Ecology question bank

Question 1

3) Consider the following statements.
1. In the composition of living organisms, carbon constitutes the maximum share in the dry weight of organisms.
2. In the total quantity of global carbon, maximum percentage of carbon is found in the atmosphere.
Which of the above statements is/are correct?

Answer 1

1. F; water 1st followed by C
2. F; max in oceans

Question 2

6) Which of the following are the main constituents of Biogas?
1. Methane
2. Hydrogen
3. Carbon Dioxide
4. Nitrogen

Answer 2

Though it includes all of these gases, here it is asking ‘main’, so answer will be Methane and CO2

Question 3

9) Consider the following statements.
1. Most mammals regulate their body temperature similarly like humans do.
2. Like humans, plants also have mechanisms to maintain internal temperature.

3. Very small animals are rarely found in polar regions since thermoregulation is energetically expensive for these animals.
   Which of the above statements is/are correct?
   a) 1 only
   b) 1, 2
   c) 1, 3
   d) 1, 2, 3

Answer 3

C

Plants, on the other hand, do not have such mechanisms to maintain internal temperatures.
Thermoregulation is energetically expensive for many organisms. This is particularly true for small animals like shrews and humming birds. Heat loss or heat gain is a function of surface area. Since small animals have a larger surface area relative to their volume, they tend to lose body heat very fast when it is cold outside; then they have to expend much energy to generate body heat through metabolism. This is the main reason why very small animals are rarely found in polar regions.

Question 4

11) Consider the following statements regarding Temperate Deciduous Biome
1. They are found in areas with warm moist summers and cool winters.
2. Soils of temperate forests are podozolic and fairly deep.
3. The trees shed their leaves in the summer season.
Which of the above statements is/are correct?

Answer 4

Solution: b)
Temperate deciduous or temperate broad-leaf forests are a variety of temperate forest ‘dominated’ by trees that lose their leaves each year. They are found in areas with warm moist summers and cool winters. Soils of temperate forests are podozolic and fairly deep.
The trees shed their leaves in the cold season. This is an adaptation for protecting themselves against the winter snow and frost.

Question 5

13) Consider the following statements.
1. Sea weeds are potential indicators of pollution in aquatic ecosystem, particularly heavymetal pollution due to their ability to bind and accumulate metals strongly.
2. Products like agar-agar and iodine can be extracted from seaweeds.
3. Rotting seaweed releases highly toxic gas.

4. Seaweeds have no differentiation of true tissues such as roots, stems and leaves
5. They usually grow in deep waters

Which of the above statements is/are correct?

a) 1, 2, 4
b) 1, 3, 4, 5
c) 2, 3
d) 1, 2, 3, 4

Answer 5

Sea weeds are macroscopic algae, which mean they have no differentiation of true tissues such as roots, stems and leaves.
• They grow in, shallow coastal waters wherever sizable sub-strata is available.
• Seaweeds are important as food for humans, feed for animals, and fertilizer for plants.
• Seaweeds are used as a drug for goiter treatment, intestinal and stomach disorders.
• Products like agar-agar and alginates, iodine which are of commercial value, are extracted from seaweeds.
• By the biodegradation of seaweeds methane like economically important gases can be produced in large quantities.
• They are potential indicators of pollution in coastal ecosystem, particularly heavy metal pollution due to their ability to bind and accumulate metals strongly.
• Rotting seaweed is a potent source of hydrogen sulfide, a highly toxic gas.

Question 6

14) Consider the following statements regarding Phytoplankton.
1. Phytoplankton obtain the energy through the process of photosynthesis. 2. Phytoplankton depend on B Vitamins for survival. 3. They are not found in freshwater eco-systems.
Which of the above statements is/are correct?
a) 1 only
b) 1, 3
c) 1, 2
d) 1, 2, 3

Answer 6

Solution: c)

Phytoplankton are crucially dependent on minerals. These are primarily macronutrients such as nitrate, phosphate or silicic acid, whose availability is governed by the balance between the so-called biological pump and upwelling of deep, nutrient-rich waters.
Phytoplankton depend on B Vitamins for survival

They are found in all water systems, including marine or brackish or fresh.

