NEET Biology Biodiversity and Conservation Important Questions Set 01

These Class 12 NEET Biology important questions on Biodiversity and Conservation give 45 questions with step-by-step answers, arranged as very short, short and long answer types, as asked in school and board examinations. They help NEET aspirants revise the definitions, structures, differences and key terms of the chapter.

Very Short Answer Type Questions

Question 1. Who coined the term biodiversity?
Answer: Term biodiversity was coined by Edward Wilson.

Question 2. How much area of earth's land area is covered by hot spots?
Answer: Less than 2 percent of land area.

Question 3. What are seed banks?
Answer: Seeds of different genetic strains of commercially important plants are kept for long periods in seed banks.

Question 4. Name two methods of ex-situ conservation.
Answer: (i) Botanical gardens
(ii) Zoological parks

Question 5. How many biosphere reserves are there in India?
Answer: 14 biosphere reserves.

Question 6. What are alien species?
Answer: Species introduced in an area where they are not native are alien species.

Question 7. What is the most important cause of biodiversity loss?
Answer: Habitat loss and fragmentation.

Question 8. What is unique about the 'Sixth extinction'?
Answer: It is 100 to 1000 times faster than pre-human times.

Question 9. Which Indian hotspots extend into other countries?
Answer: (i) Western Ghats and Sri Lanka
(ii) Indo-Burma

Question 10. Name the plant which produces reserpine.
Answer: Rauwolfia vomitoria.

Short Answer Type Questions

Question 11. How cryopreservation helps conserve biodiversity?
Answer: Cryopreservation is used to preserve gametes of threatened species in viable and fertile conditions for long periods.

Question 12. List the major factors which lead to loss of biodiversity.
Answer: (i) Habitat loss and fragmentation
(ii) Over-exploitation
(iii) Alien-species invasions
(iv) Co-extinctions.

Question 13. What are the aesthetic benefits of biodiversity?
Answer: (i) Pleasures of walking through thick woods
(ii) Watching spring flowers in full bloom
(iii) Waking upto a bulbul's song in the morning.

Question 14. Which part of the world is called the 'lungs of the planet'? What is the cause of its degradation?
Answer: (i) Amazon rain forests are considered the lungs of the planet.
(ii) The cause of its degradation are :
(a) They are being cut and cleared for cultivating soya beans.
(b) For conversion to grasslands for raising beef cattle.

Question 15. Name four recent extinctions of animals.
Answer: (i) Steller's sea cow (Russia)
(ii) Dodo (Mauritius)
(iii) Thylacine (Australia)
(iv) Quagga (Africa)

Question 16. Mention the global species diversity of ants, beetles, fishes and orchids.
Answer: There are more than 20000 species of ants, 300000 species of beetles, 28000 species of fishes and nearly 20,000 species of orchids.

Question 17. What is ecological diversity?
Answer: Diversity at the level of ecosystem is called ecological diversity, e.g. India with its deserts, rain forests, mangroves, coral reefs, wetlands, estuaries and alpine meadows has greater ecosystem diversity than a Scandinavian country like Norway.

Question 18. What are the two major approaches for the conservation of biodiversity?
Answer: (i) In-situ strategies like biosphere reserves and national parks.
(ii) Ex-situ strategies like botanical gardens and seed banks.

Question 19. Explain the effect of habitat fragmentation on diversity?
Answer: When large habitats are broken up into small fragments due to various human activities, mammals and birds requiring large territories and certain animals with migratory habits are badly affected, leading to population declines.

Question 20. Why there is lesser biodiversity at the temperate climate than tropics?
Answer: Speciation is a function of time. Tropical latitudes have remained relatively undisturbed for millions of years and had a long evolutionary time for species diversifications. Tropical environments unlike temperate ones, are less seasonal. Such constant environments promote niche specialisation and lead to greater species diversity. There is more solar energy available in tropics, which contributes higher productivitiy.

Question 21. How zoological parks and national parks differ with regard to conservation strategy?

Answer:

Zoological parks National Parks
(1) It is an ex-situ conservation (1) It is an in-situ mode of conservation. strategy.
(2) In this method, threatened animals (2) In this method ecologically unique and

Question 22. Biologists are not sure about how many prokaryotic species there might be? Expain it.
Answer: Any figures for prokaryotes are not given because :
(i) Conventional taxonomic methods are not suitable for identifying microbial species.
(ii) Many species cannot be cultured under laboratory conditions.
(iii) Biochemical or molecular criteria for delineating species for this group will put their diversity into millions.

