test 6 solutions

INSIGHTS MOCK TEST 2015 TEST 6 SOLUTIONS

http://insightsonindia.com INSIGHTS Page 1

1. Solution: a)

Formation of coral reefs depends on temperature conditions, and not the meeting of warm

or cold currents.

Mangroves exist near coasts, so no cold and warm currents can meet there.

Sea grass is also found in shallow areas where the meeting of cold and warm currents is not

possible.

2. Solution: c)

Mechanism of tropical cyclones

Heating of ocean water creates a low pressure area to fill which wind from several high

pressure areas converge at high speeds. Due to the presence of coriolis force, they start

circulating around the low pressure zone.

The evaporated moisture from the ocean's low pressure area condenses above in the form of

cumulonimbus clouds. This latent heat of condensation from the moisture feeds more heat

to the cyclone and intensifies it.

On reaching the land, the cyclone dissipates as its moisture supply is cut off.

Extra-tropical cyclones

Formed in mid and high latitudes, beyond the tropics

Forms along polar fronts - Derives its energy from a meeting and circulation of

warm and cold air fronts

Mechanism

Initially the front is stationary. Then, Cold air blows from the North of the front; and warm

air blows from the south of the front.

When the pressure drops along the front, warm air moves northwards and cold air

southwards. Due to this movement across the front, an anti-clockwise cyclonic circulation

starts. This leads to the formation of the well developed extra-tropical cyclone with a warm

and cold front.

3. Solutions: c)

The Rh antigen similar to one present in Rhesus monkeys (hence Rh), is also observed on the

surface of RBCs of majority (nearly 80 per cent) of humans. Such individuals are called Rh

positive (Rh+ve) and those in whom this antigen is absent are called Rh negative (Rh-ve).

An Rh-ve person, if exposed to Rh+ve blood, will form specific antibodies against the Rh

antigens. Therefore, Rh group should also be matched before transfusions. A special case of



Rh incompatibility (mismatching) has been observed between the Rh-ve blood of a pregnant

mother with Rh+ve blood of the foetus. Rh antigens of the foetus do not get exposed to the

Rh-ve blood of the mother in the first pregnancy as the two bloods are well separated by the

placenta. However, during the delivery of the first child, there is a possibility of exposure of

the maternal blood to small amounts of the Rh+ve blood from the foetus. In such cases, the

mother starts preparing antibodies against Rh antigen in her blood. In case of her

subsequent pregnancies, the Rh antibodies from the mother (Rh-ve) can leak into the blood

of the foetus (Rh+ve) and destroy the foetal RBCs. This could be fatal to the foetus or could

cause severe anaemia and jaundice to the baby. This condition is called erythroblastosis

foetalis. This can be avoided by administering anti-Rh antibodies to the mother immediately

after the delivery of the first child

4. Solution: d)

Transpiration is affected by several external factors: temperature, light, humidity, wind

speed. Plant factors that affect transpiration include number and distribution of stomata, per

cent of open stomata, water status of the plant, canopy structure etc.

The transpiration driven ascent of xylem sap depends mainly on the following physical

properties of water:

Cohesion mutual attraction between water molecules.

Adhesion attraction of water molecules to polar surfaces (such as the surface of

tracheary elements).

Surface Tension water molecules are attracted to each other in the liquid phase more

than to water in the gas phase.

These properties give water high tensile strength, i.e. , an ability to resist a pulling force,

and high capillarity, i.e., the ability to rise in thin tubes. In plants capillarity is aided by the

small diameter of the tracheary elements the tracheids and vessel elements.

5. Solution: a)

The insolation received at the surface varies from about 320 Watt/m2 in the tropics to about

70 Watt/m2 in the poles. Maximum insolation is received over the subtropical deserts,

where the cloudiness is the least. Equator receives comparatively less insolation than the

tropics. Generally, at the same latitude the insolation is more over the continent than over

the oceans. In winter, the middle and higher latitudes receive less radiation than in summer.

6. Solution: a)

Explanation for Q 2 and 3 are given together. The phenomena of formation of red haze is

complex and chemical, hence only the information given is important.



7. Solution: c)

Atmospheric Aerosols:

What Are They, and Why Are They So Important?

