Question 1

With reference to aquatic organisms, consider the following statements:
1. Nekton are microscopic organisms whose distribution is largely controlled by water currents.
2. Periphyton are unattached organisms that live at the air-water interface, such as floating plants.
3. Benthic organisms are those found living in the bottom of the water mass.

Accepted Answer

Only one. Statement 1 is incorrect. It describes Plankton, which are microscopic and have limited locomotory power, making their distribution controlled by currents. Nekton are swimmers, relatively large and powerful enough to overcome water currents. Statement 2 is incorrect. It describes Neuston, which are unattached organisms living at the air-water interface. Periphyton are organisms that remain attached to stems and leaves of rooted plants. Statement 3 is correct. Benthos are defined as organisms found living in the bottom of the water mass. Therefore, only one statement is correct.

Question 2

Consider the following statements regarding the factors limiting the productivity of aquatic habitats:
1. In the photic zone of an aquatic ecosystem, only respiration activity takes place.
2. The aphotic zone is characterized by the restriction of plant growth due to limited light penetration.
3. The photic zone extends from the lake surface down to where the light level is 1% of that at the surface.

Accepted Answer

Only two. Statement 1 is incorrect. In the photic zone, both photosynthesis and respiration activity take place. The aphotic zone is where only respiration occurs. Statement 2 is correct. The lower layers of aquatic ecosystems where light penetration is restricted, and consequently plant growth is restricted, form the aphotic zone. Statement 3 is correct. The photic (or 'euphotic') zone is the lighted portion that extends from the lake surface down to where the light level is 1% of that at the surface. Therefore, two statements are correct.

Question 3

Consider the following pairs:
1. Brackish water ecosystem : Salt content always less than 5 ppt
2. Marine ecosystem : Examples include estuaries and salt marshes
3. Fresh water ecosystem : Examples include lakes and rivers
How many of the above pairs are correctly matched?

Accepted Answer

Only one pair. Pair 1 is incorrectly matched. A salt content of less than 5 ppt (parts per thousand) is characteristic of fresh water ecosystems. Brackish water ecosystems have a salt content between 5 to 35 ppt. Pair 2 is incorrectly matched. Estuaries and salt marshes are examples of brackish water ecosystems, not marine ecosystems. Marine ecosystems have a salt concentration of 35 ppt or above. Pair 3 is correctly matched. Fresh water ecosystems have very low salt content and include lakes, ponds, streams, and rivers. Therefore, only one pair is correctly matched.

Question 4

Consider the following statements regarding the nutritional requirements of phytoplankton:
1. All phytoplankton require silicate in significant amounts for their growth and reproduction.
2. Iron is required in trace amounts and its low concentration is a limiting factor for phytoplankton growth in large oceanic areas.
3. Some phytoplankton are capable of fixing nitrogen, which allows them to thrive in regions where nitrate concentrations are low.
How many of the statements given above are correct?

Accepted Answer

Only two. Statement 1 is incorrect. Diatoms and silicoflagellates require silicate in significant amounts, but this requirement is not universal for all phytoplankton. Statement 2 is correct. Iron is a trace nutrient, and its low availability limits phytoplankton growth in vast ocean areas. Statement 3 is correct. Certain phytoplankton can fix atmospheric nitrogen, enabling them to grow in environments with low levels of dissolved nitrate.

Question 5

With reference to the distribution and productivity of phytoplankton, consider the following statements:
1. Marine phytoplankton are generally found to be uniformly distributed across the world's oceans.
2. The highest concentrations of phytoplankton are typically found in the tropics and subtropics due to high light availability.
3. Phytoplankton productivity is confined to the euphotic zone, where sufficient sunlight for net productivity is available.
How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. Marine phytoplankton are not uniformly distributed; their concentrations vary significantly by region. Statement 2 is incorrect. The highest concentrations of phytoplankton are found at high latitudes and in upwelling zones, not in the tropics and subtropics, which have 10 to 100 times lower concentrations. Statement 3 is correct. Phytoplankton productivity is limited to the euphotic zone, which is the upper layer of the water column penetrated by sufficient sunlight to support net photosynthesis.

Question 6

Consider the following pairs:
1. Factor : Photosynthesis Rate - A continuous increase with rising temperature.
2. Organism : Habitat - Sea snakes in the deep waters of the Indian Ocean.
3. Nutrient : Organism Group - Silicate required by all phytoplankton.
4. Factor : Phytoplankton Crop - Grazing by zooplankton.
How many of the pairs given above are correctly matched?

Accepted Answer

Only one pair. Pair 1 is incorrectly matched. The rate of photosynthesis increases with temperature only up to a certain point, after which it diminishes sharply. Pair 2 is incorrectly matched. Sea snakes are found in shallow waters, not deep waters. Pair 3 is incorrectly matched. Silicate is required in significant amounts by diatoms and silicoflagellates, not all phytoplankton. Pair 4 is correctly matched. The grazing rate of zooplankton is a major factor that influences the standing crop of phytoplankton.

Question 7

Consider the following statements regarding the role of phytoplankton in the carbon cycle:
1. During photosynthesis, carbon from carbon dioxide is incorporated into the phytoplankton.
2. The 'biological carbon pump' is a process that transfers approximately 10 gigatonnes of carbon annually from the deep ocean to the atmosphere.
3. Minor fluctuations in the growth of phytoplankton populations can have feedback effects on global surface temperatures.
How many of the statements given above are correct?

Accepted Answer

Only two. Statement 1 is correct. Carbon dioxide is consumed by phytoplankton during photosynthesis, and the carbon is incorporated into their structure. Statement 2 is incorrect. The biological carbon pump transfers carbon from the atmosphere to the deep ocean, not the other way around. Statement 3 is correct. Even small changes in phytoplankton growth can alter atmospheric carbon dioxide concentrations, which in turn can feed back to affect global surface temperatures.

Question 8

With reference to aquatic food webs, consider the following statements:
1. Phytoplankton are primary producers that form the foundation of these webs.
2. The diet of phytoplankton consists of microscopic animal-like zooplankton.
3. Organisms ranging from small invertebrates to large whales directly or indirectly depend on phytoplankton for food.
How many of the statements given above are correct?

Accepted Answer

Only two. Statement 1 is correct. Phytoplankton are the primary producers at the base of the aquatic food web. Statement 2 is incorrect. Phytoplankton are producers, not consumers; they produce their own food via photosynthesis. It is the zooplankton that graze on phytoplankton. Statement 3 is correct. The aquatic food web is structured such that phytoplankton feed a wide range of organisms, from zooplankton and small invertebrates to large animals like whales.

Question 9

Consider the following statements:
1. Sharks use a sensory organ known as the 'ampullae of Lorenzini' to detect phytoplankton blooms.
2. Silverfish are a type of invertebrate that grazes on phytoplankton in near-surface waters.
3. Most of the carbon incorporated in phytoplankton is returned to near-surface waters when they are eaten or decompose.
How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. The ampullae of Lorenzini is a sensory organ used by sharks to detect the electrical fields of their prey, not to detect phytoplankton. Statement 2 is incorrect. Silverfish are terrestrial insects that can be found in environments like old books; they are not aquatic invertebrates that graze on phytoplankton. Statement 3 is correct. While some carbon sinks to the deep ocean, most is returned to near-surface waters through decomposition or consumption within the food web.

