Issues on Environment, Biodiversity & Climate Change (Part-I)

Total Questions: 50

21. Three of the following criteria have contributed to the recognition of Western Ghats, Sri Lanka and Indo Burma regions as hotspots of biodiversity: [2011-1]

1. Species richness

2. Vegetation density

3. Endemism

4. Ethno-botanical importance

5. Threat perception

6. Adaption of flora and fauna to warm and humid conditions

Which three of the above are correct criteria in this context?

(a) 1, 2 and 6
(b) 2, 4 and 6
(c) 1, 3 and 5
(d) 3, 4 and 6

Correct Answer: (c) 1, 3 and 5

Solution:To qualify as a hotspot, a region must meet two strict criteria: it must contain at least 1,500 species of vascular plants (0.5 percent of the world's total) as endemics, and it has to have lost at least 70 percent of its original habitat. So we choose Species richness as well as Endemism. Along with this Threat perception is necessary to take, because it makes the base of this concept. Adaptation of flora is an arbitrary option, Ethno-botanical importance does nothing with the Biodiversity Hotspot selection criteria, vegetation Density is also discarded.

22. The Himalayan range is very rich in species diversity. Which one among the following is the most appropriate reason for this phenomenon ? [2011-1]

(a) It has a high rainfall that supports luxuriant vegetative growth
(b) It is a confluence of different bio-geographical zones.
(c) Exotic and invasive species have not been introduced in this region.
(d) It has less human interference.

Correct Answer: (b) It is a confluence of different bio-geographical zones.

Solution:Himalayas and its adjoining areas are marked as a confluence of several biogeographical realms. It has verity of forest type and is rich in zoo-biogeographic region.

23. There is a concern over the increase in harmful algal blooms in the seawaters of India. What could be the causative factors for this phenomenon? [2011-1]

(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) 1, 2 and 3

Correct Answer: (d) 1, 2 and 3

Solution:Algae multiply rapidly when nutrients are present. So, discharge of nutrients favour algae and subsequently algal bloom growth from estuaries to sea. The run off from the land during the monsoon bring salts which favours the growth of algae. Upwelling of the sea water brings the nutrients to top level leading to rapid algae multiplication.

24. Consider the following: [2011-1]

1. Photosynthesis

2. Respiration.

3. Decay of organic matter

4. Volcanic action.

Which of the above add carbon dioxide to the carbon cycle on earth?

(a) 1 and 4 only
(b) 2 and 3 only
(c) 2, 3 and 4 only
(d) 1 and 4

Correct Answer: (c) 2, 3 and 4 only

Solution:Photosynthesis by plants removes about 120 billion tons of carbon from the air per year, but plant decomposition returns about the same amount. When the organic matter is oxidized through respiration, the reverse of photosynthesis takes place. Respiration releases CO₂, into the atmosphere. Respiration and photosynthesis occur at nearly equal rates over one year. Volcanic eruptions and metamorphism release gases into the atmosphere. Volcanic gases are primarily water vapor, carbon dioxide and Sulphur dioxide.

25. A sandy and saline area is the natural habitat of an Indian animal species. The animal has no predators in that area but its existence is threatened due to the destruction of its habitat Which one of the following could be that animal? [2011-1]

(a) Indian wild buffalo
(b) Indian wild ass
(c) Indian wild boar
(d) Indian gazelle

Correct Answer: (b) Indian wild ass

Solution:The Indian wild ass are also called as ghudkhur in local Gujarati language, is a subspecies of the onager native of South Asia. It is unknown how they disappeared though they have never been hunting target during any emperors in India.

The history speaks that their number has been declining after due to diseases such as surra and horse sickness. The process related to salt activities have also been a reason behind it.

26. Biodiversity forms the basis for human existence in the following ways: [2011-1]

1. Soil formation

2. Prevention of soil erosion

3. Recycling of waste

4. Pollination of crops

Select the correct answer using the codes given below

(a) 1,2 and 3 only
(b) 2, 3 and 4 only
(c) 1 and 4 only
(d) 1, 2, 3 and 4 only

Correct Answer: (d) 1, 2, 3 and 4 only

Solution:Biological diversity helps in the formation and maintenance of soil structure and the retention of moisture and nutrient levels. Biodiversity supports ecosystem services including air quality, climate water purification, pollination, and prevention of erosion.

27. Which one of the following is not a site for in-situ method of conservation of flora ? [2011-1]

(a) Biosphere Reserve
(b) Botanical Garden
(c) National Park
(d) Wildlife Sanctuary

Correct Answer: (b) Botanical Garden

Solution:Zoo and botanical gardens are the most conventional methods of ex-situ conservation, rest all options are natural habitats so are of in-situ conservation.

28. The 2004 Tsunami made people realize that mangroves can serve as a reliable safety hedge against coastal calamities. How do mangroves function as a safety hedge? [2011-1]

(a) The mangrove swamps separate the human settlements from the sea by a wide zone in which people neither live nor venture out.
(b) The mangroves provide both food and medicines which people are in need of after any natural disaster.
(c) The mangrove trees are tall with dense canopies and serve as an excellent shelter during a cyclone or tsunami.
(d) The mangrove trees do not get uprooted by storms and tides because of their extensive roots.

Correct Answer: (d) The mangrove trees do not get uprooted by storms and tides because of their extensive roots.

Solution:The mangrove trees do not get uprooted by storms and tides because of their extensive roots.

29. The "Red Data Books" published by the International Union for Conservation of Nature and Natural resources (IUCN) contain lists of? [2011-1]

1. Endemic plant and animal species present in the biodiversity hotspots.

2. Threatened plant and animal species.

3. Protected sites for conservation of nature and natural resources in various countries.

Select the correct answer using the codes given below:

(a) 1 and 3
(b) 2 only
(c) 2 and 3
(d) 3 only

Correct Answer: (b) 2 only

Solution:The red data book contains only 8 lists of threatened plant and animal species.

30. Consider the following statements: [2011-1]

Consider the following statements:

1. Biodiversity is normally greater in the lower latitudes as compared to the higher latitudes.

2. Along the mountain gradients, biodiversity is normally greater in the lower altitudes as compared to the higher altitudes.

Which of the statements given above is/are correct?

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer: (c) Both 1 and 2

Solution:Biodiversity is higher in the low latitudes as compared to the higher latitudes as the habitat tolerance level is very narrow at greater latitude.

Mountains have high range of species at the low altitude as they can support larger number of species due to climatic condition.

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