Aerosols are minute particles suspended in the atmosphere. When these particles are

sufficiently large, we notice their presence as they scatter and absorb sunlight. Their

scattering of sunlight can reduce visibility (haze) and redden sunrises and sunsets.

Aerosols interact both directly and indirectly with the Earth's radiation budget and climate.

As a direct effect, the aerosols scatter sunlight directly back into space. As an indirect effect,

aerosols in the lower atmosphere can modify the size of cloud particles, changing how the

clouds reflect and absorb sunlight, thereby affecting the Earth's energy budget.

Aerosols also can act as sites for chemical reactions to take place (heterogeneous chemistry).

The most significant of these reactions are those that lead to the destruction of stratospheric

ozone. During winter in the polar regions, aerosols grow to form polar stratospheric clouds.

The large surface areas of these cloud particles provide sites for chemical reactions to take

place. These reactions lead to the formation of large amounts of reactive chlorine and,

ultimately, to the destruction of ozone in the stratosphere. Evidence now exists that shows

similar changes in stratospheric ozone concentrations occur after major volcanic eruptions,

like Mt. Pinatubo in 1991, where tons of volcanic aerosols are blown into the atmosphere

(Fig. 1).

Fig. 1 The dispersal of volcanic aerosols has a drastic effect on the Earth's atmosphere.

Following an eruption, large amounts of sulphur dioxide (SO2), hydrochloric acid (HCL)

and ash are spewed into the Earth's stratosphere. Hydrochloric acid, in most cases,

condenses with water vapor and is rained out of the volcanic cloud formation. Sulphur

dioxide from the cloud is transformed into sulphuric acid (H2SO4). The sulphuric acid

quickly condenses, producing aerosol particles which linger in the atmosphere for long

periods of time. The interaction of chemicals on the surface of aerosols, known as

heterogeneous chemistry, and the tendency of aerosols to increase levels of chlorine which



can react with nitrogen in the stratosphere, is a prime contributor to stratospheric ozone

destruction.

Rivers

Air POLLUTION can lead to increase in the water flowing through rivers. Pollutants known

as aerosols reduce the amount of sunlight reaching the Earth's atmosphere. This reduces

evaporation, thus increasing river flow. During the 1980s, river flow in the central European

river basin went up by 25 per cent when aerosol levels in the region were at their peak. The

study might help in dealing with water shortage, which is likely to be one of the biggest

impacts of climate change.

For More information:

http://earthobservatory.nasa.gov/Features/Aerosols/

8. Solution: d)

For a comprehensive understanding refer to:

http://www.preservearticles.com/2012021623388/what-are-the-harmful-effects-of-

hydrocarbons.html

9. Solution: d)

This question is important as these gases can combine and become sources of tropospheric

pollution. Dinitrogen and dioxygen are the main constituents of air.

These gases do not react with each other at a normal temperature. At high altitudes when

lightning strikes, they combine to form oxides of nitrogen. NO2 is oxidised to nitrate ion, 3

NO which is washed into soil, where it serves as a fertilizer. In an automobile engine, (at

high temperature) when fossil fuel is burnt, dinitrogen and dioxygen combine to yield

significant quantities of nitric oxide (NO) and nitrogen dioxide ( NO2 ).

10. Solution: a)

Humid Sub-tropical

Eastern parts of continents in sub-tropical latitudes (under the infleuence of

easterlies)

Air masses unstable and cause rainfall throughout the year of 75-150 cm annually

Temp max 27* C in summer, winter 5-12*C



Daily range of temperature is small

Found in

o NE Argentina

o South and East China

o Southern Japan

o Eastern Coasts Of Australia

o Eastern part of N-America

o Coastal South Africa

Marine West Coast climate

Located polewards from Mediterrenean climate

Under the influence of westerlies so rainfall varies greatly 50-250 cm annually

Moderate summer in summer (15-20* C) and in winter it is warmer than its latitude

because of sea effect (4-10*C)

Found in

o West coast of N-America

o SE Australia

o Southern Chile

o NW Europe

o North of California

o New Zealand

11. Solution: d)

Auxins (from Greek auxein : to grow) was first isolated from human urine. The term

auxin is applied to the indole-3-acetic acid (IAA), and to other natural and synthetic

compounds having certain growth regulating properties. They are generally produced by

the growing apices of the stems and roots, from where they migrate to the regions of their

action. Auxins like IAA and indole butyric acid (IBA) have been isolated from plants. NAA

(naphthalene acetic acid) and 2, 4-D (2, 4-dichlorophenoxyacetic) are synthetic auxins. All

these auxins have been used extensively in agricultural and horticultural practices. They

help to initiate rooting in stem cuttings, an application widely used for plant propagation.



