Biodiversity
Short Questions and Answers
One mark questions with answers
1. The major reason for extinction of species is
(a) forest fire
(b) hunting
(c) habitat destruction
(d) their use for food
Answer: (c) habitat destruction
2. Threatened species often include
(a) endangered species
(b) vulnerable species
(c) rare species
(d) all of the above
Answer: (d) all of the above
3. Species which occur in small populations and are restricted to only certain geographical areas are placed under the category of
(a) endangered species
(b) vulnerable species
(c) rare species
(d) all of these
Answer: (c) rare species
4. Man and the Biosphere programme (MAB) was launched by
(a) Government of India
(b) IUCN
(c) UNESCO
(d) WWF
Answer: (c) UNESCO
5. In the context of conservation WWF stands for
(a) World Wildlife Federation
(b) World Wildlife Forum
(c) World Wildlife Fund
(d) none
Answer: (c) World Wildlife Fund
6. Which one of the following biosphere reserve is located in Uttarakhand?
(a) Valley of flowers
(b) Sundarbans
(c) Kanha
(d) Kaziranga
Answer: (a) Valley of flowers
7. Bulk of our forests are composed of
(a) temperate deciduous forest
(b) tropical dry deciduous forest
(c) tropical evergreen forest
(d) tropical thorn forest
8. Van Mahotsav is practiced for
(a) forest cutting
(b) forest planting
(c) forest destruction
(d) none of the above
Answer: (b) forest planting
9. Which of the following groups of animals has the highest number of endangered species?
(a) mammals
(b) fishes
(c) reptiles
(d) birds
Answer: (c) reptiles
10. Species mentioned in the Red Data Book are
(a) threatened
(b) endangered
(c) vulnerable
(d) all of the above
Answer: (d) all of the above
11. Hotspots of biodiversity are areas with
(a) little biodiversity
(b) maximum biodiversity
(c) maximum conservation
(d) both b and c
Answer: (b) maximum biodiversity
12. The maximum number of National Parks are located in
(a) Karnataka
(b) Madhya Pradesh
(c) Tamil Nadu
(d) Maharashtra
Answer: (b) Madhya Pradesh
13. If at higher altitudes, birds become rare, plants likely to disappear are
(a) Pine
(b) Orchid
(c) Oak
(d) Rhododendrons
Answer: (d) Rhododendrons
14. Rare species are not
(a) endangered
(b) vulnerable
(c) found in small number
(d) found in large number
Answer: (d) found in large number
15. In the core area of biosphere reserves
(a) only humans are not allowed to stay
(b) only wild species exist
(c) both humans and wild life coexist
(d) limited human activities permitted
Answer: (b) only wild species exist
Two marks questions with answers
1.Name the three important components of biodiversity.
Answer: The three components or levels of biodiversity or genetic diversity, species diversity and ecological diversity. Ecological diversity has again 3 components alpha diversity (within community diversity), beta diversity (between community diversity) and gamma diversity (regional diversity).
2. What is species diversity?
Answer: It refers to the variety of species within a region. It leads to the evolution of new species. Such a diversity could be measured on the basis of number of species in a region. Simplest measures of species diversity is species richness (i.e., the number of species per unit area). A more relevant measure of species diversity takes into account species evenness. It reveals the relative abundance of a species as well as the actual number of different species. An area with almost the same number of all the present species show greater evenness. On the contrary a community with few dominant species and a number of inconspicuous species will have a low species evenness.
3. Differentiate between genetic diversity and species diversity.
Answer: Genetic diversity is trait of the organisms while species diversity is trait of the biotic community. Genetic diversity represents the variety of genetic information present in the organisms. Species diversity includes variety of species and their abundance found within a region. Genetic diversity is important for adaptation to environment and changes occurring in it while species diversity influences the stability of ecosystem.
4. What is the significance of slope of regression in species area relationship?
Answer: Slope of regression or regression coefficient of species area relationship indicates that species richness decreases with decrease in area. Ecologists have found that regression coefficient is 0.1 to 0.2 regardless of the taxonomic group or the region.