Question 7

17) Which of the following lakes is not designated as Ramsar wetland sites in India? a) Harike Lake
b) Pulicat Lake c) Loktak Lake
d) Rudrasagar Lake
Solution: b)

Answer 7

B

Question 8

Seaweeds are potential natural fertilizers because
1. They are rich in soil nutrients and amino acids.
2. They are not susceptible to coastal pollution as they are found in deep waters.
Which of the above statements is/are correct?
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2

Answer 8

Solution: a)
Seaweeds contains all soil nutrients (0.3% N, 0.1% P, 1.0% K, plus a full range of trace elements) and amino acids. Its jelly like alginate content helps to bind soil crumbs together.
However, caution should be observed when collecting seaweed, particularly from areas that are liable to pollution, such as downriver (including estuaries) of industrial activities as seaweed is susceptible to contamination.

Question 9

Bleaching, or the paling of coral colour occurs due to
1. Fall in the concentration of photosynthetic pigments within the zooxanthellae.
2. Extreme low tides
3. Inflow of Inorganic Nutrients
4. Decline in the densities of zooxanthellae
Select the correct answer code:
a) 1, 2, 3
b) 1, 2, 4
c) 1, 4
d) 1, 2, 3, 4

Answer 9

D

Question 10

Consider the following statements.
1. Cold water corals, in general, have greater amount of zooxanthellae than warm water corals and does not build reef-like structures.
2. Cold-water corals differ from warm water corals because the former does not contain symbiotic algae for photosynthesis and grow more slowly.
Which of the above statements is/are incorrect?
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2

Answer 10

Solution: a)
Corals that inhabit the colder deep waters of continental shelves and offshore canyons, ranging from 50 to over 1000m depths lack zooxanthellae and may build reef-like structures or occur solitarily.
Cold-water corals are different from their warm-water counterparts because they do not contain symbiotic algae for photosynthesis and grow more slowly. Cold-water corals obtain all their energy from organic matter and zooplankton, which they catch from the currents drifting past.
Cold-water corals can be found over a wide range of latitudes, from tropical to Polar Regions, and from the shallow to the deep seas.

Question 11

Consider the following statements regarding Nitrogen pollution.

1. Since Nitrates cannot penetrate deep into the soil, they pollute only surface water and not groundwater.
2. Nitrous oxide is a greenhouse gas
3. Agriculture remains the largest contributor to nitrogen emissions.
4. Nitrogen particles make up the largest fraction of PM2.5
   Which of the above statements is/are correct?
   a) 2 only
   b) 1, 2
   c) 2, 3, 4
   d) 1, 2, 3, 4

Answer 11

C

Nitrates not only affect surface water but also pollute groundwater sources.
Nitrous oxide (N2O) gas should not be confused with nitric oxide (NO) or nitrogen dioxide (NO2). Neither nitric oxide nor nitrogen dioxide are greenhouse gases. Nitrous oxide is a greenhouse gas.
Nitrogen particles make up the largest fraction of PM2.5, the class of pollutants closely linked to cardiovascular and respiratory illness
Though agriculture remains the largest contributor to nitrogen emissions, the non-agricultural emissions of nitrogen oxides and nitrous oxide are growing rapidly, with sewage and fossil-fuel burning — for power, transport and industry — leading the trend.

Question 12

Consider the following statements regarding Fluorinated gases.
1. They are emitted through semiconductor manufacturing processes.
2. They have the least global warming potential of all gases.
Which of the above statements is/are correct?
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2

Answer 12

A

These are some of the most potent and longest lasting type of greenhouse gases emitted by human activities.