Question 10

With reference to Sea grasses, consider the following statements:
1. They are a group of marine flowering plants adapted to life in salt water.
2. They primarily grow in deep oceanic trenches with sandy or muddy bottoms.
3. The rich growth of seagrasses along the Indian coast is attributed to high salinity and clarity of water.

How many of the statements given above are correct?

Accepted Answer

Only two. Statement 1 is correct. Sea grasses are marine flowering plants (angiosperms) and are the only group of higher plants adapted to life in the salt water. Statement 2 is incorrect. Sea grasses grow in shallow coastal waters, not deep oceanic trenches. They are commonly distributed from the inter-tidal to the sub-tidal region down to 8 m depth. Statement 3 is correct. The rich growth of seagrasses along the Tamil Nadu coast and Lakshadweep islands is mainly due to high salinity, clarity of the water, and a sandy substratum.

Question 11

Consider the following statements regarding the ecological functions of Sea grass beds:
1. They physically help to amplify wave and current energy in coastal areas.
2. They act as nutrient sinks, filtering nutrient and chemical inputs to the marine environment.
3. They contribute to coastal erosion by destabilising bottom sediments.

How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. Sea grass beds physically help to reduce wave and current energy, thereby protecting coastlines. Statement 2 is correct. Seagrasses on reef flats and near estuaries are nutrient sinks, buffering or filtering nutrient and chemical inputs. Statement 3 is incorrect. Sea grass beds help to stabilise bottom sediments and control erosion, which is the opposite of the claim made in the statement.

Question 12

Consider the following statements:
1. In India, major Sea grass meadows occur primarily around the Andaman and Nicobar islands.
2. Dugong, a species of fish dependent on sea grass for food, is on the verge of extinction.
3. Threats to sea grass beds include eutrophication, siltation, and trawling.

How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. Major Sea grass meadows in India occur along the southeast coast of Tamil Nadu and in the lagoons of a few Lakshadweep islands. There are only a few grass beds around the Andaman and Nicobar islands. Statement 2 is incorrect. Dugong is a mammal, not a species of fish, that is dependent on sea grass for food. Statement 3 is correct. Eutrophication, siltation, trawling, coastal engineering constructions, and over-exploitation are listed as major threats to sea grass beds.

Question 13

With reference to seaweeds, consider the following statements:
1. Seaweeds are thalloid plants characterized by the presence of differentiated true roots, stems, and leaves.
2. Due to their ability to accumulate certain substances, seaweeds can be used as potential indicators of heavy metal pollution.
3. The primary commercial product derived from the controlled decomposition of seaweed is hydrogen sulfide for industrial use.

How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. Seaweeds are macroscopic algae defined as thalloid plants, which means they have no differentiation of true tissues such as roots, stems, and leaves. They possess leaf-like appendages. Statement 2 is correct. Seaweeds have the ability to bind and accumulate metals strongly, making them potential indicators of pollution, particularly from heavy metals. Statement 3 is incorrect. Hydrogen sulfide is a highly toxic gas produced from rotting seaweed and is considered a harmful effect, not a primary commercial product. Commercially valuable products extracted from seaweeds include agar-agar and alginates, and methane can be produced from their biodegradation.

Question 14

Consider the following statements regarding the ecological and economic roles of seaweeds:
1. Seaweeds are typically found attached to substrata in the deep, aphotic zones of the ocean.
2. Through biodegradation, seaweeds can be processed to produce methane in large quantities.
3. Seaweeds contribute to coastal ecosystems by serving as a source of sediment and providing habitat for fish breeding.

How many of the statements given above are correct?

Accepted Answer

Only two. Statement 1 is incorrect. Seaweeds grow in shallow coastal waters, specifically in the intertidal and shallow sub-tidal zones where sizable substrata are available. They require light for photosynthesis and are not found in deep, aphotic zones. Statement 2 is correct. The biodegradation of seaweeds can yield economically important gases like methane in large quantities. Statement 3 is correct. Among their ecological functions, seaweeds act as a source of sediment and their structures provide habitats that serve as fish breeding grounds.

Question 15

Consider the following pairs:
1. Rotting Seaweed : Methane Gas
2. Seaweed Extract : Antibacterial Activity
3. Seaweed Appendage : True Leaf
4. Seaweed Pigmentation : Basis for Classification

How many of the pairs given above are correctly matched?

Accepted Answer

Only two pairs. Pair 1 is incorrectly matched. Rotting seaweed is a potent source of hydrogen sulfide, a highly toxic gas. Methane is produced via the biodegradation of seaweeds, not simply from rotting. Pair 2 is correctly matched. Extracts of some seaweed species show antibacterial activity. Pair 3 is incorrectly matched. Seaweeds are thalloid plants, meaning they lack differentiation of true tissues. They have leaf-like appendages, not true leaves. Pair 4 is correctly matched. Seaweeds are broadly classified into different classes (e.g., blue-green, green, brown, red) based on the colour of their pigmentation.

Question 16

Consider the following statements regarding the physical and biological characteristics of lakes:
1. Due to water's low specific heat compared to air, its temperature changes more rapidly.
2. The relative stability of water temperature allows aquatic organisms to develop a wide tolerance limit for temperature changes.
3. The transparency of lake water, which affects photosynthetic activity, is reduced by suspended particulate matter such as clay and silt.

How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. Water has a considerably higher specific heat than air, meaning larger amounts of heat energy are required to change its temperature. Consequently, water temperature changes less rapidly than air temperature. Statement 2 is incorrect. Because water temperatures are less subject to change, aquatic organisms have adapted to this stability by having a narrow temperature tolerance limit. Even small changes in water temperature can be a significant threat to their survival. Statement 3 is correct. Suspended particulate matter like clay, silt, and phytoplankton increases the turbidity of water, which limits the penetration of light and thereby restricts the extent of photosynthetic activity.

Question 17

Consider the following statements regarding lakes in India:
1. The vast majority of lakes in India are classified as oligotrophic due to low levels of nutrient runoff.
2. Most of India's natural lakes are found in the semiarid and arid regions of western and peninsular India.
3. The accelerated nutrient enrichment of a lake caused by agricultural runoff is known as 'cultural eutrophication'.

How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. The vast majority of lakes in India are either eutrophic or mesotrophic. This is due to significant nutrient inputs derived from their surroundings or from organic wastes entering them. Statement 2 is incorrect. Most of India's natural lakes are located in the Himalayan region and the floodplains of the Indus, Ganga, and Brahmaputra rivers. The water bodies in the semiarid and arid regions are predominantly man-made constructions. Statement 3 is correct. Natural eutrophication is the slow nutrient enrichment of lakes over millennia. When this process is accelerated by human activities, such as the discharge of agricultural runoff or wastewaters, it is termed 'cultural eutrophication'.

Question 18

Consider the following statements:
Statement I: Over geological time, lakes undergo a process of 'ageing' where they accumulate matter and gradually get filled up.
Statement II: Lakes continuously receive water from surface runoff, which carries various chemical substances and eroded mineral matter.
Statement III: The process of nutrient-enrichment in lakes, known as eutrophication, promotes the growth of algae and other aquatic life.

Which one of the following is correct in respect of the above statements?

Accepted Answer

Both Statement II and Statement III are correct and both are independent explanations for Statement I.. Statement I is a correct description of the long-term ageing process of lakes. Statement II is also correct; it describes the primary mechanism by which lakes receive inorganic inputs like mineral matter from their catchment area. Statement III is also correct; it describes the biological component of lake ageing, where nutrient enrichment leads to an increase in organic matter (algae, plants). The 'filling up' process mentioned in Statement I is a result of both the accumulation of mineral matter (explained by Statement II) and the accumulation of organic matter from increased biological productivity (explained by Statement III). Therefore, both Statement II and Statement III are correct and independently contribute to explaining the phenomenon in Statement I.

