DAY – 51 (InstaTest-51): Insta 75 Days Revision Plan-2022: Topic – ENVIRONMENT & ECOLOGY and AGRICULTURE, Tests 30,31,32 , September 2021 CA

Solution: C

  The System of Air Quality and Weather Forecasting And Research (SAFAR) is a national initiative introduced by the Ministry of Earth Sciences (MoES) to measure the air quality of a metropolitan city, by measuring the overall pollution level and the location-specific air quality of the city.

  The system is indigenously developed by the Indian Institute of Tropical Meteorology (IITM), Pune and is operationalized by the India Meteorological Department (IMD).

• It has a giant true color LED display that gives out real-time air quality index on a 24×7 basis with color-coding (along with 72 hours advance forecast).

  The ultimate objective of the project is to increase awareness among the general public regarding the air quality in their city so that appropriate mitigation measures and systematic action can be taken up.

• It organizes awareness drive by educating the public (prompting self-mitigation), and
• It also helps the policy-makers to develop mitigation strategies keeping in mind the nation’s economic development.

SAFAR is an integral part of India’s first Air Quality Early Warning System operational in Delhi.

• It monitors all weather parameters like temperature, rainfall, humidity, wind speed, and wind direction, UV radiation, and solar radiation.
• Pollutants monitored: PM2.5, PM10, Ozone, Carbon Monoxide (CO), Nitrogen Oxides (NOx), Sulfur Dioxide (SO2), Benzene, Toluene, Xylene, and Mercury.

Solution: A

Phytoremediation

• Phytoremediation is use of plants to remove contaminants from soil and water .

Types

• Phytoextraction / phytoaccumulation is the process by which plants accumulate contaminants into the roots and above ground shoots or leaves.
• Phyto transformation or phytodegradation refers to the uptake of organic contaminants from soil, sediments, or water and their transformation to more stable, less toxic, less mobile form.
• Phyto stabilization is a technique in which plants reduce the mobility and migration of contaminated soil. Leachable constituents are adsorbed and bound into the plant structure so that they form unstable mass of plant from which the contaminants will not re-enter the environment.
• Phytodegradation or rhizodegradation is the breakdown of contaminants through the activity existing in the rhizosphere. This activity is due to the presence of proteins and enzymes produced by the plants or by soil organisms such as bacteria, yeast, and fungi.
• Rhizofiltration is a water remediation technique that involves the uptake of contaminants by plant roots. Rhizofiltration is used to reduce contamination in natural wetlands and estuary areas.

Solution: B

Pollutants are the materials or factors, which cause adverse effect on the natural quality of any component of the environment.

Classifications

(i) According to the form in which they persist after release into the environment.

• Primary pollutants: These persist in the form in which they are added to the environment e.g. DDT, plastic.
• Secondary Pollutants: These are formed by interaction among the primary pollutants.

• For example, peroxyacetyl nitrate (PAN) is formed by the interaction of nitrogen oxides and hydrocarbons.

(ii) According to their existence in nature.

• Quantitative Pollutants: These occur in nature and become pollutant when their concentration reaches beyond a threshold level. E.g. carbon dioxide, nitrogen oxide.
• Qualitative Pollutants: These do not occur in nature and are man-made. E.g. fungicides, herbicides, DDT etc.

(iii) According to their nature of disposal.

• Biodegradable Pollutants: Waste products, which are

by microbial action. E.g. sewage.

• Non-biodegradable Pollutants: Pollutants, which are not decomposed by microbial action. E.g. plastics, glass, DDT, salts of heavy metals, radioactive substances etc.,)

Solution: B

Fly Ash

• Ash is produced whenever combustion of solid material takes place.
• Fly ash is one such residue which rises with the gases into the atmosphere. Fly ash is a very fine powder and tends to travel far in the air.

The ash which does not rise is termed as bottom ash.