Question 13

Which of the following are the sources that add nitrogen oxides into the atmosphere?
1. Lightning stroke
2. Bacteria living in soil
3. Reaction of Ultraviolet radiation with ozone
Select the correct answer code:
a) 2 only
b) 1, 2
c) 2, 3
d) 1, 2, 3

Answer 13

B

Question 14

Which among the following greenhouse gases has the shortest atmospheric lifetime?

a) Nitrous oxide
b) Sulfur hexafluoride
c) Nitrogen trifluoride
d) Methane

Answer 14

D

CO2

Question 15

27) An ecotype is a population that
1. Play a specific functional ‘Keystone’ role in an ecosystem
2. Carries genes to successfully adapt to local environmental conditions
Select the correct answer code:
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2

Answer 15

Solution: b)
Statement 1 describes Keystone species.
An ecotype is a population that is adapted to local environmental conditions. The implication is that those individuals which were best adapted to the prevailing conditions left the most offspring.
Moreover, those more successful individuals carry genes that are partly responsible for their success in that environment. Thus, the adaptations of these ecotypes are based on the interactions of their own special sets of genes with their own environment.

Question 16

Consider the following statements regarding Eutrophication.
1. It leads to increase in the primary productivity of the water body.
2. It can occur only in the water bodies.
Which of the above statements is/are correct?
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2

Answer 16

A

Eutrophication, or hypertrophication, is when a body of water becomes overly enriched with minerals and nutrients which induce excessive growth of algae. This process may result in oxygen depletion of the water body. It leads to increase in the primary productivity of the water body or ‘bloom’ of phytoplankton.
Eutrophication can also occur outside water bodies. For example, soils can be eutrophic when they have high levels of nitrogen, phosphorous or other nutrients.

Question 17

The primary productivity of the tropical rain forest is lower compared to the temperate forests because of
1. Intense leaching of soil in tropical rain forests
2. Low microbial activity in tropical regions
Select the correct answer code:
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2

Answer 17

A

rainforests are also notable for replenishing the soil quickly with dead organic matter (e.g. leafs that fall from trees).

Question 18

Which of the following regions on earth qualify as biodiversity hotspots?
1. The biodiversity of the region is threatened.
2. Areas where multiple ecological niches occur
Select the correct answer code:
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2

Answer 18

Solution: a)
To qualify as a biodiversity hotspot, a region must meet two strict criteria:
• It must have at least 1,500 vascular plants as endemics — which is to say, it must have a high percentage of plant life found nowhere else on the planet. A hotspot, in other words, is irreplaceable.

Question 19

Which of the following plant micronutrients is associated with chlorophyll formation in plants?
1. Iron
2. Copper
3. Magnesium
Select the correct answer code:
a) 1, 2
b) 1, 3
c) 2, 3
d) 1, 2, 3

Answer 19

D

Magnesium forms a part of the chlorophyll molecule - essential in photosynthesis.
Iron is taken up in ferrous and ferric forms by plants. It acts as a catalyst in the production of chlorophyll.
Cu+2 (copper) can be absorbed through leaves. It becomes very toxic if too much applied. It is also a catalyst in chlorophyll formation.

Question 20

State the micro-organism (bacteria, fungi or virus) and mode of transmissions for following plant diseases

1. Citrus canker
2. Rust of Wheat
3. Yellow Vein mosaic of bhindi

Answer 20

1. bacteria; air
2. Fungi; air, seeds
3. Virus; insect

Question 21

Photoperiodism is a phenomenon related to

a) Mode of photosynthesis in plants
b) Flowering in plants
c) Both a and b
d) Neither a nor b

Answer 21

B

Photoperiodism is the physiological reaction of organisms to the length of day or night. It occurs in plants and animals.
• It has been observed that some plants require a periodic exposure to light to induce flowering. It is also seen that such plants are able to measure the duration of exposure to light.
• For example, some plants require the exposure to light for a period exceeding a well defined critical duration, while others must be exposed to light for a period less than this critical duration before the flowering is initiated in them.
• Together with temperature changes, photoperiod provokes changes in the colour of fur and feathers, migration, entry into hibernation, sexual behaviour etc. For e.g. the singing frequency of birds such as the canary depends on the photoperiod.

Question 22

Consider the following statements.
1. The highest number and high endemism of orchid species are found in Western Ghats.
2. Trade of wild orchid is banned globally.
3. Botanical Survey of India conducts census of orchids in India.
Which of the above statements is/are correct?

