DAY – 18 (InstaTest-18): Insta 75 Days Revision Plan-2023: Topic – ENVIRONMENT & ECOLOGY, Subject-wise Test 14 , Textbook-wise Test 18 and October 2022 CA

Solution: B

Population

• A population is a group of people from the same species who live together in the same area.

Biological Community

• It means the different groups of people who live in the same area and depend on each other.
• A community is made up of all the different species that live and interact in the same area.
• A community is made up of all the living things in an area.
• Communities include places like a grove of pine trees, a coral reef, a cave, a valley, a lake, or a stream.

Solution: B

A trophic level is the group of organisms within an ecosystem which occupy the same level in a food chain. There are five main trophic levels within a food chain, each of which differs in its nutritional relationship with the primary energy source. The primary energy source in any ecosystem is the Sun (although there are exceptions in deep sea ecosystems).

The solar radiation from the Sun provides the input of energy which is used by primary producers, also known as autotrophs. Primary producers are usually plants and algae, which perform photosynthesis in order to manufacture their own food source. Primary producers make up the first trophic level.

The rest of the trophic levels are made up of consumers, also known as heterotrophs; heterotrophs cannot produce their own food, so must consume other organisms in order to acquire nutrition.

Solution: A

Grazing food chain

The consumers which start the food chain, utilizing the plant or plant part as their food, constitute the grazing food chain. This food chain begins from green plants at the base and the primary consumer is herbivore.

• For example, In terrestrial ecosystem, grass is eaten up by caterpillar, which is eaten by lizard and lizard is eaten by snake.
• In Aquatic ecosystem phytoplanktons (primary producers) is eaten by zoo planktons which is eaten by fishes and fishes are eaten by pelicans.

1. ii) Detritus food chain

The initial energy source for detritus food chain is the waste materials and dead organic matter from the grazing food chain.

Solution: B

Ecotopes are the smallest ecologically-distinct landscape features in a landscape mapping & classification system.

Ecotopes are relatively homogeneous, spatially-explicit landscape units that are useful for stratifying landscapes into ecologically distinct features for the measurement and mapping of landscape structure, function and change.

Like ecosystems, ecotopes are identified using criteria that depend on the specific application involved.  In the case of ecotopes these are criteria defined within a specific ecological mapping and classification system (e.g. AEM).

Just as ecosystems are defined by the interaction of biotic and abiotic components, ecotope classification should stratify landscapes based on a combination of both biotic and abiotic factors, including vegetation, soils, hydrology and other factors.

Solution: C

Ecological succession is the process by which natural communities replace (or “succeed”) one another over time. For example, when an old farm field in the midwestern U.S. is abandoned and left alone for many years, it gradually becomes a meadow, then a few bushes grow, and eventually, trees completely fill in the field, producing a forest.

Each plant community creates conditions that subsequently allow different plant communities to thrive. For example, early colonizers like grasses might add nutrients to the soil, whereas later ones like shrubs and trees might create cover and shade. Succession stops temporarily when a “climax” community forms; such communities remain in relative equilibrium until a disturbance restarts the succession process.

There are two major types of ecological succession: primary succession and secondary succession.

Primary succession happens when a new patch of land is created or exposed for the first time. This can happen, for example, when lava cools and creates new rocks, or when a glacier retreats and exposes rocks without any soil. During primary succession, organisms must start from scratch. First, lichens might attach themselves to rocks, and a few small plants able to live without much soil might appear. These are known as “pioneer species.”

Gradually, the decomposition of those plants contributes to soil formation, and more and larger plants begin to colonize the area. Eventually, enough soil forms and enough nutrients become available such that a climax community, like a forest, is formed. If the site is disturbed after this point, secondary succession occurs.

Secondary succession happens when a climax community or intermediate community is impacted by a disturbance. This restarts the cycle of succession, but not back to the beginning—soil and nutrients are still present.

Solution: D

Ecological Pyramid Importance

The ecological pyramid is important in a biological system and the reasons made sense underneath:

• An ecosystem pyramid gives thought to the dietary patterns of various living creatures.
• The ecological pyramids are the number of living creatures in an ecosystem.
• It gives a little clarity of how much energy moved to start with one trophic level and then onto the next in the biological system.
• It gives data about the biodiversity of a region.
• The ecological pyramid is framed based on the food-consumer relationship.
• If the food chain order is annihilated, the biological pyramid will be obliterated and the entire environment will be seriously harmed.
• It helps in keeping up with equilibrium and helps in checking the entire state of a biological ecosystem.