Question 19

With reference to the characteristics of wetland ecosystems, consider the following statements:

1. For an area to be classified as a wetland, it must be permanently covered by water or have permanently waterlogged soil.
2. The defining characteristic of wetland soils is their high oxygen content, which supports a wide variety of plant life.
3. The official definition of a wetland includes only natural areas of marsh, fen, or peatland with static, fresh water.

How many of the statements given above are correct?

Accepted Answer

None. Statement 1 is incorrect. A wetland can be permanent or temporary. The soil needs to be waterlogged for at least seven days during the growing season, not permanently. Statement 2 is incorrect. Wetland soils are described as 'hydric soils', which are characterized by not having enough oxygen available for some plants. Statement 3 is incorrect. The definition of a wetland includes areas that are natural or artificial, permanent or temporary, with water that is static or flowing, and can be fresh, brackish, or salt.

Question 20

Consider the following pairs with reference to the classification of wetlands:

1. Ox-bow Lakes : Man-made Inland Wetland
2. Coral reef : Man-made Coastal Wetland
3. Salt pans : Natural Coastal Wetland
4. Reservoirs : Man-made Inland Wetland

How many of the pairs given above are correctly matched?

Accepted Answer

Only one pair. Pair 1 is incorrectly matched. Ox-bow lakes are classified as Natural Inland Wetlands. Pair 2 is incorrectly matched. Coral reefs are classified as Natural Coastal Wetlands. Pair 3 is incorrectly matched. Salt pans are classified as Man-made Coastal Wetlands. Pair 4 is correctly matched. Reservoirs are classified as Man-made Inland Wetlands. Therefore, only one pair is correctly matched.

Question 21

Consider the following statements regarding the criteria for identification of Wetlands of National Importance:

1. A wetland is identified as nationally important if it regularly supports 1% of the individuals in a population of one species or subspecies of any animal, not just waterbirds.
2. A wetland can be identified as important if it serves as a spawning ground or migration path on which fish stocks depend, regardless of whether those stocks are located within the wetland or elsewhere.
3. To meet the water bird criterion, a site must regularly support 20,000 or more individuals, but this count includes both water birds and terrestrial birds found in the vicinity.

How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. The criterion specifies supporting 1% of the individuals in a population of one species or subspecies of 'waterbirds' specifically. Statement 2 is correct. The criterion states the wetland can be an important source of food, spawning ground, nursery and/or migration path on which fish stocks, 'either within the wetland or elsewhere', depend. Statement 3 is incorrect. The criterion explicitly mentions '20,000 or more water birds', not a mix of water birds and terrestrial birds. Therefore, only one statement is correct.

Question 22

Consider the following statements regarding the characteristics of estuarine ecosystems:
1. Estuaries are characterized by significant wave action, which is essential for mixing freshwater and saltwater.
2. Due to their semi-enclosed nature, estuaries are ineffective at trapping sediments and act as poor natural water filters for pollutants.
3. Estuaries are considered one of the most productive water bodies in the world.
How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. An estuary has very little wave action, which allows it to provide a calm refuge from the open sea. Statement 2 is incorrect. Estuaries act as a filter for some dissolved constituents in river water and are important for trapping suspended mud and sand. A healthy estuary absorbs, traps, and detoxifies pollutants. Statement 3 is correct. Estuaries are the most productive water bodies globally, as they receive a high amount of nutrients from both riverine and marine sources.

Question 23

Consider the following statements:
Statement I: Only certain types of plants and animals specially adapted to 'brackish' conditions can flourish in estuaries.
Statement II: Estuaries exhibit a complete salinity gradient, ranging from nearly 0 ppt at the river end to 35 ppt at the sea end.
Which one of the following is correct in respect of the above statements?

Accepted Answer

Both Statement I and Statement II are correct and Statement II is the correct explanation for Statement I.. Statement I is correct; the unique and fluctuating conditions in an estuary mean that only specially adapted organisms can thrive there. Statement II is also correct; estuaries are defined by the mixing of freshwater and saltwater, creating a full salinity gradient. Statement II provides the correct explanation for Statement I because the wide and variable salinity is a primary environmental stressor that necessitates the special adaptations mentioned in Statement I.

Question 24

With reference to estuarine ecosystems, consider the following statements:
1. All estuaries are formed exclusively by the geological process of rising sea levels.
2. Estuaries are characterized by a uniform salinity of approximately 35 ppt throughout the entire water body.
3. Human settlements utilize estuaries for commerce, and the ecosystem itself can trap and detoxify certain pollutants.
How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. Estuaries are grouped into four geomorphic categories based on their formation: rising sea level, movement of sand and sandbars, glacial processes, and tectonic processes. Statement 2 is incorrect. Estuaries exhibit a complete salinity range from 0-35 ppt, with salinity varying from the head (river end) to the mouth (sea end). Statement 3 is correct. The banks of estuarine channels are favored locations for human settlements for activities like fishing and commerce. A healthy estuary also absorbs, traps, and detoxifies pollutants, acting as a natural water filter.

Question 25

Consider the following statements regarding the physiological adaptations of mangroves:
1. Viviparity is an adaptive mechanism primarily for absorbing fresh water from saline environments.
2. Pneumatophores are vertical air roots that grow upwards from the mud to facilitate respiration in anaerobic conditions.
3. All mangrove species possess salt-secreting glands on their leaves as the sole mechanism for managing salinity stress.
How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. Viviparity is a mode of reproduction where seeds germinate while still attached to the parent tree. This adaptation helps overcome the challenges of germination in saline water, not water absorption. Statement 2 is correct. In water-logged, anaerobic soils, mangroves like Avicennia develop pneumatophores, which are specialized aerial roots that grow upwards to obtain oxygen for respiration. Statement 3 is incorrect. Mangroves employ multiple strategies for salt management. While some species secrete salt through leaf glands, others have mechanisms to block salt absorption at the root level. It is not a universal or sole mechanism.

Question 26

With reference to the ecological roles of mangroves, consider the following statements:
1. By impeding water flow, mangrove root systems enhance the deposition of sediment and contribute to stabilizing coastal shores.
2. The anoxic sediments under mangroves act as sources, releasing a variety of scavenged heavy metals into the coastal ecosystem.
3. Mangroves are known to release carbon dioxide and absorb oxygen, contributing to local atmospheric changes.
How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is correct. The dense network of prop roots and pneumatophores in mangrove forests slows down water currents, which promotes the settling and accumulation of sediments, thereby stabilizing coastlines against erosion. Statement 2 is incorrect. The fine, anoxic sediments found in mangrove ecosystems function as sinks, not sources, for heavy metals. They trap and immobilize these metals, which are scavenged from the water column, effectively removing them from the immediate environment. Statement 3 is incorrect. Mangroves, like other photosynthetic plants, perform gas exchange that involves taking in carbon dioxide from the atmosphere for photosynthesis and releasing oxygen as a byproduct.