• Nearly 73% of India’s total installed power generation capacity is thermal, of which 90% is coal-based generation, with diesel, wind, gas, and steam making up the rest.

Composition

1. Aluminium silicate (in large amounts)
2. Silicon dioxide (SiO2) and
3. Calcium oxide (CaO).

• Fly ash particles are oxide rich and consist of silica, alumina, oxides of iron, calcium, and magnesium and toxic heavy metals like lead, arsenic, cobalt, and copper.

Solution: B

Tundra means a “barren land” since they are found where environmental conditions are very severe. There are two types of tundra- arctic and alpine.

• Distribution: Arctic tundra extends as a continuous belt below the polar ice cap and above the tree line in the northern hemisphere.

It occupies the northern fringe of Canada, Alaska, European Russia, Siberia and island group of Arctic Ocean. On the south pole, tundra is very small since most of it is covered by ocean.

Alpine tundra occurs at high mountains above the with respect to Arctic mountains are found at all latitudes therefore alpine tundra shows day and night temperature variations.

• Flora and fauna: Typical vegetation of arctic tundra is cotton grass, sedges, dwarf heath, willows, birches and lichens. Animals of tundra are reindeer, musk ox, arctic hare, caribous, lemmings and squirrel.

Most of them have long life e.g., arctic willow has a life span of 150 to 300 years. They are protected from chillness by the presence of thick cuticle and epidermal hair. Mammals of the tundra region have large body size, small tail and small ear to avoid the loss of heat from the surface. The body is covered with fur for insulation. Insects have short life cycles which are completed during favorable period of the year.

Solution: B

The sulphur reservoir is in the soil and sediments where it is locked in organic (coal, oil and peat) and inorganic deposits (pyrite rock and sulphur rock) in the form of sulphates, sulphides and organic sulphur. It is released by weathering of rocks, erosional runoff and decomposition of organic matter and is carried to terrestrial and aquatic ecosystems in salt solution.

The sulphur cycle is mostly sedimentary except two of its compounds hydrogen sulphide (H2S) and sulphur dioxide (SO2) add a gaseous component to its normal sedimentary cycle.

Sulphur enters the atmosphere from several sources like volcanic eruptions, combustion of fossil fuels, from surface of ocean and from gases released by decomposition. Atmospheric hydrogen sulphide also gets oxidised into sulphur dioxide. Atmospheric sulphur dioxide is carried back to the earth after being dissolved in rainwater as weak sulphuric acid.

Whatever the source, sulphur in the form of sulphates is take up by plants and incorporated through a series of metabolic processes into sulphur bearing amino acid which is incorporated in the proteins of autotroph tissues. It then passes through the grazing food chain. Sulphur bound in living organism is carried back to the soil, to the bottom of ponds and lakes and seas through excretion and decomposition of dead organic material.

Solution: C

The steps of trophic levels expressed in a diagrammatic way are referred as ecological pyramids. The food producer forms the base of the pyramid and the top carnivore forms the tip. Other consumer trophic levels are in between. The pyramid consists of a number of horizontal bars depicting specific trophic levels which are arranged sequentially from primary producer level through herbivore, carnivore onwards. The length of each bar represents the total number of individuals at each trophic level in an ecosystem. The number, biomass and energy of organisms gradually decrease with each step from the producer level to the consumer level and the diagrammatic representation assumes a pyramid shape.

The ecological pyramids are of three categories.

1. Pyramid of numbers,
2. Pyramid of biomass, and
3. Pyramid of energy or productivity.

Solution: A

A niche is the unique functional role or place of a species in an ecosystem. It is a description of all the biological, physical and chemical factors that a species needs to survive, stay healthy and reproduce.

A niche is unique for a species, which means no two species have exact identical niches.

Niche plays an important role in conservation of organisms. If we have to conserve species in its native habitat, we should have knowledge about the niche requirements of the species and should ensure that all requirements of its niche are fulfilled.