Auxins promote flowering e.g. in pineapples. They help to prevent fruit and leaf drop at

early stages but promote the abscission of older mature leaves and fruits.

12. Solution: c)

Americans consume too much sodium, according to current guidelines, and much of the

excess may be hidden in our sandwiches, researchers say.

Based on national survey data depicting American eating habits over the course of a single

day, the study found that half of all adults had a sandwich. And those who did took in more

calories and sodium overall than those who didnt.

The study team calculates that sandwiches, on average, contribute about a fifth of the entire

days sodium intake for people who eat them.

High sodium intake has been linked to worsening high blood pressure, a condition that can,

in turn, increase the risk of heart disease, congestive heart failure and kidney disease,

according to the USDAs 2010 Dietary Guidelines for Americans.

The USDA recommends that everyone, including children, should limit their sodium intake

to no more than 2,300 milligrams per day, or about one teaspoon of salt.

13. Solution: a)

The optic nerves leave the eye and the retinal blood vessels enter it at a point medial to and

slightly above the posterior pole of the eye ball. Photoreceptor cells are not present in that

region and hence it is called the blind spot. At the posterior pole of the eye lateral to the

blind spot, there is a yellowish pigmented spot called macula lutea with a central pit called

the fovea. The fovea is a thinned-out portion of the retina where only the cones are densely

packed. It is the point where the visual acuity (resolution) is the greatest

14. Solution: d)

Acid rain refers to the ways in which acid from the atmosphere is deposited on the earths

surface. Oxides of nitrogen and sulphur which are acidic in nature can be blown by wind

along with solid particles in the atmosphere and finally settle down either on the ground as

dry deposition or in water, fog and snow as wet deposition.

Acid rain is a byproduct of a variety of human activities that emit the oxides of sulphur and

nitrogen in the atmosphere.

Burning of fossil fuels (which contain sulphur and nitrogenous matter) such as coal and oil

in power stations and furnace or petrol and diesel in motor engines produce sulphur dioxide

and nitrogen oxides. SO2 and NO2 after oxidation and reaction with water are major



contributors to acid rain, because polluted air usually contains particulate matters that

catalyse the oxidation.

15. Solution: a)

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. The former group of plants are

called long day plants while the latter ones are termed short day plants. The critical

duration is different for different plants. There are many plants, however, where there is no

such correlation between exposure to light duration and induction of flowering response;

such plants are called day-neutral plants. It is now also known that not only the duration of

light period but that the duration of dark period is also of equal importance. Hence, it can be

said that flowering in certain plants depends not only on a combination of light and dark

exposures but also their relative durations. This response of plants to periods of day/night is

termed photoperiodism.

16. Solution: c)

Agent Orange was a powerful mixture of chemical defoliants used by U.S. military forces

during the Vietnam War to eliminate forest cover for North Vietnamese and Viet Cong

troops, as well as crops that might be used to feed them. The U.S. program of defoliation,

codenamed Operation Ranch Hand, sprayed more than 19 million gallons of herbicides over

4.5 million acres of land in Vietnam from 1961 to 1972. Agent Orange, which contained the

chemical dioxin, was the most commonly used of the herbicide mixtures, and the most

effective. It was later revealed to cause serious health issuesincluding tumors, birth defects,

rashes, psychological symptoms and canceramong returning U.S. servicemen and their

families as well as among the Vietnamese population.

17. Solution: a)

Cars driven by polluting fuels should run on less polluting fossil fuels. If not, then catalytic

converters must be used in cars to reduce the effect of exhaust fumes on the atmosphere. The

main component of the converter is a ceramic honeycomb coated with precious metals

Pd, Pt and Rh. The exhaust gases containing unburnt fuel, CO and NOx, when pass through

the converter at 573 K, are converted into CO2 and N2.

18. Solution: b)

Explanation for Q10 and 11 are given together.

19. Solution: c)



The word smog is derived from smoke and fog.