Question 23. What changes in biodiversity can be brought about by the fragmentation of habitat?
Answer: When large habitats are broken up into small fragments due to various human activities, mammals and birds requiring large territories and certain animals with migratory habits are badly affected, leading to population declines.

Question 24. Comment on the scenario of species facing threat of extinction.
Answer: (i) Presently more than 15,500 species world wide are facing the threat of extinction.
(ii) 12% of all bird species, 23% of all mammal species, 32% of all amphibian species and 31% of all gymnosperm species in the world face the threat of extinction.
(iii) Some groups like amphibians appear to be more vulnerable to extinction.

Question 25. Represent diagrammatically the global biodiversity of different groups of invertebrates.

Answer:

Other animal groups Crustaceans Molluscs

Insects

Question 26. Diagrammatically represent the proportionate number of species of major taxa of plants.

Answer:

Mosses Ferns and allies

Question 27. Diagrammatically represent the proportionate number of major taxa of vertebrates as globally.

Answer:

Fishes Mammals

Birds

Reptiles

Amphibians

Question 28. Name two sacred groves of Meghalaya. How they are very important in conserving biodiversity?

Answer:

(i) The two sacred groves in Meghalaya are:
(a) Khasi hills

(b) Jaintia hills

(ii) In Meghalaya, the sacred groves are the last refuges for a large number of rare and threatened plants.

Question 29. What is unique about 'biodiversity hotspots'? What is the total number of such hotspots in world?

Answer:

(i) Uniqueness of biodiversity hot spots:
(a) They have very high levels of species richness.

(b) And high degree of endemism.

(ii) Total number of biodiversity hotspots in the world is 34.

Question 30. Mention three consequences of loss of biodiversity in a region.

Answer:

Loss of biodiversity in a region may lead to
(i) Decline in plant production.

(ii) Lowered resistance to environmental perturbations like drought.

(iii) Increased variability in ecosystem processes like plant productivity, water use, disease cycles etc.

Long Answer Type Questions

Question 31. (a) Why the indigenous catfishes in our rivers are under threat.
(b) Give two examples of co-extinctions.

Answer:

(a) (i) The recent illegal introduction of the African catfish Clarias gariepinus for aquaculture purposes is posing a threat to indigenous catfishes in our rivers.

(ii) It is an example of alien species invasion.

(b) Two examples of co-extinctions:

(i) When a host fish species becomes extinct, its unique assemblage of parasites also meets the same fate.

(ii) A co-evolved plant-pollinator mutualism where extinction of one invariably leads to the extinction of the other.

Question 32. Give an account of the biodiversity in India.
Answer: (i) India is one of the 12 mega diversity countries of the world.
(ii) It has only 2.4 percent of the world's land area, its share of the global species diversity is 8.1%.
(iii) Nearly 45,000 species of plants and twice as many of animals have been recorded from India.
(iv) If we accept May's global estimates, only 22% of the total species have been recorded so far. Applying this proportion to India's diversity figures, there are probably more than 1,00,000 plant species and more than 3,00,000 animal species to be described and discovered.

Question 33. (a) Who proposed River-Popper hypothesis? Explain the same.
(b) Analyse the species-area relationship over large continents.
Answer: (a) (i) Rivet-popper hypothesis was proposed by Stanford ecologist Paul Ehrlich. It explains importance of species richness through an analogy.
(ii) In an airplane (ecosystem) all parts are joined together using thousands of rivets (species).
(iii) If every passenger travelling in it starts popping a rivet to take home (causing a species to become extinct), it may not affect flight safety (proper functioning of the ecosystem) initially.
(iv) But as more and more rivets are removed the plane becomes dangerously weak over a period of time.
(v) Further more, which rivet is removed may also be critical. Loss of rivets on the wings (key species that drive major ecosystem functions) is obviously a more serious threat to flight safety than loss of a few rivets on the seats or windows inside the plane.
(b) If we analyse the species-area relationships among very large areas like the entire continents we will find Z values in the range of 0.6 to 1.2. i.e., the slope of the line is much steepe. e.g. for frugivorous (fruit-eating) birds and mammals in tropical forests of the different continents, the slope is 1.15.