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

Answer 22

C

Botanical Survey of India conducts census of orchids in India.
• A State-wise distribution of orchid species point out that the Himalayas, North-East parts of the country and Western Ghats are the hot-spots of the beautiful plant species.
• While north-east India rank at the top in species concentration, the Western Ghats have high endemism of orchids.
• Entire orchid family is listed under appendix II of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) and hence any trade of wild orchid is banned globally.

Question 23

Consider the following statements. 1. The park was created to protect its keystone species, the Nilgiri tahr. 2. The park is characterised by montane grasslands and shrublands interspersed with sholas in a high-altitude area of high rainfall, near-freezing temperatures and high winds. 3. The park is a part of Nilgiri Biosphere Reserve. The above statements mainly refer to a) Mudumalai National Park b) Mukurthi National Park c) Silent Valley National Park d) Eravikulam National Park

Answer 23

B

Question 24

Consider the following statements about Tamil yeoman. 1. Tamil yeoman is the butterfly species endemic to Western Ghats which has been declared the state butterfly of Tamil Nadu. 2. Tamil Nadu became the first state in the country to declare a state butterfly. Which of the above statements is/are correct? a) 1 only b) 2 only c) Both 1 and 2
d) Neither 1 nor 2

Answer 24

A

Maharashtra was the first to declare Blue Mormon as its state butterfly, followed by Uttarakhand (Common peacock), Karnataka (Southern bird wings) and Kerala (Malabar banded peacock).

Question 25

44) Which of the following rivers flows through Kaziranga National Park?
1. Brahmaputra

2. Diphlu
3. Dharla
4. Mora Dhansiri
5. Rangpo
   Select the correct answer code:
   a) 1, 2, 3
   b) 1, 3, 4, 5
   c) 1, 2, 4
   d) 1, 2, 3, 4, 5

Answer 25

C

Kaziranga is crisscrossed by four main rivers — Brahmaputra, Diphlu, Mora Diphlu and Mora Dhansiri and has numerous small water bodies.

Question 26

Consider the following statements. 1. India is a temporary home to several migratory animals and birds like Amur Falcons, Bar-headed Geese, and Humpbacked Whales. 2. The Indian sub-continent is also part of Central Asian Flyway (CAF) that covers areas between the Arctic and Indian Oceans. 3. India had legally binding MoUs with the Convention on Migratory Species (CMS) on the conservation and management of Siberian Cranes and Marine Turtles.

Which of the above statements is/are correct? a) 1, 2 b) 1, 3 c) 2, 3 d) 1, 2, 3

Answer 26

A

India has signed a non-legally binding MOU with CMS on the conservation and management of Siberian Cranes (1998), Marine Turtles (2007), Dugongs (2008) and Raptors (2016).

India is a temporary home to several migratory animals and birds. The important among these include

Amur Falcons,

Bar-headed geese,

Black-necked cranes,

Marine turtles,

Dugongs,

Humpbacked Whales, etc.

The Indian sub-continent is also part of the major bird flyway network, i.e, the Central Asian Flyway (CAF) that covers areas between the Arctic and Indian Oceans.

Question 27

Which of the following are the Ozone depleting substances? 1. Hydrobromoflurocarbons (HBFCs) 2. Halons 3. Carbon tetrachloride 4. Methyl chloroform 5. Methyl bromide Select the correct answer code:

a) All except 3
b) All except 4
c) All except 5
d) All of the above

Answer 27

D

Question 28

Which of these ecosystems would sequester most carbon for a given unit of area?

a) Mature tropical forests
b) Saltmarsh
c) Grassland
d) Bare soil

Answer 28

B

Saltmarshes are one of the key coastal ‘blue carbon’ habitats, recognised for their ability to store carbon within above- and below-ground biomass and sediments.
Saltmarshes sequester carbon at a rate two to four times greater than that recorded for mature tropical forests

Question 29

Carbon Capture Utilization Storage (CCUS) is the process of

a) Generating carbon certificates from carbon-intensive activities and issuing them based on the carbon footprint associated with each such activity
b) Redistributing captured carbon from storage in the atmosphere to mitigate de-calcification in marine sources
c) Capturing waste carbon dioxide from large point sources and reusing it
d) Destroying atmospheric CO2 by way of electrostatic precipitators and storing the residue in specialized storages

Answer 29

C

Carbon capture utilization storage is the process of capturing waste carbon dioxide (CO2) from large point sources, such as fossil fuel power plants, and either transporting it to a storage site where it will not enter the atmosphere, normally an underground geological formation , or reusing it.
In Carbon Capture and Storage (CCS), emissions are forced into underground rocks at great cost and no economic benefit while CCUS aims at using CO2 emissions by exploiting the resource itself and creating new markets around it.

