Extra Questions for Class 12 Biology Chapter 15 Biodiversity and Conservation
Q.1. Define biodiversity.
Ans. The occurrence of different types of genes, gene pools, species, habitats and ecosystems in a particular place and various parts of earth is called biodiversity.
Q.2. What is mass extinction?
Ans. Due to natural calamities like volcanic eruptions, prolonged drought, heavy rains, earthquakes, asteroid collision, etc., a large number of species become extinct at the same time which is called mass extinction.
Q.3. What is Red Data Book?
Ans. The Red Data Book is a compilation of data on species threatened with extinction and is maintained by IUCN.
Q.4. What are seed banks?
Ans. The collection of seeds of many different genetic strains of commercially important plants, that are kept viable for longer periods in place are called seed banks.
Q.5. India has more than 50,000 strains of rice. Mention the level of biodiversity it represents.
Ans. 50,000 strains of rice represent genetic biodiversity.
Q.6. What is the expanded form of IUCN?
Ans. International Union for Conservation of Nature and Natural Resources.
Q.7. What is genetic diversity?
Ans. It is the measure of variation in genetic information contained in the organisms.
Q.8. Write the importance of cryopreservation in conservation of biodiversity.
Ans. By cryopreservation, the reproductive parts of rare species can be preserved.
Q.9. Name the type of biodiversity represented by the following:
(i) 50,000 different strains of rice in India
(ii) Estuaries and alpine meadows in India.
Ans. (i) Genetic diversity
(ii) Ecological diversity
Q.10. What are Ramsar sites?
Ans. Ramsar sites are conserved wetlands which are of international importance.
Q.11. Name the type of biodiversity represented by the following:
(i) 1000 varieties of mangoes in India.
(ii) Variations in terms of potency and concentration of reserpine in Rauwolfia vomitoria
growing in different regions of Himalayas.
Ans. (i) Genetic diversity
(ii) Genetic diversity
Q.12. Name the unlabelled areas ‘a’ and ‘b’ of the pie chart representing biodiversity of vertebrates showing the proportionate number of species of major taxa
Ans. a → Fishes;
b → Amphibians.
Q.13. About 200 species of Cichlid fish became extinct when a particular fish was introduced in Lake Victoria of Africa. Name the invasive fish.
Ans. Nile perch.
Q.14. What is meant by alien species?
Ans. Non-native powerful species which invade a new area are known as alien species.
Q. 15. According to David Tilman, greater the diversity greater is the primary productivity. Can you think of a very low diversity man-made ecosystem that has high productivity.
Ans. Agricultural fields like wheat field or paddy field which are also examples of monoculture practices.
Q.16. Name the alien fish species which is posing a threat to the indigenous catfishes in our rivers.
Ans. Clarias gariepinus (African catfish)
Q.17. What is the difference between endemic and exotic species? [NCERT Exemplar] [HOTS]
Ans. Endemic species are native species restricted to a particular geographical region. Exotic species are species which are introduced from other geographical regions into an area.
Q.18. Name the unlabelled areas ‘a’ and ‘b’ of the pie chart (given alongside) representing the global biodiversity of invertebrates showing their proportionate number of species of major taxa.
Ans. a → Insects;
b → Molluscs
Q.19. Western Ghats have a greater amphibian diversity than the Eastern Ghats. What do you infer from the above two statements?
Ans. It can be inferred that Western Ghats have a greater species diversity.
Q.20. Identify ‘a’ and ‘b’ in the figure given below representing proportionate number of major vertebrate taxa.
Ans. a → Mammals
b → Amphibians
Q.21. Why is genetic variation important in the plant Rauwolfia vomitoria? [NCERT Exemplar]
Ans. Genetic variation affects the variation in potency and concentration of the drug reserpine in the medicinal plant Rauwolfia.
Q.22. Name any two sanctuaries in India.
Ans. Keoladeo Ghana bird sanctuary, Bharatpur (Rajasthan) and Periyar sanctuary (Kerala).