Question 27

Consider the following characteristics and functions associated with mangroves:
1. Mangroves primarily act as carbon sinks by storing carbon in their above-ground biomass, such as leaves and branches, with negligible storage in the underlying sediment.
2. Lenticellated bark is a common feature in mangroves that facilitates nutrient absorption from the atmosphere.
3. Adventitious roots that emerge from the main trunk above ground level, known as stilt roots, provide structural support in unstable, muddy soils.
How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. Mangrove ecosystems are highly effective carbon sinks, sequestering significant amounts of carbon not only in their above-ground biomass but also, and more substantially, in their extensive root systems and the surrounding organic-rich sediments (silt). Statement 2 is incorrect. Lenticels in the bark of mangroves are pores that facilitate gas exchange and water loss, not nutrient absorption from the atmosphere. Statement 3 is correct. Stilt roots, a type of adventitious root, grow from the trunk and branches down into the substrate. They provide crucial stability and support for the mangrove tree in soft, waterlogged, and unstable soils typical of intertidal zones.

Question 28

Consider the following statements regarding the causes of coral reef bleaching:
1. Sudden exposure of reef flat corals to the atmosphere during extreme low tides can induce bleaching.
2. An increase in ambient elemental nutrient concentrations, such as ammonia and nitrate, is a direct cause of zooxanthellae loss.
3. Rapid dilution of reef waters from storm-generated precipitation and runoff has been demonstrated to cause coral reef bleaching.
How many of the statements given above are correct?

Accepted Answer

Only two. Statement 1 is correct. Subaerial exposure, which is the exposure of reef flat corals to the atmosphere during events like extreme low tides, can induce bleaching. Statement 2 is incorrect. An increase in ambient elemental nutrient concentrations like ammonia and nitrate actually increases zooxanthellae densities. While this process, known as eutrophication, can have secondary adverse effects, it is not directly involved in zooxanthellae loss (bleaching). Statement 3 is correct. Freshwater dilution from storm-generated precipitation and runoff can cause coral reef bleaching, although such events are typically rare and localized near the shore.

Question 29

With reference to the Coastal Regulation Zone (CRZ) Notification (2011), consider the following activities:
1. Projects relating to the Department of Atomic Energy
2. Installation of weather radar for cyclone monitoring
3. Construction of new ports and harbours
4. Construction of trans-harbour sea links
How many of the above are permitted construction activities in CRZ-I areas, which include mangroves and coral reefs?

Accepted Answer

Only three. In ecologically sensitive areas categorized as CRZ-I, new constructions are generally not permitted. However, there are specific exceptions. Activity 1 is a permitted exception. Projects relating to the Department of Atomic Energy are allowed. Activity 2 is a permitted exception. Installation of weather radar by the Indian Meteorological Department is allowed. Activity 3 is not a permitted exception. The list of exceptions does not include the construction of new ports and harbours. Activity 4 is a permitted exception. Construction of trans-harbour sea links is allowed, with the condition that it does not affect the tidal flow of water. Therefore, only three of the listed activities are permitted.

Question 30

Consider the following statements:
Statement I: Coral reefs in India are afforded the highest degree of protection under the country's legal framework.
Statement II: Coral reef is included in Schedule I of the Wild Life Protection Act, 1972.
Statement III: The Ministry of Environment & Forests provides financial assistance to Coastal States for the conservation and management of coral reefs under a Centrally Sponsored Scheme.
Which one of the following is correct in respect of the above statements?

Accepted Answer

Both Statement II and Statement III are correct, but only Statement II is the correct explanation for Statement I.. Statement I is correct. The inclusion of coral reefs in the highest protection category of national law signifies their protected status. Statement II is correct. Coral reefs are listed in Schedule I of the Wild Life Protection Act, 1972. This inclusion is the specific legal provision that affords them the 'highest degree of protection', thus Statement II is the correct explanation for Statement I. Statement III is also correct. The Ministry does provide financial assistance for coral reef conservation through a Centrally Sponsored Scheme. However, this is a promotional measure involving financial aid, not the legal basis for the 'highest degree of protection' mentioned in Statement I. Therefore, while both statements II and III are correct facts, only Statement II serves as the direct legal explanation for Statement I.

Question 31

Consider the following statements regarding the institutional framework for Ganga rejuvenation:
1. The National Ganga River Basin Authority (NGRBA) is an empowered body chaired by the Union Finance Minister.
2. The "Clean Ganga Fund" is operated through a bank account by a Trust headed by the Prime Minister.
3. The proposed "NRI Ganga Fund" is to be set up under the aegis of the Ministry of Water Resources, River Development and Ganga Rejuvenation.
How many of the statements given above are correct?

Accepted Answer

None. Statement 1 is incorrect. The National Ganga River Basin Authority (NGRBA) is chaired by the Prime Minister. Statement 2 is incorrect. The "Clean Ganga Fund" is operated by a Trust to be headed by the Finance Minister. Statement 3 is incorrect. The "NRI Ganga Fund" was proposed to be set up under the aegis of the Ministry of Overseas Indian Affairs or the Ministry of Finance.

Question 32

With reference to various Ganga rejuvenation initiatives, consider the following statements:
1. The Ganga Action Plan, launched in 1986, had the specific objective that by 2020, no untreated industrial waste would be released into the river.
2. The Clean Ganga Fund (CGF) is designated to finance a broad range of activities, including the control of non-point pollution from agricultural runoff and conservation of the river's biotic diversity.
3. The "Namami Gange" programme's scope is limited to setting up sustainable municipal sewage management systems under its 'Nirmal Dhara' component.
How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. The objective that by 2020, no untreated municipal sewage and industrial waste would be released was part of the "Mission Clean Ganga" announced in 2009, not the Ganga Action Plan of 1986. Statement 2 is correct. Activities financed from the Clean Ganga Fund include control of non-point pollution from sources like agricultural runoff and the conservation of the river's biotic diversity. Statement 3 is incorrect. The "Namami Gange" programme is a comprehensive mission that also includes interventions like the development of Ghats and beautification of River Fronts at several cities, including Kedarnath, Haridwar, and Varanasi.

Question 33

Consider the following statements regarding the financial aspects of Ganga conservation efforts:
1. The "Namami Gange" program was launched with a budget of around Rs. 15,000 crore.
2. The "Clean Ganga Fund (CGF)" is established with voluntary contributions and offers domestic donors tax benefits analogous to the "Swachch Bharat Kosh".
3. The "NRI Ganga Fund" is designed to finance special projects and is operated by a Trust headed by the Finance Minister.
How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. The "Mission Clean Ganga" project had a budget of around Rs. 15,000 crore. The sum of Rs. 2,037 crores was set aside for the "Namami Gange" program. Statement 2 is correct. The Clean Ganga Fund is set up with voluntary contributions from residents, NRIs, and others, and domestic donors are eligible for tax benefits as in the case of "Swachch Bharat Kosh". Statement 3 is incorrect. While the NRI Ganga Fund is for financing special projects, the body operated by a Trust headed by the Finance Minister is the "Clean Ganga Fund (CGF)", not the NRI Ganga Fund.

Question 34

Consider the following statements regarding the Ganga Action Plan (GAP) and the Namami Gange program:

1. The Ganga Action Plan's primary focus was on the development of Ghats and the beautification of River Fronts.
2. The Namami Gange program was proposed as an Integrated Ganga Conservation Mission.
3. A core component of the Ganga Action Plan was 'Nirmal Dhara', aimed at sustainable municipal sewage management.

How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. The main objective of the Ganga Action Plan was pollution abatement through the interception, diversion, and treatment of domestic sewage and industrial wastes. The development of Ghats and beautification of River Fronts is an objective associated with the Namami Gange program. Statement 2 is correct. The Namami Gange program was proposed as an Integrated Ganga Conservation Mission. Statement 3 is incorrect. 'Nirmal Dhara' is a component proposed under the Namami Gange program, not the Ganga Action Plan.