5. How do ecologists estimate the total number of species present in the world?
Answer: There are two methods to estimate the number of species:
(1) Rate of discovery of new species
(2) Determination of species richness of an exhaustively studied group of insects in tropics as compared to temperate areas. As organisms have been studied more thoroughly in temperate areas, the data is extrapolated for other groups. Estimates are similarly made for other areas.
Three marks questions with answers
1. Give three hypothesis for explaining why topics show greatest level of species richness.
Answer: The three hypothesis to species richness in tropics are
(1) No catastrophes: Glaciations and other catastrophes have occurred repeatedly in temperate areas causing large-scale destruction of organisms. No such catastrophes have taken place in tropics. The organisms continue to flourish and evolve in tropics.
(2) Non seasonal environment: Tropics have non seasonal, nearly uniform environment. It promotes niche specialisation and increased species diversity.
(3) Solar energy: More solar energy is available in tropics as compared to other parts of the world. This enhances productivity. Higher productivity provides resources for higher number of organisms.
2. What are endemic species?
Answer: Plant and animal species confined to an area are termed as endemic species. Endemism of Indian biodiversity is significant. About 4,900 species of flowering plants are endemic to the country. These are distributed over 141 genera belonging to 47 families. Amongst animals, 62% of the known amphibians and nearly 50% of the lizards found in India are endemic.
Areas that have great biodiversity and high level of endemism and are under immediate threat of habitat destruction are termed as hotspots. Thus the two important criteria determining hotspots are the number of endemic species and the degree of threat to the habitat. So far 25 hotspots have been identified in the world. These together encompass 44% of the world’s plant species, 28% of the bird species, 30% of the animal species, 38% of the reptile species and 54% of the amphibian species.
Of the 25 hot spots, two of them (i.e., Western Ghats and Eastern Himalayas) are in India. The Western Ghats lying parallel to the Western coast of India are the home for 1600 endemic species of flowering plants and amphibians. About 8500 endemic species of flowering plants occur in the Eastern Himalayas. Nearly 50% of the lizards found in India are endemic, with a large number being found in Western Ghats.
3. What are hotspots of biodiversity?
Answer: Hot spots are area that are extremely rich in species, have high endemism and are under constant threat. Of the estimated 5.50 million species of biodata, only 1.7 million have been described till date and the distribution is highly uneven. About 7% of world’s total land area is home to half of the world’s species, with tropics alone accounting for 5 millions. Thus the tropical forests are very important as they harbour at least 50% and perhaps more of world’s biodiversity.
Norman Myers developed the concept of hotspots in 1988 to designate priority areas for in situ conservation. 25 terrestrial hot spots for conservation of biodiversity have been identified worldwide.
4. What do you understand by ecosystem diversity?
Answer: It refers to the diversity of ecosystems and habitats. A wide variety in physical features and climatic situations have resulted in a diversity of ecological habitats like forests, grasslands, wetlands, coastal and marine ecosystems, and desert ecosystems. These ecosystems harbour and sustain the immense biodiversity.
Alpha diversity (i.e within community diversity) refers to the diversity of organisms sharing the same community or habitat.
Beta diversity is the rate of turnover or replacement of species which moving from one habitat to another within a given geographical area. For instance, the difference in species composition between a coral reef and the adjoining intertidal zone would be termed as beta diversity.
Gamma diversity is used for the rate of turnover or replacement of species between similar habitats in different geographical areas. For example the differences in species composition between the coral reef in the Gulf of Kutch and in Andaman Islands.
5. What are sacred groves? What is their role in conservation?
Answer: Sacred groves are patches of forests around the places of worship where the use of axe and sickle are not allowed by the worshippers. In Kumaon area, temples are generally surrounded by Deodar groves. In Meghalaya forest and hills are preserved on similar ground. Sacred forests also occur in Karnataka, Maharashtra, Kerala and other parts.
Role in conservation: Sacred groves have been free from all types of exploitation. They, therefore, often possesss endemic taxa, rare and endangered species which have been lost from the surrounding areas.