Solution: C

What is Biomagnification?

Biomagnification is a process or a way through which certain chemical compounds or toxins accumulate at higher trophic levels in a food chain. This is also known as biological magnification. Toxins, heavy metals, mercury, and other hazardous products are present in larger concentrations in the chemical compounds. As the concentration of these compounds increases and accumulates, they travel up the food chain. When tainted substances are ingested by different levels of organisms in a food chain, severe health risks develop.

What is Bioaccumulation?

Bioaccumulation refers to the process of harmful compounds such as pollution, pesticides, and other toxins being absorbed directly into the human body through the air, water, food, or skin. As this toxin accumulates in the human body, it raises the risk of chronic poisoning and other serious health problems.

Bioconcentration describes the accumulation of a water-borne chemical by an aquatic organism, whereas bioaccumulation covers the uptake from all environmental sources, e.g. water, food and sediment. The bioconcentration potential of a chemical, expressed as the ‘BCF’, is either predicted or measured.

Solution: B

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.

Certain microorganisms are capable of fixing atmospheric nitrogen into ammonium ions. These include free living nitrifying bacteria (e.g. aerobic Azotobacter and anaerobic Clostridium) and symbiotic nitrifying bacteria living in association with leguminous plants and symbiotic bacteria living in non-leguminous root nodule plants (e.g. Rhizobium) as well as blue green algae (e.g. Anabaena, Spirulina).

Ammonium ions can be directly taken up as a source of nitrogen by some plants, or are oxidized to nitrites or nitrates by two groups of specialised bacteria: Nitrosomonas bacteria promote transformation of ammonia into nitrite. Nitrite is then further transformed into nitrate by the bacteria Nitrobacter.

Solution: C

Competition & Predation

Predation is when one organism eats another organism to obtain nutrients. The organism that is eaten is called the prey. Examples of predation are owls that eat mice, and lions that eat gazelles. Competition is when individuals or populations compete for the same resource, and can occur within or between species. When organisms compete for a resource (such as food or building materials) it is called consumptive or exploitative competition. When they compete for territory, it is called interference competition. When they compete for new territory by arriving there first, it is called preemptive competition. An example is lions and hyenas that compete for prey.

Commensalism

Commensalism is a relationship in which one organism benefits while the other is neither helped nor harmed. Examples are barnacles that grow on whales and other marine animals. The whale gains no benefit from the barnacle, but the barnacles gain mobility, which helps them evade predators, and are exposed to more diverse feeding opportunities. There are four basic types of commensal relationships. Chemical commensalism occurs when one bacteria produces a chemical that sustains another bacteria. Inquilinism is when one organism lives in the nest, burrow, or dwelling place of another species. Metabiosis is commensalism in which one species is dependent on the other for survival. Phoresy is when one organism temporarily attaches to another organism for the purposes of transportation.

Mutualism

Mutualism is a relationship in which both species benefit. Mutualistic interaction patterns occur in three forms. Obligate mutualism is when one species cannot survive apart from the other. Diffusive mutualism is when one organism can live with more than one partner. Facultative mutualism is when one species can survive on its own under certain conditions. On top of these, mutualistic relationships have three general purposes. Trophic mutualism is exemplified in lichens, which consist of fungi and either algae or cyanobacteria. The fungi’s partners provide sugar from photosynthesis and the fungi provide nutrients from digesting rock. Defensive mutualism is when one organism provides protection from predators while the other provides food or shelter: an example is ants and aphids. Dispersive mutualism is when one species receives food in return for transporting the pollen of the other organism, which occurs between bees and flowers.

Solution: A

boreal forest

• Cold regions with high rainfall, strong seasonal climates with long winters and short summers are characterized by boreal coniferous forest.

This is characterised by evergreen plant species such as Spruce, fir and pine trees, etc and by animals such as the lynx, wolf, bear, red fox, porcupine, squirrel, and amphibians like Hyla, Rana, etc

• Boreal forest soils are characterized by thin podzols and are rather poor. Both because, the weathering of rocks proceeds slowly in cold environments and because the litter derived from conifer needle (leaf) is decomposed very slowly and is not rich in nutrients.
• These soils are acidic and are mineral deficient. This is due to movement of large amount of water through the soil, without a significant counter-upward movement of evaporation, essential soluble nutrients like calcium, nitrogen and potassium which are leached sometimes beyond the reach of roots. This process leaves no alkaline oriented cations to encounter the organic acids of the accumulating litter.