Question 35

Consider the following pairs:

1. Namami Gange : River centric urban planning
2. Ganga Action Plan : Interception of only industrial chemical wastes
3. Nirmal Dhara : Beautification of River Fronts

How many of the pairs given above are correctly matched?

Accepted Answer

Only one pair. Pair 1 is correctly matched. The interventions at Ghats and River fronts under the Namami Gange program are intended to set the tone for a river centric urban planning process. Pair 2 is incorrectly matched. The Ganga Action Plan's objective was the treatment of both domestic sewage and toxic industrial chemical wastes, not just industrial wastes. Pair 3 is incorrectly matched. 'Nirmal Dhara' is a component of Namami Gange focused on ensuring sustainable municipal sewage management, whereas the beautification of River Fronts is a separate allocation mentioned under the same program.

Question 36

With reference to river conservation efforts in India, consider the following statements:

1. The Ganga Action Plan, launched in 1986, was primarily a pollution abatement scheme.
2. The Namami Gange program aims to consolidate existing ongoing efforts for Ganga rejuvenation.
3. Under the Namami Gange program, a specific financial allocation was made for the development of Ghats in cities including Delhi.

How many of the statements given above are correct?

Accepted Answer

All three. Statement 1 is correct. The Ganga Action Plan was launched on 14th January 1986 with the main objective of pollution abatement. Statement 2 is correct. The Namami Gange program approaches Ganga Rejuvenation by consolidating existing ongoing efforts and planning for future action. Statement 3 is correct. A sum of Rs. 100 crores was allocated for the development of Ghats and beautification of River Fronts at several locations, which explicitly includes Delhi.

Question 37

With reference to Plankton, consider the following statements:
1. Plankton possess strong locomotory power, which allows them to determine their distribution against prevailing water currents.
2. The growth rate and species diversity of plankton are generally low in tropical waters, particularly in mangrove ecosystems.
3. The term 'plankton' exclusively refers to microscopic animals like crustaceans and protozoans that float in surface waters.

Accepted Answer

None. Statement 1 is incorrect. The locomotory power of planktons is limited, and their distribution is largely controlled by water currents, not by their own movement against them. Statement 2 is incorrect. The growth rate, productivity, and species diversity of plankton in tropical waters, especially in mangrove waters, are high. Statement 3 is incorrect. The term 'plankton' includes both microscopic plants (phytoplankton) and animals (zooplankton).

Question 38

Consider the following statements regarding Phytoplankton:
1. Phytoplankton are responsible for producing approximately one-third of the oxygen generated by all plant life on Earth.
2. All phytoplankton are single-celled plants that obtain energy exclusively through the process of photosynthesis.
3. The total biomass of phytoplankton in aquatic environments is considerably smaller than the total biomass of plants on land.

Accepted Answer

None. Statement 1 is incorrect. Phytoplankton produce more than 60% of the oxygen produced from all plants, not a smaller fraction. Statement 2 is incorrect. While all phytoplankton photosynthesize, some can get additional energy by consuming other organisms. Furthermore, not all are single-celled plants; some are bacteria or protists. Statement 3 is incorrect. The total biomass of phytoplankton is many times greater than that of the total plants on land.

Question 39

Consider the following statements about the ecological role of Zooplankton:
1. Zooplankton function as primary producers in the aquatic food web, forming the base of the food chain.
2. The abundance of zooplankton is typically lower within mangrove waterways when compared to adjacent open coastal waters.
3. The species diversity and quality of zooplankton communities can be used as indicators to assess the fertility and health of an aquatic ecosystem.

Accepted Answer

Only one. Statement 1 is incorrect. Zooplankton are consumers that transfer organic matter from primary producers (like phytoplankton) to secondary consumers; they are not primary producers themselves. Statement 2 is incorrect. Zooplankton are more abundant within mangrove waterways than in adjacent coastal waters. Statement 3 is correct. Zooplankton communities, based on their quality and species diversity, are utilized for assessing the productivity, fishery resource potential, fertility, and health status of an ecosystem.

Question 40

Consider the following statements regarding the ecological characteristics of wetlands:
1. As per the Ramsar Convention, the definition includes marine areas where depth at low tide does not exceed six meters.
2. They are characterized by hydric soils, which are oxygen-rich environments promoting rapid decomposition.
3. The dominant food chain pathway in most wetland ecosystems is based on grazing on living plants.
How many of the above statements are correct?

Accepted Answer

Only one. Statement 1 is correct. The Ramsar Convention's definition explicitly includes areas of marine water, the depth of which at low tide does not exceed 6 meters. Statement 2 is incorrect. Hydric soils are, by definition, deficient in oxygen due to being saturated with water for long periods. This leads to anaerobic conditions and slow decomposition. Statement 3 is incorrect. The dominant food chain in wetlands is the detritus pathway, based on the decomposition of dead organic matter (like macrophytes), not the grazing pathway.

Question 41

Statement-I: The criteria for identifying 'Wetlands of National Importance' under India's national program are aligned with the standards set by the Ramsar Convention.

Statement-II: The legal framework for the conservation and management of these identified wetlands is primarily derived from the Wildlife (Protection) Act, 1972.

Accepted Answer

Statement-I is correct but Statement-II is incorrect. Statement-I is correct. The criteria for identifying Wetlands of National Importance under the National Wetlands Conservation Programme (NWCP) are the same as those prescribed under the Ramsar Convention. Statement-II is incorrect. The primary legal framework governing wetlands is the Wetlands (Conservation and Management) Rules, which are notified under the Environment (Protection) Act, 1986, not the Wildlife (Protection) Act, 1972. The WPA, 1972, primarily focuses on protecting wildlife species and their habitats within designated protected areas like National Parks and Sanctuaries, which may include wetlands, but it is not the overarching legal framework for all wetlands in India.

Question 42

Consider the following pairs regarding the general distinctions between deep lakes and wetlands:
1. Dominant Producer : Macrophytes in Lakes
2. Thermal Stratification : Generally absent in Wetlands
3. Water Level Fluctuation : Large in Lakes
4. Trophic Status : Generally Oligotrophic in Wetlands
How many of the above pairs are correctly matched?

Accepted Answer

Only one pair. Pair 1 is incorrectly matched. The dominant producers in deep lakes are typically phytoplankton, whereas in wetlands, they are macrophytes (larger aquatic plants). Pair 2 is correctly matched. Due to their shallow nature, wetlands are generally well-mixed by wind and do not exhibit the strong thermal stratification found in deep lakes. Pair 3 is incorrectly matched. Water level fluctuations are typically large in wetlands (which can even be temporary) and relatively small in large, deep lakes. Pair 4 is incorrectly matched. Wetlands are highly productive and tend to be eutrophic, while deep, geologically young lakes are often oligotrophic (nutrient-poor).

Question 43

Consider the following statements regarding peatland ecosystems:

Statement-I: The drainage of peatlands for agricultural use often converts them from being carbon sinks into significant sources of greenhouse gases.
Statement-II: Introducing oxygen into the previously anaerobic, waterlogged soil halts all microbial activity, thereby preventing the decomposition of stored organic carbon.

Which one of the following is correct in respect of the above statements?