Types of Niche

1. Habitat niche – where it lives
2. Food niche – what is eats or decomposes &what species it competes with
3. Reproductive niche – how and when it reproduces.
4. Physical & chemical niche – temperature, land shape, land slope, humidity & other requirement.

Solution: C

Micro consumers – Saprotrophs (decomposers or osmotrophs)

• They are bacteria and fungi which obtain energy and nutrients by decomposing dead organic substances (detritus) of plant and animal origin.
• The products of decomposition such as inorganic nutrients which are released in the ecosystem are reused by producers and thus recycled.

• Earthworm and certain soil organisms (such as nematodes, and arthropods) are detritus feeders and help in the decomposition of organic matter and are called detrivores.

Solution: C

Pomology (from Latin pomum, “fruit,” + -logy) is a branch of botany that studies fruit and its cultivation.

The term fruticulture—introduced from Romance languages (all of whose incarnations of the term descend from Latin fructus and cultura)—is also used.

Olericulture is the science of vegetable growing, dealing with the culture of non-woody (herbaceous) plants for food.

Olericulture is the production of plants for use of the edible parts.

Apiculture is the scientific method of rearing honeybees. The word ‘apiculture‘ comes from the Latin word ‘apis’ meaning bee. So, apiculture or beekeeping is the care and management of honey bees for the production of honey and wax.

Solution: B

Critical Wildlife Habitats (CWH)

• The Critical Wildlife Habitats (CWH) have been envisaged in Forest Rights Act, 2006.
• CWH are defined under the act as the “areas of national parks and sanctuaries where it has been specifically and clearly established, case by case, on the basis of scientific and objective criteria, that such areas are required to be kept as inviolate for the purposes of wildlife conservation”
• ‘Inviolate’ is a general term used to indicate no human settlement and usage.
• MoTA is the nodal authority for FRA.
• But the FRA identifies MoEF&CC as the agency to notify the guidelines.

Solution: D

The Nitrogen Cycle

Nitrogen is an essential constituent of protein and is a basic building block of all living tissue. It constitutes nearly 16% by weight of all the proteins.

There is an inexhaustible supply of nitrogen in the atmosphere but the elemental form cannot be used directly by most of the living organisms. Nitrogen needs to be ‘fixed’, that is, converted to ammonia, nitrites or nitrates, before it can be taken up by plants. Nitrogen fixation on earth is accomplished in three different ways:

(i) By microorganisms (bacteria and blue-green algae)

(ii) By man using industrial processes (fertilizer factories) and

(iii) To a limited extent by atmospheric phenomenon such as thunder and lighting

Solution: A

Dissolved oxygen:

• In aquatic ecosystems oxygen is dissolved in water, where its concentration varies constantly depending on factors that influence the input and output of oxygen in water.
• In fresh water the average concentration of dissolved oxygen is 0.0010 per cent (also expressed as 10 parts per million or 10 ppm) by weight, which is 150 times lower than the concentration of oxygen in an equivalent volume of air.
• Oxygen enters the aquatic ecosystem through the air water interface and by the photosynthetic activities of aquatic plants.
• Therefore, the quantity of dissolved oxygen present in an ecosystem depends on the rate at which the aforesaid two processes occur.
• Dissolved oxygen escapes the water body through air water interface and through respiration of organisms (fish, decomposers, zooplanktons, etc).
• The amount of dissolved oxygen retained in water is also influenced by temperature. Oxygen is less soluble in warm water.

Warm water also enhances decomposer activity. Therefore, increasing the temperature of a waterbody increases the rate at which oxygen is depleted from water.

• When the dissolved oxygen level falls below 3-5 ppm, many aquatic organisms are likely to die.

Solution: D

Causes of climate change

The causes of climate change can be divided into two categories – Natural and man made

Natural causes

There are a number of natural factors responsible for climate change. Some of the important factors are continental drift, volcanoes, ocean currents and the earth’s tilt.