Question 30

Which of the following are the Geoengineering techniques designed to tackle the effects of climate change?

1. Adding large quantities of lime to the Ocean water to increase the amount of CO2 absorption by the oceans.
2. Floating thousands of tiny mirrors in space between Earth and the sun.
3. Using unmanned ships to increase above-ocean cloud cover by spraying sea water into the air.
4. Artificial trees that pull the CO2 from the atmosphere using plastic polymers.

Select the correct answer code: a) 1, 2, 3 b) 1, 3, 4 c) 1, 2, 4 d) 1, 2, 3, 4

Answer 30

D

Geoengineering schemes are projects designed to tackle the effects of climate change directly, usually by removing CO2 from the air or limiting the amount of sunlight reaching the planet’s surface.

The first category of scheme – those designed to remove CO2 from the air – include machines (sometimes called “artificial trees”) that pull the gas from the atmosphere using plastic polymers. Other proposals seek to increase the amount of CO2 absorbed by the oceans – for example by adding large quantities of lime to the water.

In the second category – schemes designed to reduce the amount of sunlight reaching Earth – proposals include firing sulphate aerosols into the stratosphere to reflect sunlight back to space; using unmanned ships to increase above-ocean cloud cover by spraying sea water into the air; painting the world’s roofs white to increase reflectivity; and even floating thousands of tiny mirrors in space between Earth and the sun.

Question 31

Which of the following statements best describes biotic potential?

a) It refers to the potential biomass of a population measured as dry weight per unit area.
b) It refers to the maximum reproductive capacity of an organism under optimum environmental conditions.
c) It refers to the possible functional roles a species can play in an ecosystem.
d) It refers to the minimum population of a species required to sustain a food web

Answer 31

B

Question 32

Consider the following statements. 1. States and Union Territories with more than 50 per cent of their land under forest cover can undertake compensatory afforestation in other states. 2. According to the Forest (Conservation) Act, 1980, each time forest land is diverted, the project proponent has to pay the state for the ecosystem services lost due to diverting forest land.
Which of the above statements is/are correct?

Answer 32

B

States and Union Territories with more than 75 per cent of their land under forest cover can undertake compensatory afforestation in other states.

Question 33

The Global Environment Facility (GEF) provides funding to assist developing countries in meeting the objectives of international environmental conventions. The GEF serves as a “financial mechanism” to which of these conventions?

1. Stockholm Convention on Persistent Organic Pollutants (POPs)
2. Minamata Convention on Mercury
3. Convention on Biological Diversity (CBD)
4. UN Convention to Combat Desertification (UNCCD)

Select the correct answer code: a) 1, 2 b) 1, 2, 3 c) 2, 3, 4 d) 1, 2, 3, 4

Answer 33

D

The GEF provides funding to assist developing countries in meeting the objectives of international environmental conventions. The GEF serves as a “financial mechanism” to five conventions: Convention on Biological Diversity (CBD), United Nations Framework Convention on Climate Change (UNFCCC), Stockholm Convention on Persistent Organic Pollutants (POPs), UN Convention to Combat Desertification (UNCCD), and Minamata Convention on Mercury.

Question 34

Consider the following statements regarding Green Climate Fund (GCF).
1. The Green Climate Fund (GCF) is a fund established within the framework of the UNFCCC.
2. The Fund’s investments can be in the form of grants only.
3. GCF has established a direct access modality so that national and sub-national organisations can receive funding directly, rather than only via international intermediaries.
Which of the above statements is/are correct?