This is the most common example of air pollution that occurs in many cities throughout the

world. There are two types of smog:

(a) Classical smog occurs in cool humid climate. It is a mixture of smoke, fog and sulphur

dioxide. Chemically it is a reducing mixture and so it is also called as reducing smog.

(b) Photochemical smog occurs in warm, dry and sunny climate. The main components of

the photochemical smog result from the action of sunlight on unsaturated hydrocarbons and

nitrogen oxides produced by automobiles and factories.

Photochemical smog has high concentration of oxidising agents and is, therefore, called as

oxidising smog.

20. Solution: a)

La Nina is a coupled ocean-atmosphere phenomenon that is the counterpart of El Nio as

part of the broader El NioSouthern Oscillation climate pattern. The name La Nia

originates from Spanish, meaning "the girl", analogous to El Nio meaning "the boy". It has

also in the past been called anti-El Nio, and El Viejo (meaning "the old man").[1] During a

period of La Nia, the sea surface temperature across the equatorial Eastern CentralPacific

Ocean will be lower than normal by 35 C. In the United States, an appearance of La Nia

happens for at least five months of La Nia conditions. It has extensive effects on the

weather in North America, even affecting the Atlantic Hurricane Season. La Nia often,

though not always, follows an El Nio.

21. Solution: a)

In India, as in Vietnam and many other colonies, the growth of modern nationalism is

intimately connected to the anti-colonial movement. People began discovering their unity in

the process of their struggle with colonialism. The sense of being oppressed under

colonialism provided a shared bond that tied many different groups together. But each class

and group felt the effects of colonialism differently, their experiences were varied, and their

notions of freedom were not always the same.

Though anti-colonial struggle led to unity among masses, it was not absolute. There was

disunity among different communities and between people with different political

ideologies.

22. Solution: d)

Effects of photochemical smog

The common components of photochemical smog are ozone, nitric oxide, acrolein,

formaldehyde and peroxyacetyl nitrate (PAN).



Photochemical smog causes serious health problems. Both ozone and PAN act as powerful

eye irritants. Ozone and nitric oxide irritate the nose and throat and their high concentration

causes headache, chest pain, dryness of the throat, cough and difficulty in breathing.

Photochemical smog leads to cracking of rubber and extensive damage to plant life. It also

causes corrosion of metals, stones, building materials, rubber and painted surfaces.

23. Solution: a)

Coriolis force: The deflection is more when the wind velocity is high. The Coriolis force is

directly proportional to the angle of latitude. It is maximum at the poles and is absent at the

equator. The Coriolis force acts perpendicular to the pressure gradient force. The pressure

gradient force is perpendicular to an isobar. The higher the pressure gradient force, the more

is the velocity of the wind and the larger is the deflection in the direction of wind.

24. Solution: d)

Effects of Depletion of the Ozone Layer

With the depletion of ozone layer, more UV radiation filters into troposphere. UV radiations

lead to ageing of skin, cataract, sunburn, skin cancer, killing of many phytoplanktons,

damage to fish productivity etc. It has also been reported that plant proteins get easily

affected by UV radiations which leads to the harmful mutation of cells. It also increases

evaporation of surface water through the stomata of the leaves and decreases the moisture

content of the soil. Increase in UV radiations damage paints and fibres, causing them to fade

faster.

25. Solution: d)

Out of the nine planets, mercury, venus, earth and mars are called as the inner planets as they

lie between the sun and the belt of asteroids the other five planets are called the outer planets.

Alternatively, the first four are called Terrestrial, meaning earth-like as they are made up of



rock and metals, and have relatively high densities. The rest five are called Jovian or Gas

Giant planets. Jovian means jupiter-like.

The difference between terrestrial and jovian planets can be attributed to the following

conditions:

(i) The terrestrial planets were formed in the close vicinity of the parent star where it was too

warm for gases to condense to solid particles. Jovian planets were formed at quite a distant

location.

(ii) The solar wind was most intense nearer the sun; so, it blew off lots of gas and dust from

the terrestrial planets. The solar winds were not all that intense to cause similar removal of

gases from the Jovian planets.

(iii) The terrestrial planets are smaller and their lower gravity could not hold the escaping

gases.

26. Solution: d)

During the cooling of the earth, gases and water vapour were released from the interior

solid earth. This started the evolution of the present atmosphere. The early atmosphere

largely contained water vapour, nitrogen, carbon dioxide, methane, ammonia and very little

of free oxygen. The process through which the gases were outpoured from the interior is

called degassing.