Question 34. (a) Mention the characteristics of a stable community.
(b) Comment on the findings of IUCN Red List (2004).
Answer: (a) Characteristics of stable community:
(i) It should not show too much variation in productivity from year to year.
(ii) It must be either resistant or resilient to occasional disturbances both natural or man-made.
(iii) It must also be resistant to invasions by alien species.
(b) The IUCN Red List 2004 documents the extinction of 784 species in the last 500 years. It includes
(i) 338 – Vertebrates
(ii) 359 – Invertebrates
(iii) 87 – Plants

Question 35. (a) What does the term heterogeneity means? Mention any two factors which pose threat to biodiversity.
(b) Sometimes introduction of alien species causes decline or extinction of indigenous species. Explain the statement with any two examples.
Answer: (a) (i) The term heterogeneity or biodiversity is used to describe the combined diversity at all the levels of biological organisation ranging from macromolecules within cell to biomes. The term was popularised by Edward Wilson.
(ii) Two important factors which pose threat to biodiversity are:
(1) Habitat loss and fragmentation
(2) Over-exploitation
(b) (i) The Nile perch introduced into Lake Victoria in East Africa led eventually to the extinction of an ecologically unique assemblage of more than 200 species of cichlid fish in the lake.
(ii) Carrot grass (Parthenium), Lantana and water hyacinth (Eicchornia) cause environmental damage and posed threat to our native species.

Question 36. Colombia near the equator has nearly 1400 species of birds, while New York at 41°N has 105 species and Green-land at 71°N has only 56 species, but India has more than 1200 species of birds. What does this indicate? What are the reasons given for such a distribution?
Answer: This indicates that:
(i) Species diversity decreases from equator towards the poles.
(ii) With very few exceptions, tropics (latitudinal range of 23.5°N to 23.5°S) harbour more species of plants and animals or biodiversity than temperate or polar areas. Reasons:
(i) Unlike temperate regions subjected to frequent glaciations in the past, tropical latitudes have remained relatively undisturbed for millions of years and thus, had a long evolutionary time for species diversification.
(ii) Tropical environments unlike temperate ones are less seasonal, relatively more constant and predictable. Such environments promote niche specialisation and lead to a greater species diversity.
(iii) There is more solar energy available at the tropics, which contributes to higher productivity, this in turn might contribute indirectly to greater diversity.

Question 37. Which region of the world has the greatest biodiversity on Earth. Analyse its diversity? What are the major causes of its degradation?
Answer: (i) The largely tropical Amazonian rain forest in South America has the greatest biodiversity on Earth.
(ii) It is home to
(a) More than 40000 species of plants
(b) 3000 species of fishes
(c) 1,300 species of birds
(d) 427 of mammals
(e) 427 of amphibians
(f) 378 of reptiles and
(g) More than 1,25,000 invertebrates
(iii) Scientists estimate that in these rain forests there might be at least two million insect species waiting to be discovered and named.
(iv) The Amazon rain forest is so huge that it is called the 'lungs of the planet'.
(v) These forests are being cut and cleared for
(a) Cultivating soya beans OR
(b) For conversion to glasslands for raising beef cattle.

Question 38. (a) How biodiversity hotspot could reduce mass extinctions?
(b) Discuss methods adopted in India to conserve biodiversity.
Answer: (a) Although all the 34 biodiversity hotspots put together cover less than 2 percent of the earth's land area, the number of species they collectively harbour is extremely high and strict protection of these hotspots could reduce the ongoing mass extinctions by almost 30 percent.
(b) (i) In India, ecologically unique and biodiversity rich regions are legally protected as biosphere reserves, national parks and sanctuaries.
(ii) India now has 14 biosphere reserves, 90 national parks and 448 wildlife sanctuaries.
(iii) In India, tracts of forest were set aside, and all the trees and wildlife within were venerated and given total protection. Such sacred groves are the last refuges for a large number of rare and threatened plants.

