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?

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]

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.
Bio-geographical zones are large areas characterized by similar flora and fauna. The Earth is divided into several such realms. The Himalayan Range is a classic example of a transition zone or ecotone between major realms, facilitating the presence of species from both sides, alongside endemic species (found only in that region).
  • Biodiversity hotspots are regions with high levels of endemic species and significant habitat loss. The Himalayas are recognized as one such hotspot, emphasizing their global importance for conservation
  • Altitude variation in the Himalayas also plays a crucial role, creating diverse microhabitats from tropical forests at lower elevations to alpine meadows and cold deserts at higher altitudes, further contributing to species diversity.

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]

  1. Discharge of nutrients from the estuaries.
  2. Run-off from the land during the monsoon.
  3. Upwelling in the seas.
    Select the correct answer from the codes given below:
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.
Types of Algae in Blooms
  • Cyanobacteria (Blue-Green Algae): Certain species of cyanobacteria can form toxic algal blooms. The toxins produced by these algae, such as microcystins and saxitoxins, can be harmful to animals and humans.
  • Dinoflagellates: Some dinoflagellates, a type of microscopic algae, can cause red tide events. These algae can produce toxins that can lead to fish kills and harm marine organisms
  • Diatoms: Diatoms are a group of algae that can contribute to non-toxic algal blooms. While they are generally not harmful, their rapid growth can still have ecological consequences.
  • Golden algae: Although found mostly in oceans, golden algae (Prymnesium parvum) are an emerging problem in freshwater rivers, reservoirs, and lakes, particularly those with higher salinity (due to higher mineral content).

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?

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]

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

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.
Biodiversity in India
  • India is one of the 17 world's recognised mega-diverse countries, home to roughly 7-8% of all documented species and four of the 36 globally defined biodiversity hotspots
  • India's rich biodiversity: Because of the varying edaphic, climatic, and topographic conditions as well as years of geological stability, a diverse range of ecosystems and habitats have emerged in India including forests, grasslands, wetlands, deserts, and coastal and marine ecosystems.
  • Flora and fauna: Over 1,03,258 species of fauna and 55,048 species of flora have been documented in the 10 biogeographic zones of the country.
  • India has 28,948 endemic species of fauna, while 12,095 known plant species are endemic
  • Wetland ecosystem: India has a variety of wetland ecosystems ranging from high-altitude cold desert wetlands to hot and humid wetlands in coastal zones with diverse flora and fauna.
  • About 4,445 km2 of the country is under mangroves.
  • India is blessed with rich fish diversity with a current distribution of 783 species of freshwater fishes which includes 223 endemic fishes.
  • India currently has 80 Ramsar Sites.
  • Forest cover: 23.39% of the geographical area of the country is under forest cover with 16 major forest types and 251 sub-types.

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

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.
  • In-situ Conservation is the process of protection and maintenance of ecosystems and natural habitats so that species survive and thrive in their native environment.
  • It focuses on preserving entire ecosystems instead of isolated species.
  • Focus is on maintaining the natural processes and interactions important for ecosystem resilience.
  • It can be species- centered like protecting specific endangered species or ecosystem based like conserving whole habitats.
  • The in-situ conservation method works by establishing the protected areas and providing a safe habitat for wildlife as well as help balance human requirements with conservation goals.

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]

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.

Mangroves are uniquely adapted to thrive in coastal ecosystems through features like salt tolerance, aerial roots for respiration, and vivipary for seed germination in saline conditions. These adaptations not only help them survive harsh environments but also contribute significantly to carbon sequestration, playing a vital role in climate change mitigation.

  • Salt Tolerance: They possess specialised root structures, such as salt-filtering roots and salt-excreting leaves, to manage high salinity levels.
  • Aerial Roots (Pneumatophores): These roots help in respiration by obtaining oxygen from the air in waterlogged soils.
  • Prop Roots: Provide stability against tidal waves and storm surges.
  • Vivipary (Seed Germination): Seeds germinate while still attached to the parent tree to overcome the challenge of germination in saline water.
  • Efficient Carbon Sequestration: Mangroves are among the most carbon-rich ecosystems, playing a vital role in mitigating climate change.

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:

Correct Answer: (b) 2 only
Solution:The red data book contains only 8 lists of threatened plant and animal species.

IUCN Red List or Red Data List or Red Book

  • The IUCN Red List of Threatened Species, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species.
  • When discussing the IUCN Red List, the official term "threatened" is a grouping of three categories: Critically Endangered, Endangered, and Vulnerable.

  • The pink pages in this publication include the critically endangered species.
  • As the status of the species changes, new pages are sent to the subscribers.
  • Green pages are used for those species that were formerly endangered but have now recovered to a point where they are no longer threatened.
  • With passing time, the number of pink pages continue to increase.

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?

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.