• Continental drift

The continents we see today were formed when the landmass began gradually drifting apart, millions of years back. This drift changed the position of water bodies of the landmass and the flow of ocean currents and winds. These changes affect the climate. This drift of the continents continues even today.

• Volcanoes

When a volcano erupts it throws out large volumes of sulphur dioxide (SO₂), water vapour, dust, and ash into the atmosphere. Although the volcanic activity may last only a few days, yet the large volumes of gases and ash can influence climatic patterns for years. The gases and dust particles partially block the incoming rays of the sun, leading to cooling.

• The earth’s tilt

The earth is tilted at an angle of 23.5° to the perpendicular plane of its orbital path. Changes in the tilt of the earth affect the severity of the seasons. More tilt means warmer summers and colder winters; less tilt means cooler summers and milder winters.

• Ocean currents

The oceans are a major component of the climate system. They cover about 71% of the Earth. The oceans absorb the sun’s radiation about twice as much as the atmosphere

Solution: C

Ozone is a form of oxygen. But unlike oxygen, ozone is a poisonous gas.

Each ozone molecule is made of three oxygen atoms, so its chemical formula is 0₃. Ozone is formed when ultraviolet radiation causes oxygen molecules (0₂) in the upper layers of the atmosphere to split apart. If a freed oxygen atom (O) bumps into an oxygen molecule (0₂), the three oxygen atoms re-form as ozone (0₃ ).

Good and bad ozone

In the stratosphere (the layer that is about 15 – 50 kms above the earth’s surface), where ozone exists naturally, it prevents the sun’s ultraviolet rays from reaching the earth and thereby protects life.

In the atmospheric layer closest to the earth’s surface, due to pollution by vehicles, nitrogen oxides and Hydrocarbons levels increase. In the presence of sunlight, these chemicals form ozone.  This ozone can cause health problems like coughing, throat irritation, aggravation of asthma, bronchitis etc. It can also damage crops. While ozone in the stratosphere benefits life on Earth by blocking ultraviolet radiation from the Sun, ozone in the lower atmosphere can trigger health problems.

What is ozone depletion?

Chlorofluorocarbons (CFCs) are the primary Ozone depleting chemicals. They are used as refrigerants in refrigerators, air conditioners etc. They contain Chlorine.

Ozone depletion process

• Step 1 : The CFCs generated as a result of human activities reach the ozone layer in the atmosphere
• Step  2 : The UV radiation from the sun breaks the CFCs and releases Chlorine
• Step 3 : The Chlorine atoms breaks the ozone molecule and thereby ozone depletion.

Solution:A

Solution:

• The End of History and the Last Man is a 1992 book of political philosophy by American political scientist Francis Fukuyama which argues that with the ascendancy of Western liberal democracy—which occurred after the Cold War (1945–1991) and the dissolution of the Soviet Union (1991)—humanity has reached “not just … the passing of a particular period of post-war history, but the end of history as such: That is, the end-point of mankind’s ideological evolution and the universalization of Western liberal democracy as the final form of human government.”

Solution: A

Solution:

Solution: B

Solution:

• Indonesia’s Mount Merapi continued to erupt Friday, forcing authorities to halt tourism and mining activities on the slopes of the country’s most active volcano.

• The volcano on the densely populated island of Java unleashed clouds of hot ash shortly before midnight Wednesday into early morning Thursday and fast-moving pyroclastic flows — a mixture of rock, lava and gas — traveled up to 5 kilometers (3.1 miles) down its slopes. It was Mount Merapi’s biggest lava flow since authorities raised its danger level in November 2020, said Hanik Humaida, the head of Yogyakarta’s Volcanology and Geological Hazard Mitigation Center.