Accepted Answer

Statement-I is correct but Statement-II is incorrect. Statement-I is correct. Peatlands store vast amounts of carbon in waterlogged, anaerobic conditions. When drained, this carbon-rich organic matter is exposed to oxygen, leading to rapid decomposition and release of CO2, turning the ecosystem into a net source of greenhouse gases. Statement-II is incorrect. The introduction of oxygen does not halt microbial activity; it drastically accelerates it. Aerobic decomposition is much faster and more efficient than anaerobic decomposition, which is why the stored carbon is released so rapidly upon drainage. The statement inverts the actual scientific process.

Question 44

With reference to peatlands, consider the following statements:

1. Peatlands are a type of wetland characterized by the accumulation of partially decayed organic matter under waterlogged conditions.
2. As per the Ramsar Convention's definition of wetlands, they can be natural or artificial, but must contain only freshwater.
3. In India, peatlands are found not only in the Himalayan region but also in coastal areas.

How many of the statements given above are correct?

Accepted Answer

Only two. Statement 1 is correct: This is the fundamental definition of a peatland ecosystem. The waterlogged, low-oxygen environment slows down decomposition, leading to the accumulation of peat. Statement 2 is incorrect: The Ramsar Convention defines wetlands as areas with water that can be static or flowing, fresh, brackish, or salt, including areas of marine water. The restriction to 'only freshwater' is incorrect. Statement 3 is correct: While peatlands are well-known in the high-altitude regions of the Himalayas, they are also found in other parts of India, including the deltas and coastal areas of West Bengal (Sundarbans) and Kerala. Therefore, only two statements are correct.

Question 45

Consider the following statements regarding the legal framework for wetland conservation in India:
1. The Wetland (Conservation and Management) Rules are notified under the provisions of the Water (Prevention and Control of Pollution) Act, 1974.
2. Each State Wetland Authority is chaired by the Chief Minister of the respective state.
3. The Rules prohibit conversion for non-wetland uses including encroachment of any kind, but exclude aquaculture and salt pan development from this prohibition.
How many of the statements given above are correct?

Accepted Answer

None. Statement 1 is incorrect. The Wetland (Conservation and Management) Rules, 2017 have been notified under the provisions of the Environment (Protection) Act, 1986. Statement 2 is incorrect. The State Wetland Authority is headed by the State’s Environment Minister and not the Chief Minister. Statement 3 is incorrect. The rules prohibit a range of activities, including conversion for non-wetland uses, setting up of any industry, and disposal of construction and demolition waste. While certain pre-existing practices might be regulated differently, the statement presents a misleading exclusion; activities like aquaculture and salt pan development are regulated and not blanketly excluded from the prohibition on conversion.

Question 46

Consider the following statements:
Statement-I: Wetlands generally exhibit higher biological productivity and support greater biodiversity compared to deep-water lakes.
Statement-II: The dominant food chain in most wetland ecosystems is the grazing pathway, primarily driven by phytoplankton production.
Which one of the following is correct in respect of the above statements?

Accepted Answer

Statement-I is correct but Statement-II is incorrect.. Statement-I is correct. Wetlands, being transitional zones with shallow water, receive ample sunlight, leading to prolific growth of macrophytes and high nutrient availability. This supports a diverse range of species and high productivity. Statement-II is incorrect. The dominant food chain in wetlands is the detritus pathway, based on the decomposition of dead organic matter (like macrophytes). The grazing pathway, which is based on consuming live producers like phytoplankton, is more dominant in deep-water lakes. This inverts the actual ecological process.

Question 47

With reference to the criteria for identifying 'Wetlands of International Importance' under the Ramsar Convention, consider the following statements:
1. A wetland qualifies if it regularly supports 20,000 or more waterbirds.
2. The Convention imposes a legally binding framework on member countries to prevent any change in the ecological character of designated sites.
3. A wetland can be designated if it is an important source of food for fishes, or serves as a spawning ground or migration path.
Which of the statements given above are correct?

Accepted Answer

1 and 3 only. Statement 1 is correct. This is one of the specific criteria based on waterbirds for identifying a wetland for Ramsar designation. Statement 2 is incorrect. The Ramsar Convention is an intergovernmental treaty that provides a framework for national action and international cooperation, but it is not strictly legally binding in the sense of having punitive sanctions. It relies on the commitment of contracting parties to implement its guidelines. Statement 3 is correct. This is one of the specific criteria based on fish, recognizing the wetland's role in supporting fish stocks.

Question 48

With reference to the fauna of the Andaman and Nicobar Islands, consider the following statements:
1. The Dugong, a vulnerable marine mammal, is exclusively found in the seagrass beds surrounding the Nicobar Islands.
2. The Narcondam Hornbill is an endemic species found only on a single volcanic island and is known for its cavity-nesting behaviour.
3. The Giant Leatherback turtle has one of its largest mass-nesting sites in the world located on the islands of Great Nicobar.
How many of the statements given above are correct?

Accepted Answer

Only two. Statement 1 is incorrect. While Dugongs are found in the Andaman and Nicobar Islands, they are not exclusive to this region. They are also found in the Gulf of Mannar, Palk Bay, and the Gulf of Kutch in India, as well as in other parts of the Indo-Pacific. The word 'exclusively' makes the statement incorrect. Statement 2 is correct. The Narcondam Hornbill is endemic to the small volcanic island of Narcondam in the Andaman Sea. It is a cavity-nesting species. Statement 3 is correct. Galathea Bay on Great Nicobar Island is a globally significant nesting site for the Giant Leatherback turtle, the world's largest sea turtle.

Question 49

Consider the following statements regarding the impact of human activities on coral reef ecosystems:
Statement-I: A moderate increase in inorganic nutrients like nitrates and ammonia from coastal runoff directly triggers widespread coral bleaching.
Statement-II: Eutrophication enhances the population density of symbiotic zooxanthellae, which can increase the coral's susceptibility to other stressors like temperature changes.
Which one of the following is correct in respect of the above statements?

Accepted Answer

Statement-I is incorrect but Statement-II is correct. Statement-I is incorrect. An increase in ambient elemental nutrient concentrations (e.g., ammonia and nitrate) does not directly cause coral bleaching. In fact, it often leads to an increase in zooxanthellae densities, a phenomenon opposite to bleaching (which is the expulsion of zooxanthellae). Statement-II is correct. While not a direct cause of bleaching, eutrophication (nutrient enrichment) can cause secondary adverse effects. It increases zooxanthellae density, which can make the coral more vulnerable and lower its resistance to other stressors like thermal anomalies, thus increasing susceptibility to disease and bleaching under those conditions.

Question 50

With reference to the legal framework for protecting ecologically sensitive island territories in India, consider the following statements:
1. Under the Coastal Regulation Zone (CRZ-I) norms, construction of trans-harbour sea links and installation of weather radars are permissible activities.
2. The Island Protection Zone (IPZ) Notification is an entirely separate legal framework from the CRZ, with completely different sets of prohibitions.
3. The National Board for Wildlife is the sole authority for granting final clearance for any developmental project proposed within a notified National Park or Wildlife Sanctuary.
Which of the statements given above is/are correct?

