
- The rays of sun possess less atmosphere to pass through hence lesser energy is lost in reflection and absorption by atmosphere.
- The rays of sun are more concentrated.
- Presence of the dense vegetation causes more absorption of the radiations in tropical rainforests.
Biodiversity and Conservation Class 12 – Long Answer Types Questions-
Q.1. Explain how the species diversity of an area is reduced by invasion of the alien species.
A.1. When the alien species acquaint a particular habitat either purposely or inadvertently, some of these species resort to the invasion thereby causing the declination or the extinction of the native species. For instance – Lantana and water hyacinth have turned invasive, Invasion of the Nile perch, a large predator fish, into the Lake Victoria in the East Africa led to an extinction of an ecologically unique collection of more than 200 species of the Cichlid fish in lake. As Cichlid fish became extinct due to a lack of food, predatory Nile perch died too.
Q.2. How can loss of the biodiversity be prevented?
A.2. The occurrence of different types of the habitat, species, ecosystem, gene pool, a gene in a particular area in biodiversity. It can be conserved with the various conservational strategies and the management of the abiotic and the biotic resources.
Listed below are a few conservational strategies, these are-
- Natural conservation or the protection of the useful plants and the animals in their natural habitats.
- Conserving crucial habitats like the breeding and the feeding areas, facilitating growth and the multiplication of the endangered species.
- Regulation or the banning hunting activities.
- Through the bilateral or the multilateral agreements, habitats of the migratory entities should be conserved.
- Spreading the awareness of the significance of the conservation of the biodiversity.
- Avoiding the over-exploitation of the natural resources.
Q.3. Besides relationship used by Paul Ehrlich, can you arrive at a scientific explanation to explain direct association between the stability and the diversity of an ecosystem?
A.3. It could be as follows:
Consider a scenario where the diverse species are growing, plants nurture a diversity of the species on which an assemblage of the insect species are dependent for their food requirements. The dependence severely affects relying insect species due to the unavailability of the food, when this particular plant species die. Additionally, if plant was a nitrogen fixer, death of plant would indicate no restoration of the soil nutrients with the nitrogen. This would also affects growth of plants. If this is followed and occurs regularly, it would put forward a negative impact on whole ecosystem.
Q.4. Write about the ecosystem service. Write any four ecosystem services rendered by natural ecosystem. Are you in the support or against imposing a charge on service given by ecosystem?
A.4. Ecosystem services are products of the ecosystem processes. The major services of the ecological services are forests. Some of their services are as follows –
- Water and the air purification.
- Droughts and the flood alleviation.
- Cycling nutrients.
- Fertile soil generation.
- Rendering the wildlife habitat.
- Promoting the biodiversity.
- Crop pollination.
- Provisions of a storage site for the carbon.
- Facilitating with the cultural, the aesthetic and the spiritual values.
No, not in the favour of levying a charge. However, it is necessary to understand what nature is offering for free. Misusing or the overusing resources may impose a heavy cost.
Q.5. Why does the diversity amongst the species decline as we move away from equator?
A.5. It is because a decline in the temperature causes state to become severe. There is a dip in intensity and the amount of the solar radiations and also a decrease in vegetation is observed. Availability of the resources is less to support assemblage of the species. Harsh conditions make adaptation and the survival of the species difficult, which results in a decrease of the biodiversity as we approach poles.
Q.6. Write about the ‘rivet popper hypothesis’ which was given by by Paul Ehrlich.
A.6. He suggested hypothesis to understand benefaction of the species richness which he arrived at by comparing each species with rivet seen in aeroplane body. It demonstrates that ecosystem to be an aeroplane and species, rivets holding together all parts. If each passenger began to take rivets home (depicting species extinction), it may hardly affect safety of flight initially (representing the stable functioning of ecosystem), eventually, plane becomes fragile and crash, implying species become endangered and ultimately extinct.
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