Solution: D

Solution:

• E-100 pilot project were launched at Pune city by Public Sector Oil Marketing Companies (OMCs) .With a view to enhance fuel choice and facilitate sale of E-100 fuel, MoP&NG permitted the direct sale of Bioethanol (E100) by an oil company for use as standalone fuel or blending with motor spirit, for compatible automobiles to all consumers, in accordance with the standards specified by the Bureau of Indian Standards.

• The Notified National Policy on Biofuels – 2018, provided an indicative target of blending 20% ethanol in petrol by 2030. Government has undertaken several supply and demand side interventions since 2014 which has enabled improvement in ethanol blending from average 1.53% during Ethanol Supply Year (ESY) 2013-14 to 7.93% during ongoing ESY 2020-21 as on July 12, 2021.

Solution: C

Solution:

• Department Science and Technology (DST), Government of India, has developed the novel hybrid technology called SWASTIIK’ that involves boiling of a liquid as a result of pressure reduction (cavitation) and also uses natural oils having antimicrobial properties. This technology can eliminate harmful bacteria, including antimicrobial-resistant bacteria, economically. It not only integrates Indian traditional knowledge of Ayurveda for complete disinfection of water but also may offer possible health benefits of natural oils.

• Novel strategy of SWASTIIK (Safe Water and Sustainable Technology Initiative from Indian Knowledgebase) can have significant benefits in terms of providing SAFE WATER and also possible health benefits that can also boost immunity, an important aspect as underlined in the current COVID-19 era.

Solution: A

Solution: The Commission is a statutory authority.  The Commission will supersede bodies such as the central and state pollution control boards of Delhi, Punjab, Haryana, UP and Rajasthan.  It will have the powers to issue directions to these state governments on issues pertaining to air pollution.  Chaired by a government official of the rank of Secretary or Chief Secretary.

Solution: B

Solution: AmbiTag is a USB-shaped device that continuously records the temperature of its immediate surroundings from -40℃ to 80℃ in any time zone for a full 90 days on a single charge. Most of the similar devices available in the international market record data only for a duration of 30 – 60 days.AmbiTag is one of the best devices presently available in the international market.

Solution: A

Solution: Importers will have to ensure that imported goods meet the prescribed ‘rules of origin’ provisions for availing concessional rate of customs duty under Free Trade Agreements (FTAs).

Solution: D

Solution: B

Solution: They are four types of Black holes Stellar, Intermediate, Supermassive & Miniature

Answer : a

Sol. LCM of 10, 15, 21 and 28 = 420 , Largest number of 4 – digits = 9999

Now, (9999/420) = 23 ´ (339/420) \ Remainder = 339

\ Four – digit number divisible by 10, 15, 21 and 28 = 9999 – 339 = 9660

Also, k = 10 – 4 = 15 – 9 = 21 – 15, 28 – 22 = 6

\ Required number = ( 9660 – k )    = ( 9660 – 6 )  = 9654

Sol. (d) Let the numbers be 21 a and 21b, where a and b are coprimes.

Then, 21a x 21 b = (21 X 4641) , ab = 221

Two coprimes with product 221 are 13 and 17.

.: Required number = (21 x 13, 21 x 17) = (273,357)

Answer : a

Sol: Since the given number is divisible by 5, so 0 or 5 must come in place of #. But, a number ending with 5 is never divisible by 8. So, 0 will replace #. Now, the number formed by the last three digits is 4@0, which becomes divisible by 8, if @ is replaced by 4. Hence, digits in place of @ and # are 4 and 0 respectively.

Answer : a

Sol. If the number is divisible by 5 and 11 it must be divisible by 55. The numbers are less than 660. Hence, dividing 659 by 55 gives the number of multiples of 55 = 11 (ignoring fraction part).The 11 multiples of 55 which are less than 560, but of these 11 multiples some can be multiples of 3. The numbers of such, multiples is the quotient of 11 by 3. Quotient of 113=3113=3. Out of 11 multiples of 55, 3 are multiples of 3. Hence, numbers less than 660 and divisible by 5 and 11 but not by 3=11−3=8