• The productivity and community stability of a boreal forest are lower than those of any other forest ecosystem.

Solution: A

Neuston:

• These are unattached organisms which live at the air water interface such as floating plants, etc.

E.g., beetles and back-swimmers.

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.

Nekton:

• This group contains animals which are swimmers.
• The nektons are relatively large and powerful as they have to overcome the water currents.
• The animals range in size from the swimming insects (about 2 mm long) to the largest animals, the blue whale.

Benthos:

• The benthic organisms are those found living in the bottom of the water mass.

• Practically every aquatic ecosystem contains well developed benthos.

Solution: C

A “red tide” is a common term used for a harmful algal bloom.

Harmful algal blooms, or HABs, occur when colonies of algae—plant-like organisms that live in the sea and freshwater—grow out of control while producing toxic or harmful effects on people, fish, shellfish, marine mammals, and birds. The human illnesses caused by HABs, though rare, can be debilitating or even fatal.

But not all algal blooms are harmful. Most blooms, in fact, are beneficial because the tiny plants are food for animals in the ocean. In fact, they are the major source of energy that fuels the ocean food web.

A small percentage of algae, however, produce powerful toxins that can kill fish, shellfish, mammals, and birds, and may directly or indirectly cause illness in people. HABs also include blooms of non-toxic species that have harmful effects on marine ecosystems. For example, when masses of algae die and decompose, the decaying process can deplete oxygen in the water, causing the water to become so low in oxygen that animals either leave the area or die.

Solution: C

Mangroves are the characteristic littoral plant formation of tropical and subtropical sheltered coastlines. Mangroves are trees and bushes growing below the high-water level of spring tides which exhibits remarkable capacity for salt water tolerance. – FAO.

Characteristics of mangroves

• They are basically evergreen land plants growing on sheltered shores, typically on tidal flats, deltas, estuaries, bays, creeks and the barrier islands.
• The best locations are where abundant silt is brought down by rivers or on the backshore of accreting sandy beaches.
• Their physiological adaptation to salinity stress and to water logged anaerobic mud is high.
• They require high solar radiation and have the ability to absorb fresh water from saline/brackish water.

• It produces pneumatophores (blind roots) to overcome respiration problem in the anaerobic soil conditions.

Solution: D

WHAT CAUSES BLEACHING? Change in ocean temperature Increased Ocean temperature caused by climate change is the leading cause of coral bleaching. Runoff and pollution Storm generated precipitation can rapidly dilute ocean water and runoff can carry pollutants — these can bleach near-shore corals. Overexposure to sunlight When temperatures are high, high solar irradiance contributes to bleaching in shallow-water corals. Extreme low tides Exposure to the air during extreme low tides can cause bleaching in shallow corals.

Solution: D

Ecotone

• An ecotone is a zone of junction or a transition area between two biomes (diverse ecosystems).
• Ecotone is the zone where two communities meet and integrate.
• For e.g. the mangrove forests represent an ecotone between marine and terrestrial ecosystem.
• Other examples are grassland (between forest and desert), estuary (between fresh water and salt water) and riverbank or marshland (between dry and wet).

Solution: B

About Senna spectabilis:

• Senna spectabilis is a deciduous tree native to tropical areas of America
• The thick foliage of the tree arrests the growth of other indigenous tree and grass species. Thus, it causes food shortages for the wildlife population, especially herbivores
• IUCN: Least Concern
• Invasion of Senna spectabilis is most severe in Wayanad Wildlife Sanctuary and nearby forests

About Wayanad Wildlife Sanctuary

• It is part of the Nilgiri Biosphere Reserve along with Mudumalai Wildlife Sanctuary, Bandipur National Park, Nagarhole National Park, Mukurthi National Park, and Silent Valley.
• It has the world’s largest recorded population of the Asiatic elephant
• River: Kabini and its three tributaries (Kabini is the tributary of the Kaveri rivers)

Solution: B

About Nitrate Radicals:

• Nitrate radical is an oxide of nitrogen that consists of three oxygen atoms bound to a nitrogen atom.
• Nitrogen oxides are reactive gases that regulate the formation of air pollutants, including ozone and PM 2.5 particles.
• Nitrate radicals will oxidize gas pollutants such as volatile organic compounds (VOCs), which will then generate ozone and secondary organic aerosol.
• Ozone is an air pollutant that affects human health and crop yield.
• Secondary organic aerosol is an important component of PM2.5

Solution: B

Solution: A

According to the “Global report on neglected tropical diseases 2023” report published on World NTD Day — January 30, 2023, by World Health Organization (WHO), Neglected Tropical Diseases (NTD) continue to disproportionately impact the most impoverished members of the international community, living in areas with inadequate water safety, sanitation and access to health care.