Accepted Answer

1 only. Statement 1 is correct. The CRZ Notification, 2011, under CRZ-I, permits certain activities like the installation of weather radars by the IMD and the construction of trans-harbour sea links, subject to specific conditions, as these are considered vital infrastructure. Statement 2 is incorrect. The Island Protection Zone (IPZ) Notification, 2011, was issued for the protection of the Andaman & Nicobar and Lakshadweep islands. It is not an entirely separate framework but is based on the same principles as the CRZ notification, tailored for the specific geography of islands. Statement 3 is incorrect. The National Board for Wildlife (NBWL) plays a critical recommendatory role, but it is not the 'sole' authority for final clearance. The process involves recommendations from the State Board for Wildlife, the Standing Committee of the NBWL, and final approval or rejection often rests with the Ministry of Environment, Forest and Climate Change (MoEFCC), and in some cases, is subject to judicial review by the Supreme Court. The term 'sole authority' is an exaggeration.

Question 51

Statement-I: An increase in ambient nutrient concentrations, such as nitrates from agricultural runoff, directly triggers mass coral bleaching by causing the immediate expulsion of zooxanthellae.

Statement-II: Eutrophication in marine environments invariably leads to a decrease in the density of symbiotic algae within coral tissues, reducing their primary productivity.

Accepted Answer

Both Statement-I and Statement-II are incorrect.. Statement-I is incorrect. An increase in ambient elemental nutrient concentrations (e.g., ammonia and nitrate) initially increases zooxanthellae densities, rather than causing their immediate expulsion. While eutrophication can cause secondary adverse effects like lowering coral resistance, it does not directly trigger bleaching in this manner. Statement-II is also incorrect. As explained, initial stages of eutrophication can actually increase the density of symbiotic algae (zooxanthellae) in coral tissues, not decrease it.

Question 52

With reference to the factors causing coral reef bleaching, consider the following statements:
1. Rapid dilution of reef waters from storm-generated precipitation is a primary driver of widespread, ocean-basin scale bleaching events.
2. Exposure to elevated concentrations of chemical contaminants like herbicides and copper can induce localized zooxanthellae loss.
3. Tectonic uplift that results in the subaerial exposure of reef flats is a recognized cause of coral bleaching.
Which of the statements given above is/are correct?

Accepted Answer

2 and 3 only. Statement 1 is incorrect. While rapid freshwater dilution can cause bleaching, such events are typically rare, localized, and confined to small, nearshore areas, not widespread ocean-basin scale events. Statement 2 is correct. Xenobiotics, which include contaminants like copper (Cu), herbicides, and oil, can cause zooxanthellae loss (bleaching) when corals are exposed to elevated concentrations. Statement 3 is correct. Subaerial exposure, which is the sudden exposure of corals to the atmosphere due to events like extreme low tides or tectonic uplift, can induce bleaching.

Question 53

Consider the following statements regarding the legal and institutional framework for coral reef protection in India:
1. The National Coastal Zone Management Authority is a statutory body established under the Wild Life (Protection) Act, 1972.
2. Under the Coastal Regulation Zone Notification, coral reefs are classified as CRZ-I, permitting strategic projects like those of the Department of Atomic Energy.
3. The Wildlife Crime Control Bureau is empowered to enforce regulations concerning coastal land use and development in ecologically sensitive zones.
How many of the above statements are correct?

Accepted Answer

Only one. Statement 1 is incorrect. The National and State Coastal Zone Management Authorities (CZMAs) are constituted under the provisions of the Environment (Protection) Act, 1986, to implement the CRZ Notification, not the Wild Life (Protection) Act, 1972. Statement 2 is correct. Coral reefs are categorized as ecologically sensitive areas under CRZ-I. While new construction is generally prohibited, the notification allows for certain strategic projects, including those related to the Department of Atomic Energy. Statement 3 is incorrect. The Wildlife Crime Control Bureau (WCCB) is primarily concerned with combating organized wildlife crime under the Wild Life (Protection) Act, 1972. Enforcement of CRZ notifications is the mandate of the CZMAs and state governments under the Environment (Protection) Act, 1986. Therefore, only one statement is correct.

Question 54

With reference to the physiological adaptations of mangrove species, consider the following statements:
1. They exhibit viviparity, where seeds germinate on the parent plant itself before falling, as an adaptation to saline germination challenges.
2. Pneumatophores are specialized aerial roots that primarily function to absorb atmospheric moisture and nutrients.
3. Some species excrete excess salt through glands on their leaves, while others can block salt absorption at the root level.
How many of the above statements are correct?

Accepted Answer

Only two. Statement 1 is correct. Vivipary is a key adaptive mechanism in mangroves to overcome germination problems in saline water and tidal environments. Statement 2 is incorrect. Pneumatophores are respiratory roots that grow upwards from the mud to help the plant's root system obtain oxygen in anaerobic (oxygen-poor) soil conditions, not to absorb moisture or nutrients from the atmosphere. This is a functional inversion. Statement 3 is correct. Mangroves have two main strategies for dealing with salt: some are salt-excluders (blocking uptake at the roots) and some are salt-excreters (using glands on leaves).

Question 55

Consider the following two statements:
Statement-I: Mangrove ecosystems contribute significantly to coastal stabilization and the trapping of fine sediments.
Statement-II: The dense and complex root structures of mangroves, such as prop roots, accelerate water flow, which forces suspended particles to rapidly deposit within the forest.
Which one of the following is correct in respect of the above statements?

Accepted Answer

Statement-I is correct but Statement-II is incorrect. Statement-I is correct. Mangrove forests are well-known for their ability to stabilize coastlines, prevent erosion, and build up land by trapping sediments. Statement-II is incorrect. The dense root systems of mangroves act as a physical barrier that *slows down* or *impedes* water flow. This reduction in velocity allows suspended sediments to settle out and become deposited, not the acceleration of water flow. The statement inverts the physical process.

Question 56

Consider the following statements regarding the physiological adaptations of mangrove species:
1. Pneumatophores are specialized aerial roots that primarily function to excrete excess salt absorbed from the brackish water.
2. Vivipary, the germination of seeds while still attached to the parent plant, is an adaptation to ensure seedling survival in unstable, saline soil conditions.
3. The anoxic sediments in mangrove forests act as significant sinks for heavy metals, sequestering them from the overlying water column.
How many of the above statements are correct?

Accepted Answer

Only two. Statement 1 is incorrect. Pneumatophores, or 'air roots', are adaptations to overcome respiration problems in water-logged, anaerobic soil; they are not primarily for salt excretion. Salt management is handled by other mechanisms like secretion through leaf glands or exclusion at the roots. Statement 2 is correct. Vivipary is a reproductive strategy where the seed germinates on the parent tree, allowing the propagule to be better equipped for survival upon falling into the harsh, saline, and often unstable tidal environment. Statement 3 is correct. The fine, oxygen-poor sediments under mangroves effectively trap and immobilize heavy metals, acting as a natural filter and sink for these pollutants.

Question 57

Consider the following pairs regarding mangrove forests in India:
1. Largest single block of tidal holophytic mangroves : Sundarbans
2. High concentration of species and genetic diversity : Bhitarkanika
3. Scrubby, stunted growth forming discontinuous patches : Andaman & Nicobar Islands
How many of the pairs given above are correctly matched?

Accepted Answer

Only two pairs. Pair 1 is correctly matched. The Sundarbans in the Ganga-Brahmaputra delta constitute the largest single block of tidal mangroves globally. Pair 2 is correctly matched. The Bhitarkanika mangroves in Odisha are recognized as the second largest in India and are noted for their high species concentration and genetic diversity. Pair 3 is incorrectly matched. The description of 'scrubby, stunted growth' is characteristic of the mangroves found in arid regions like the Gulf of Kachchh in Gujarat. The mangroves of the Andaman & Nicobar Islands are known for being dense, diverse, and relatively undisturbed.