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

Answer 34

C

The Green Climate Fund (GCF) is a global fund created to support the efforts of developing countries to respond to the challenge of climate change. GCF helps developing countries limit or reduce their greenhouse gas (GHG) emissions and adapt to climate change. It seeks to promote a paradigm shift to low-emission and climate-resilient development, taking into account the needs of nations that are particularly vulnerable to climate change impacts.
It was set up by the countries who are parties to the United Nations Framework Convention on Climate Change (UNFCCC) in 2010, as part of the Convention’s financial mechanism.
GCF’s activities are aligned with the priorities of developing countries through the principle of country ownership, and the Fund has established a direct access modality so that national and sub-national organisations can receive funding directly, rather than only via international intermediaries.
The Fund’s investments can be in the form of grants, loans, equity or guarantees

Question 35

Consider the following statements regarding International Union for Conservation of Nature (IUCN). 1. Its main aim is to mobilize the public in support of nature conservation. 2. It has observer and consultative status at the United Nations. 3. It was involved in establishing the World Wide Fund for Nature. Which of the above statements is/are correct? a) 2, 3 b) 1, 3 c) 1, 2 d) 2 only

Answer 35

A

The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education.
IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice, and through building partnerships.
IUCN has a membership of over 1400 governmental and non-governmental organizations. Its headquarters are in Gland, Switzerland.

IUCN has observer and consultative status at the United Nations and plays a role in the implementation of several international conventions on nature conservation and biodiversity. It was involved in establishing the World Wide Fund for Nature and the World Conservation Monitoring Centre.
IUCN was established in 1948. It was previously called the International Union for the Protection of Nature (1948–1956) and the World Conservation Union (1990–2008).

Question 36

The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for the assessment of climate change. Consider the following statements regarding Intergovernmental Panel on Climate Change.
1. Its membership is open to all member countries of the United Nations (UN).
2. It was established by the United Nations Framework Convention on Climate Change (UNFCCC).
3. Scientists from all over the world contribute to the work of the IPCC on a voluntary basis.
Which of the above statements is/are correct?
a) 1, 2
b) 1, 3
c) 2, 3
d) 1, 2, 3

Answer 36

B

As an intergovernmental body, membership of the IPCC is open to all member countries of the United Nations (UN) and WMO.
It was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) in 1988 to provide the world with a clear scientific view on the current state of knowledge in climate change and its potential environmental and socio-economic impacts

Question 37

Consider the following statements
1. Humification leads to accumulation of a dark colored amorphous substance called humus.
2. Humus is highly resistant to microbial action and undergoes decomposition at an extremely slow rate.
3. The humus is further degraded by some microbes and release of inorganic nutrients occurs by the process known as catabolism.
Which of the above statements is/are correct?

a) 1 only
b) 1, 2

c) 1, 3
d) 1, 2, 3

Answer 37

B

Detrivores (e.g., earthworm) break down detritus into smaller particles. This process is called fragmentation.

Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called as catabolism. It is important to note that all the above steps in decomposition operate simultaneously on the detritus.
• Humification and mineralization occur during decomposition in the soil. Humification leads to accumulation of a dark colored amorphous substance called humus that is highly resistant to microbial action and undergoes decomposition at an extremely slow rate. Being colloidal in nature it serves as a reservoir of nutrients. The humus is further degraded by some microbes and release of inorganic nutrients occurs by the process known as mineralization.

Question 38

Consider the following statements regarding life form in aquatic ecosystem.
1. Neuston: These are unattached organisms which live at the air water interface.
2. Nekton: These are organisms which remain attached to stems and leaves of rooted plants
4. Benthos: The benthic organisms are those found living in the bottom of the water mass.
Which of the above statements is/are correct?
a) 1, 3
b) 1, 2
c) 2, 3
d) 1, 2, 3

Answer 38

A

i) Neuston:
• These are unattached organisms which live at the air water interface such as floating plants, etc.
ii) Periphyton:
• These are organisms which remain attached to stems and leaves of rooted plants or substances emerging above the bottom mud such as sessile algae and their associated group of animals.
iii) Plankton:
• This group includes both microscopic plants like algae (phytoplankton) and animals like crustaceans and protozoans (zooplankton) found in all aquatic ecosystems, except certain swift moving waters.
iv) Nekton:
• This group contains animals which are swimmers.
• The nektons are relatively large and powerful as they have to overcome the water currents.
• The animal’s range in size from the swimming insects (about 2 mm long) to the largest animals, the blue whale.
v) Benthos:
• The benthic organisms are those found living in the bottom of the water mass.
• Practically every aquatic ecosystem contains well developed benthos.