 About Neglected Tropical Diseases:

• NTDs are a group of 20 conditions mainly prevalent in tropical areas where people do not have access to clean water or safe ways to dispose of human waste.
• They are caused by various pathogens, including viruses, bacteria, parasites, fungi, and toxins.
• NTDs are most common among marginalized communities in the developing regions of Africa, Asia, and the Americas.

Key Findings of the report:

• 16 countries accounted for 80 per cent of the global NTD burden. Globally, nearly 1.65 billion people were estimated to require treatment for at least one NTD.
• The document also highlighted the tremendous effects COVID-19 had on community-based initiatives, access to healthcare facilities, and healthcare goods supply chains. As a result, between 2019 and 2020, 34 per cent fewer persons received treatment for NTDs.

Solution: D

About Namdapha National Park:

• Namdapha (named after a river originating in the park and it meets Noa-Dehing river (a tributary of the Brahmaputra)
• Location: It lies in close proximity to the Indo-Myanmar-China trijunction (in Arunachal Pradesh)
• It is the fourth largest national park in India after the Hemis National Park (Ladakh), Desert National Park (Rajasthan), and Gangotri National Park (Uttarakhand)
• It is also on the Tentative List of UNESCO World Heritage Sites in India and a biodiversity hotspot
• It is the only park in the World to have the four Feline species of big cat:- Tiger, Leopard, Snow Leopard, and Clouded Leopard
• Famous for:  Namdapha flying squirrel (Critically Endangered species) and Hoolock Gibbons (the only ‘ape’ species found in India)

Solution: B

• Hydra Market, the world’s largest and oldest darknet marketplace of illegal items and services, was seized and shut down by German authorities in coordination with U.S. law enforcement.

Hence, option (b) is correct.

• The darknet, or dark web, is the collection of websites hidden from normal search engines and web browsers, with users accessing it with browsers that hide their identities.
• Hydra Market, whose users were primarily in Russian-speaking countries, last year accounted for what is estimated to have been 80% of all darknet market-related cryptocurrency transactions, according to the Justice Department.
• Since 2015, Hydra Market has received about $5.2 billion in cryptocurrency for transactions on the site, reaping commissions worth millions of dollars on those sales, the DOJ said.
• Hydra Market enabled vendors of a wide range of drugs — including heroin, other opioids, cocaine, methamphetamine and LSD — to connect with customers of those narcotics, who could rate sellers on a five-star system, according to U.S. prosecutors.

Solution: A

Earth sets record for shortest day as it speeds up rotation

On June 29, 2022 the Earth completed one rotation in 1.59 milliseconds less than the standard 24 hours, marking the shortest day ever since scientists began measuring the rotation of the Earth using atomic clocks.

Some experts suggest that the shortened length of the day could be related to the ‘Chandler wobble’, a phenomenon that refers to the small deviation in the movement of Earth’s geographical poles.

Hence, Option (a) is correct.

The Chandler Wobble is a small variation in the rotation of the Earth on its axis. This wobble in Earth’s rotation occurs because the axis around which our planet rotates doesn’t quite line up with its actual geometric axis of symmetry, causing the rotational axis to keep trying to adjust.

Using the European Southern Observatory (ESO)’s Very Large Telescope in Chile, the researchers uncovered distinct sodium signatures in the atmosphere of WASP-96b, an exoplanet located nearly 1,000 light-years from Earth. WASP-96b is about 20 percent larger than Jupiter and has roughly the same mass as Saturn, but since it’s much closer to its host star than Saturn is to the Sun, its sweltering temperature drops it into the “hot Saturn” category.

Hence, option (b) is incorrect.

The ergosphere is an ellipsoidal region around a Kerr black hole in which the hole’s rotation drags the spacetime continuum round with it – a phenomenon known as the Lense-Thiring effect or frame dragging – so that frames of reference are not stationary with respect to the rest of the universe.

Hence, option (c) is incorrect.