Question 58

Statement-I: Mangrove ecosystems are highly effective in stabilizing coastal shorelines and act as a bio-shield against tsunamis and storm surges.
Statement-II: The complex and dense network of prop roots, stilt roots, and pneumatophores in mangroves significantly slows down water flow, which enhances sediment deposition and dissipates wave energy.

Accepted Answer

Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I.. Statement-I is a well-established fact. Mangroves provide a crucial ecosystem service by protecting coastal communities from natural hazards. Statement-II accurately describes the mechanism behind this service. The intricate root structure of mangrove plants acts as a physical barrier, reducing the velocity and force of incoming water. This action not only dissipates wave energy but also encourages the settling of suspended sediments, which helps in building up and stabilizing the coastline. Therefore, Statement-II provides the direct and correct scientific explanation for the phenomenon described in Statement-I.

Question 59

Consider the following statements regarding the physiological adaptations of mangrove species:
1. Mangrove ecosystems primarily act as carbon sinks by sequestering atmospheric carbon, while simultaneously being significant sinks for methane gas.
2. To overcome germination challenges in saline water, mangroves exhibit viviparity, where seeds germinate on the parent tree before dispersal.
3. All mangrove species manage high salinity by actively secreting excess salt through specialized glands located on their leaves.
How many of the statements given above are correct?

Accepted Answer

Only one. Statement 1 is incorrect. While mangroves are significant carbon sinks, the anoxic (oxygen-poor) sediments lead to the production and release of methane, making them a source, not a sink, of this particular greenhouse gas. Statement 2 is correct. Viviparity is a key reproductive strategy where seeds germinate while still attached to the parent plant, which is an adaptation to the harsh saline environment. Statement 3 is incorrect. Salt management strategies vary. While some species are salt-secretors (using leaf glands), others are salt-excluders, blocking salt uptake at the root level.

Question 60

Consider the following statements:
Statement-I: Mangrove forests are highly effective in stabilizing coastal shorelines and enhancing sediment deposition in intertidal zones.
Statement-II: Mangrove species develop specialized root structures, such as pneumatophores, which grow upwards from the anaerobic mud to facilitate gaseous exchange.
Which one of the following is correct in respect of the above statements?

Accepted Answer

Both Statement-I and Statement-II are correct but Statement-II is NOT the correct explanation for Statement-I.. Statement-I is correct. The dense and complex root systems of mangroves, particularly prop and stilt roots, slow down water flow, causing suspended sediments to settle. This process, known as sediment trapping, helps stabilize coastlines. Statement-II is also correct. Pneumatophores are indeed specialized aerial roots that allow mangroves to obtain oxygen in waterlogged, anoxic soil. However, Statement-II does not explain Statement-I. The primary reason for sediment deposition (Statement-I) is the physical obstruction by the root network (like prop roots), not the respiratory function of pneumatophores.

Question 61

With reference to the distribution and characteristics of mangroves in India, consider the following statements:
1. The Sundarbans host the world's largest single block of tidal holophytic mangroves, characterized by species like Heritiera fomes.
2. In Gujarat, mangroves are typically of a scrubby, stunted type, but their condition is improving, particularly in the Kori creek region.
3. The mangrove vegetation in the Andaman & Nicobar Islands is sparse and degraded due to high anthropogenic pressure from aquaculture.
Which of the statements given above is/are correct?

Accepted Answer

1 and 2 only. Statement 1 is correct. The Sundarbans, located in the delta of the Ganges, Brahmaputra, and Meghna rivers, constitute the world's largest single block of tidal holophytic mangroves. The dominant species, Heritiera fomes (locally known as Sundari), gives the forest its name. Statement 2 is correct. Due to the arid climate and high salinity, mangroves in Gujarat, particularly in the Gulf of Kutch, are typically scrubby and stunted. However, conservation efforts have led to improvements in their condition, especially in the Kori creek region. Statement 3 is incorrect. The mangrove forests of the Andaman & Nicobar Islands are some of the most pristine and diverse in India. They are relatively undisturbed and dense, benefiting from low anthropogenic pressure, which is the opposite of the degradation described in the statement.

Question 62

With reference to the Clean Ganga Fund (CGF), consider the following statements:

1. It is a statutory fund established under the Environment (Protection) Act, 1986 to ensure mandatory contributions from polluting industries.
2. The Trust that operates the fund is headed by the Prime Minister of India, with its secretariat in the Prime Minister's Office.
3. The fund is designed to receive voluntary contributions from residents, NRIs, and PIOs, with provisions for tax benefits to donors.

How many of the above statements are correct?

Accepted Answer

Only one. Statement 1 is incorrect. The Clean Ganga Fund (CGF) is based on voluntary contributions and is not a statutory fund established under the EPA, 1986. It is managed as a trust. Statement 2 is incorrect. The Trust that operates the CGF is headed by the Finance Minister, not the Prime Minister. Its secretariat is set up in the Ministry of Water Resources, River Development and Ganga Rejuvenation. Statement 3 is correct. The CGF's objective is to channel voluntary contributions from residents, NRIs/PIOs, and others. It also provides for tax benefits for domestic donors, similar to the Swachch Bharat Kosh.

Question 63

Consider the following statements regarding river rejuvenation programs in India:

Statement-I: The 'Aviral Dhara' component of the Namami Gange programme primarily focuses on ensuring sustainable municipal sewage management and making industries achieve Zero Liquid Discharge.

Statement-II: 'Aviral Dhara' translates to 'unrestricted flow' and aims to restore the river's ecological flow by enforcing River Regulatory Zones and conserving wetlands.

Which one of the following is correct in respect of the above statements?

Accepted Answer

Statement-I is incorrect but Statement-II is correct. Statement-I is incorrect. It incorrectly describes the 'Aviral Dhara' component. The activities mentioned—sustainable municipal sewage management and achieving Zero Liquid Discharge for industries—are the primary objectives of the 'Nirmal Dhara' (clean flow) component, which deals with pollution abatement. Statement-II is correct. 'Aviral Dhara' literally means 'continuous' or 'unrestricted flow'. This component correctly focuses on maintaining the river's environmental flow through measures like enforcing River Regulatory Zones, promoting rational agricultural practices, and restoring wetlands, all of which contribute to the quantity and continuity of water in the river.

Question 64

With reference to the evolution of river cleaning programs in India, consider the following statements:

1. The Ganga Action Plan, launched in the 1980s, primarily focused on pollution abatement by intercepting and treating domestic sewage and industrial effluents.
2. The National Ganga River Basin Authority (NGRBA) marked a shift in approach by adopting a comprehensive river basin perspective for planning and management.
3. The 'Namami Gange' mission is an integrated conservation mission that consolidates previous efforts and plans for future actions.

Which of the statements given above are correct?

Accepted Answer

1, 2 and 3. Statement 1 is correct. The Ganga Action Plan (GAP), launched in 1986, had the main objective of pollution abatement by diverting and treating domestic sewage and industrial waste from identified polluting sources. Statement 2 is correct. The establishment of the National Ganga River Basin Authority (NGRBA) signified a major policy shift from a town-centric approach to an integrated and comprehensive river basin approach for the conservation of the Ganga. Statement 3 is correct. The 'Namami Gange' programme was launched as an Integrated Ganga Conservation Mission to consolidate existing efforts and plan future actions in a more holistic and coordinated manner, building upon the frameworks of earlier programs.

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