Question 39

Consider the following statements regarding population interactions.
1. In competition, only one species benefits and the other is harmed.
2. The interaction where one species is benefitted and the other is neither benefitted nor harmed is called commensalism.
3. Example of commensalism is the interaction between sea anemone that has stinging tentacles and the clown fish.
Which of the above statements is/are correct?
a) 1, 2
b) 2, 3
c) 1, 3
d) 1, 2, 3

Answer 39

B

+ + Mutualism

– – Competition

+ – Predation/ parasitism

+ 0 commensalism

– 0 Amensalism

Example of commensalism is the interaction between sea anemone that has stinging tentacles and the
clown fish that lives among them. The fish gets protection from predators which stay away from the stinging
tentacles. The anemone does not appear to derive any benefit by hosting the clown fish.

Question 40

Consider the following statements regarding nitrous oxide.

1. Being a short-lived greenhouse gas, it substantially contributes to global warming.
2. When it reaches the stratosphere it reacts with ozone and depletes it, with an impact comparable to that of CFCs.
3. 2020 saw dip in nitrous oxide concentration in atmosphere and it reached below 300 ppb.

Which of the above statements is/are correct?

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

Answer 40

D

Nitrous oxide’s atmospheric concentration reached 333 parts per billion (ppb) in 2020, increasing at a rate of about 1 ppb annually. It is a major scavenger of stratospheric ozone, with an impact comparable to that of CFCs.
Being the third most important long-lived greenhouse gas, nitrous oxide also substantially contributes to global warming

Question 41

Kawal Tiger Reserve, recently seen in news is located in a) Kerala b) Telangana c) Karnataka d) Tamil Nadu

Answer 41

B

The Kawal Tiger Reserve, located in Telangana is going to host its first ever ‘Bird Walk’.
Kawal is home to a rich diversity in flora and fauna with more than 300 species of birds, and over 600 tree species with different forest compositions such as pure teak, bamboo with teak, pure bamboo.

Question 42

Consider the following statements.

1. As per State of Forests Report, 2021 Uttarakhand reported the maximum fires among all states.
2. State of Forests Report, 2021 acknowledged the link between climate change and forest fires.
3. The Union environment ministry supports the efforts of state governments in preventing and controlling forest fire by providing financial assistance under the centrally sponsored forest fire prevention and management scheme.
   Which of the above statements is/are correct?

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

Answer 42

C

Odisha reported the maximum fires among all states (51,968), followed by Madhya Pradesh (47,795) and Chhattisgarh (38,106).
SoFR, 2021 too acknowledged the link between climate change and forest fires, citing the global forest resources assessment 2020.

Question 43

Consider the following statements regarding Solar Radiation Modification (SRM).

1. It aims to address climate change by reflecting more sunlight back into space.
2. It allows more infrared radiation from Earth to escape, in order to reduce the Earth’s temperature.
3. It is highly considered as a substitute for reducing emissions, or removing atmospheric CO2.
   Which of the above statements is/are correct?
   a) 1 only
   b) 1, 2
   c) 1, 3
   d) 1, 2, 3

Answer 43

B

Solar Radiation Modification (SRM), also known as Solar Radiation Management, Radiation Modification Measures or Solar Geoengineering, would aim to address a symptom of climate change by reflecting more sunlight back into space, or by allowing more infrared radiation from Earth to escape, in order to reduce the Earth’s temperature. It includes numerous proposed methods which differ significantly. None are ready for deployment. Solar Radiation Modification could not be a substitute for reducing emissions, or removing atmospheric CO2.

Question 44

Which of the following statements about koalas is/are true?