27. Solution: a)

There are three stages in the evolution of the present atmosphere. The first stage is marked

by the loss of primordial atmosphere. In the second stage, the hot interior of the earth

contributed to the evolution of the atmosphere. Finally, the composition of the atmosphere

was modified by the living world through the process of photosynthesis.

The early atmosphere, with hydrogen and helium, is supposed to have been stripped off as a

result of the solar winds. This happened not only in case of the earth, but also in all the

terrestrial planets, which were supposed to have lost their primordial atmosphere through

the impact of solar winds.

28. Solution: d)

Refer to page 22 of 11th physical NCERT Chapter 2. A detailed explanation is provided

there.

29. Solution: d)

Sources of earthquakes

Tectonic earthquakes - sliding of plates along a fault plane

Volcanic earthquakes



Collapse of roofs of underground mines

Explosions by chemicals

Reservoir induced earthquakes in areas where large reservoirs are located

30. Solution: a) Refer to a comprehensive explanation here with diagrams

http://loki.stockton.edu/~hozikm/geol/Courses/The%20Earth/Content%20Web%20Page

s/Bugielski/webpage.htm

31. Solution: d)

Earthquake Prone regions in the world

The Ring of Fire is an area where a large number of earthquakes and volcanic eruptions

occur in the basin of the Pacific Ocean.

In a 40,000 km (25,000 mi) horseshoe shape, it is associated with a nearly continuous series

of oceanic trenches, volcanic arcs, and volcanic belts and/or plate movements.

It has 452 volcanoes and is home to over 75% of the world's active and dormant

volcanoes. It is sometimes called the circum-Pacific belt or the circum-Pacific seismic belt.

About 90% of the world's earthquakes and 81% of the world's largest earthquakes occur

along the Ring of Fire.

The next most seismically active region (56% of earthquakes and 17% of the world's largest

earthquakes) is the Alpide belt, which extends from Java to Sumatra through

the Himalayas, the Mediterranean, and out into the Atlantic.

The Mid-Atlantic Ridge is the third most prominent earthquake belt.

The Ring of Fire is a direct result of plate tectonics and the movement and collisions

of lithospheric plates

32. Solution: d)

Concept of Sea Floor Spreading

The mapping of the ocean floor and palaeomagnetic studies of rocks from oceanic regions

revealed the following facts:

(i) It was realised that all along the midoceanic ridges, volcanic eruptions are common and

they bring huge amounts of lava to the surface in this area.

(ii) The rocks equidistant on either sides of the crest of mid-oceanic ridges show remarkable

similarities in terms of period of formation, chemical compositions and magnetic properties.

Rocks closer to the mid-oceanic ridges are normal polarity and are the youngest. The age of

the rocks increases as one moves away from the crest.



(iii) The ocean crust rocks are much younger than the continental rocks. The age of rocks in

the oceanic crust is nowhere more than 200 million years old. Some of the continental rock

formations are as old as 3,200 million old.

(iv) The sediments on the ocean floor are unexpectedly very thin.

(v) The deep trenches have deep-seated earthquake occurrences while in the mid-oceanic

ridge areas, the quake foci have shallow depths. It means lava is in close vicinity.

These facts and a detailed analysis of magnetic properties of the rocks on either sides of the

mid-oceanic ridge led Hess (1961) to propose his hypothesis, known as the sea floor

spreading.

Hess argued that constant eruptions at the crest of oceanic ridges cause the rupture of the

oceanic crust and the new lava wedges into it, pushing the oceanic crust on either side. The

ocean floor, thus spreads.

The younger age of the oceanic crust as well as the fact that the spreading of one ocean does

not cause the shrinking of the other. Instead the ocean floor sinks down and is consumed.

33. Solution: a)

Major elements of earths crust

34. Solution: c)

Igneous rocks are classified based on texture. Texture depends upon size and arrangement

of grains or other physical conditions of the materials. If molten material is cooled slowly at

great depths, mineral grains may be very large. Sudden cooling (at the surface) results in

small and smooth grains. Intermediate conditions of cooling would result in intermediate

sizes of grains making up igneous rocks. Granite, gabbro, pegmatite, basalt, volcanic breccia

and tuff are some of the examples of igneous rocks.