Question 39. (a) When and where was the World Summit on sustainable development held? How many countries signed the convention? What was the objective?
(b) Ecologically hot spots are determined by many factors write down it.
Answer: (a) (i) The World Summit on sustainable development was held in Johannesburg, South Africa in 2002.
(ii) 190 countries pledged their commitment to achieve by 2010, a significant reduction in the current rate of biodiversity loss at global, regional and local levels.
(b) (i) Number of species
(ii) Degree of endemism
(iii) Degree of threat to habitat due to its degradation and fragmentation.

Question 40. (a) What is the difference between a sanctuary and a wildlife safari?
(b) What we owe to millions of species with whom we share this planet?

Answer:

(a) Sanctuary Wildlife safari
(1) It is an in-situ method of (1) It is an ex-situ conservation strategy. conservation.
(2) We save the entire forest to (2) Threatened animals are taken out from conserve the tiger. their natural habitat and placed in special setting and given care.

(b) (i) Philosophically or spiritually we realise that every species has an intrinsic value, even if it may not be of current or any economic value to us.
(ii) So, we have a moral duty to care for their well-being and pass on our biological legacy in good order to future generations.

Question 41. (a) What is the difference between genetic diversity and species diversity? Explain with examples.
(b) Which of the two countries India or Norway has more ecological diversity and why?

Answer:

(a) Genetic diversity Species diversity

(1) Diversity at the genetic level in a (1) Diversity at the level of species. single species over its distributional range.
(2) e.g., genetic variation shown by the (2) e.g., western Ghats have a greater

(b) (i) India with its deserts, rain forests, mangroves, coral reefs, wetlands, estuaries and alpine meadows has a greater ecosystem diversity than a Scandinavian country like Norway.

(ii) Therefore, ecological diversity is more in India because of the occurrence of a large number of ecosystems.

Question 42. (a) When and where was the Earth Summit held? What was its objective?
(b) What is mass extinction? How many have taken place on our planet? Which extinction is going on presently?

Answer:

(a) (i) The Earth Summit was held in Rio de Janerio in 1992.

(ii) Its objectives were

(a) Conservation of biodiversity.

(b) Sustainable utilisation of benefits from biodiversity.

(b) (i) Large scale loss of species like the one we are currently witnessing is called mass extinction.

(ii) During the long period since the origin and diversification of life on Earth there were five episodes of mass extinction of species.

(iii) The sixth mass extinction is presently in progress.

Question 43. (a) What percentage of drugs sold in market are derived from plants?
(b) How many plant species contribute to traditional medicine?
(c) What is bio-prospecting?
(d) Which countries will reap benefits from bio-prospecting?

Answer:

(a) More than 25 percent of the drugs currently sold in the market worldwide are derived from plants.

(b) 25000 species of plants contribute to the traditional medicines used by native peoples around the world.

(c) Exploring molecular, genetic and species level diversity for products of economic importance is called bio- prospecting.

(d) Nations endowed with rich biodiversity can expect to reap enormous benefits from bioprospecting.

Question 44. (a) What percentage of oxygen is produced by Amazon forest in Earth's atmosphere?
(b) Name some important pollinators.
(c) What type of pleasure is derived by walking through thick woods?
(d) What services plants give us by pollination?
Answer: (a) Amazon forest is estimated to produce through photosynthesis, 20% of the total oxygen in the earth's atmosphere.
(b) Bees, bumblebees, birds and bats are important pollinators.
(c) Aesthetic pleasures.
(d) Plants give us fruits and seeds only after pollination.

Question 45. (a) If an animal or plant is endangered or threatened and needs urgent measures to save it from extinction, what type of conservation approach is desirable? Give some examples of this type of approach.
(b) What idea sacred groves give about our culture? Give some examples.
Answer: (a) Urgent conservation approach is ex-situ (off site). e.g. Zoological parks Botanical gardens Wildlife safari parks Cryopreservation Seed banks
(b) (i) India has a history of religious and cultural traditions that emphasised protection of nature.
(ii) In many cultures, tracts of forests were set aside, and all trees and wildlife within were venerated and given total protection.
(iii) Such sacred groves are found in
(a) Khasi and Jaintia hills of Meghalaya,
(b) Aravalli hills of Rajasthan
(c) Western Ghat regions of Karnataka and Maharashtra
(d) Sarguja, Chanda and Bastar areas of Madhya Pradesh.