Solution: D

Salt in the ocean comes from two sources: runoff from the land and openings in the seafloor.

Rocks on land are the major source of salts dissolved in seawater. Rainwater that falls on land is slightly acidic, so it erodes rocks. This releases ions that are carried away to streams and rivers that eventually feed into the ocean. Many of the dissolved ions are used by organisms in the ocean and are removed from the water. Others are not removed, so their concentrations increase over time.

Another source of salts in the ocean is hydrothermal fluids, which come from vents in the seafloor. Ocean water seeps into cracks in the seafloor and is heated by magma from the Earth’s core

Ocean salinity decreases from equator to pole. Polar region has least salinity due to less rate of evaporation and great influx of fresh water. Hence Statement 1 is incorrect.

Closed Ocean normally has highest salinity due to less intermix with surrounding water bodies. Mediterranean Sea is one of the best example. Hence Statement 2 is incorrect.

https://oceanservice.noaa.gov/facts/whysalty.html

Solution: B

Solution: D

Shale Gas can emerge as an important new source of energy in the country. India has several Shale formations which seem to hold Shale Gas and oil. The Shale Gas formations are spread over several sedimentary basins such as Cambay, Gondwana, Krishna-Godavari and Cauvery on-land. The Government has issued “Policy Guidelines for Exploration and Exploitation of Shale Gas and Oil by National Oil Companies under Nomination regime” on 14th October, 2013. Under this Policy, the right to exploration and exploitation of Shale Gas & Oil will lie with the NOCs holding Petroleum Exploration License (PEL)/Petroleum Mining Lease (PML) granted under the nomination regime.  As per policy guidelines, ONGC Ltd. and Oil India ltd had to carry out Shale Gas and Oil exploration in 50 and 5 blocks respectively for assessment under Phase-I. ONGC is carrying out Shale Gas and Oil exploration activities in Cambay, Cauvery, Krishna-Godavari and Assam and Arakan Basins. Oil India Ltd is carrying out Shale Gas and Oil exploration activities in Assam and Rajasthan basins.
It is estimated that a number of sedimentary basins (Gangetic plain, Gujarat, Rajasthan, Andhra Pradesh & other coastal areas) in India, including the hydrocarbon bearing ones – Cambay, Assam-Arakan, & Damodar – have large shale deposits. Various agencies have made different estimates of shale gas and oil in the Indian sedimentary basins.

187. ONGC: 187.5 TCF of shale gas in 5 basins (Cambay On-land, Ganga Valley, Assam & Assam Arakan, Krishna Godavari On-land & Cauvery On-land.

     ii. Central Mine Planning and Design Institute (CMPDI): 45 TCF of shale gas in 6 sub basins (Jharia, Bokaro, North Karanpura, South Karanpura, Raniganj & Sohagpur).

     iii. United States Geological Survey (USGS) has also estimated technically recoverable shale gas resources of 6.1 TCF in 3 basins (Cambay Onland, Krishna Godavari Onland & Cauvery On-land).

Answer. D) hard work, brotherhood out national unity

Hard work is a challenge that the author throws to the public in the very first line. The passage also highlights the importance of national unity and not be divided on the lines of religion etc. Hence D is the correct answer.

Answer. C) rule of the poor

The passage states that the poor are not bound in a strict sense to the government because of their lack of voice in the government. Hence C is the correct answer.

110% of SP = 616 (Rate of sales tax = 10%)

SP = 616*100/110 = 560

CP = 100*SP/100 + gain%

CP = 100*560/100+12 = 500 Rs

Answer: B) 166.66%

Explanation:

Let the cost price of 1-liter pure milk be Re.1, then

{6 liters (milk)  → C.P = Rs. 6

{ 2 liters (water) → C.P = Rs. 0

→CP = Rs.6 only

8 litre mixture  =>

SP =>  8 x 2 = Rs. 16

Profit % = [(16 – 6)/6]x100 = 1000/6 = 166.66%

Correct Answer: B) 16.67%

Solution:

Let Q income = 100

P income = 120

Q’s Income is 20 less than P (120)

We need to calculate 20 is what percent of 120

(20/120)*100 = 16.67

Answer: C) 1800

Explanation:

Least Cost Price = Rs. (200 * 8) = Rs. 1600.

Greatest Selling Price = Rs. (425 * 8) = Rs. 3400.

Required profit = Rs. (3400 – 1600) = Rs. 1800.