1. They were recently classified as critically endangered after widespread bushfires, drought and land clearing destroyed much of their eucalyptus-rich habitat.
2. They are a relatively new species with evolutionary evidence of 5 million years only

Answer 44

1. F; classified as endangered
2. F; According to fossil records, Koala species have inhabited parts of Australia for at least 25 million years, a WWF report states.

Question 45

Consider the following statements regarding Root bridges.
1. Root bridges in India are located at Mawlynnong in Meghalaya.
2. Such bridges have been developed by Khasi villagers by weaving the roots of ficus trees.
Which of the above statements is/are correct?
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2

Answer 45

C

Question 46

CO2 injection technology is used to
1. Enhance oil recovery from ageing oil fields
2. Reduce the carbon content of vehicular emissions
3. Sequester atmospheric carbon for ocean basin storage
Which of the above statement(s) is/are correct?
a) 1 only
b) 1, 2
c) 1, 3
d) 1, 2, 3

Answer 46

A

Under it, CO2 gas is injected with residual oil in the ageing field in which total oil production has been declining.
It reduces its viscosity and makes it easier to displace oil from the rock pores. CO2 gas also swells oil, thereby pushing it towards the producing well for extraction.
CO2- Enhanced Oil Recovery (EOR) works most commonly by injecting CO2 into already developed oil fields where it mixes with and ‘releases’ the oil from the formation, thereby freeing it to move to production wells. CO2 that emerges with the oil is separated in above-ground facilities and re-injected into the formation.

CO2 EOR is an important component of U.S. oil production

Question 47

Consider the following statements.
1. The gharials are found in north Indian rivers of Ganga, Yamuna, Chambal and their tributaries.
2. In India, gharials were reintroduced into the Beas Conservation Reserve.
Which of the above statements is/are correct?
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2

Answer 47

C

Question 48

Consider the following statements regarding Carbonisation.
1. It involves pyrolysis of organic carbon to produce coke.
2. Wood does not undergo carbonisation.
3. A major advantage of industrial carbonisation is that no carbon monoxide emissions are involved.
Which of the above statements is/are correct?
a) 1 only
b) 1, 2
c) 1, 3
d) 1, 2, 3

Answer 48

A

Fossil fuels generally are the products of the carbonisation of vegetable matter. The term carbonisation is also applied to the pyrolysis of coal to produce coke. Carbonisation is also a stage in the charcoal making process, and is considered the most important step of all since it has such power to influence the whole process from the growing tree to the final distribution of charcoal to various sources. The gas produced by carbonisation has a high content of carbon monoxide which is poisonous when breathed.

Question 49

Consider the following statements regarding India State of Forest Report-2021.
1. According to the report, Forest and tree cover in the country has decreased since the last assessment in 2019.
2. In India the total forest and tree cover accounted for less than 30% of the geographical area of the country.
3. The accuracy in the current assessment of forest cover classification has been more than 90%.
Which of the above statements is/are correct?
a) 2 only
b) 1, 2
c) 2, 3
d) 1, 2, 3

Answer 49

C

The accuracy level achieved in the current assessment is significantly high. The accuracy of forest cover classification has been assessed 92.99%. The accuracy of classification between forest and non-forest classes has been assessed 95.79% against internationally accepted accuracy of classification of more than 85%.

Question 50

Which ofthe following are classified as long-lived greenhouse gases?
1. Carbon dioxide (CO2)
2. Methane (CH4)
3. Black carbon
4. Nitrous oxide (N2O)
Select the correct answer code:
a) 2, 4
b) 1, 2, 3
c) 1, 2, 4
d) 1, 2, 3, 4

Answer 50

C

Question 51

Which of the following sources produce sulphur dioxide emissions? 1. Volcanoes 2. Smelter ovens 3. Burning of coal and petroleum 4. Phytoplankton Select the correct answer code: a) 1, 2, 3 b) 1, 3

c) 1, 3, 4
d) 1, 2, 3, 4

Answer 51

D

Natural sources (volcanoes, fires, phytoplankton) produce sulphur dioxide, but burning sulphur-rich fossil fuels—primarily coal, oil, and petroleum—is the main source of the gas. Smelter ovens, which are used to concentrate metals found in ore, also produce it.