Depending upon the mode of formation, sedimentary rocks are classified into three major

groups: (i) mechanically formed sandstone, conglomerate, limestone, shale, loess etc. Are



examples; (ii) organically formed geyserite, chalk, limestone, coal etc. are some examples;

(iii) chemically formed chert, limestone, halite, potash etc. are some examples.

35. Solution: d)

Refer to http://agritech.tnau.ac.in/agriculture/agri_pgr.html

Or refer to the section 15.3 in Chapter 15 Bio Class 11th NCERT

36. Solution: d)

The energy emanating from within the earth is the main force behind endogenic geomorphic

processes. This energy is mostly generated by radioactivity, rotational and tidal friction and

primordial heat from the origin of the earth. This energy due to geothermal gradients and

heat flow from within induces diastrophism and volcanism in the lithosphere. Due to

variations in geothermal gradients and heat flow from within, crustal thickness and

strength, the action of endogenic forces are not uniform and hence the tectonically controlled

original crustal surface is uneven.

37. Solution: d)

Physical or mechanical weathering processes depend on some applied forces. The applied

forces could be:

(i) Gravitational forces such as overburden pressure, load and shearing stress;

(ii) Expansion forces due to temperature changes, crystal growth or animal activity;

(iii) Water pressures controlled by wetting and drying cycles.

Many of these forces are applied both at the surface and within different earth materials

leading to rock fracture. Most of the physical weathering processes are caused by thermal

expansion and pressure release. These processes are small and slow but can cause great

damage to the rocks because of continued fatigue the rocks suffer due to repetition of

contraction and expansion.

38. Solution: c)

In our country, debris avalanche and landslides occur very frequently in the Himalayas.

There are many reasons for this. One, the Himalayas are tectonically active. They are mostly

made up of sedimentary rocks and unconsolidated and semi-consolidated deposits. The

slopes are very steep. Compared to the Himalayas, the Nilgiris bordering Tamilnadu,

Karnataka, Kerala and the Western Ghats along the west coast are relatively tectonically

stable and are mostly made up of very hard rocks; but, still, debris avalanches and

landslides occur though not as frequently as in the Himalayas, in these hills. Why? Many

slopes are steeper with almost vertical cliffs and escarpments in the Western Ghats and

Nilgiris. Mechanical weathering due to temperature changes and ranges is pronounced.

They receive heavy amounts of rainfall over short periods. So, there is almost direct rock fall

quite frequently in these places along with landslides and debris avalanches.



39. Solution: a)

Temperature acts in two ways increasing or reducing chemical and biological activity.

Chemical activity is increased in higher temperatures, reduced in cooler temperatures (with

an exception of carbonation) and stops in freezing conditions. That is why, tropical soils

with higher temperatures show deeper profiles and in the frozen tundra regions soils

contain largely mechanically broken materials.

EXTRA Question (1) Solution: d)

Macronutrients are generally present in plant tissues in large amounts (in excess of 10

mmole Kg 1 of dry matter). The macronutrients include carbon, hydrogen, oxygen,

nitrogen, phosphorous, sulphur, potassium, calcium and magnesium. Of these, carbon,

hydrogen and oxygen are mainly obtained from CO2 and H2O, while the others are

absorbed from the soil as mineral nutrition.

40. Solution: d)

Difference Alluvial fans and Deltas Alluvial fans

Water flowing from a higher level breaks down into foot slope plains of low gradient

Normally very coarse load is carried by streams in the upper reaches

It becomes too heavy to carry and is deposited in low to high cone shaped deposit called alluvial fan

No stratification of river load a all the material (fine and coarse) is dumped together

Streams making alluvial fans eventually shifts course forming many channels called distributaries Deltas

They are like alluvial fans but are formed at different location i.e. near the sea

Water is flowing at a very low slope and is at the lowest reaches

Very fine sediment load is being carried; if not carried into the sea, then deposited as a low cone called delta.

Delta deposits are well stratified with coarser material settling first and the finer

As Delta grows distributaries also grow in size

41. Solution: c)

Greenhouse gases are those that can absorb and emit infrared radiation, but not radiation in

or near the visible spectrum. In order, the most abundant greenhouse gases in Earth's

atmosphere are:

Water vapor (H2O)

Carbon dioxide (CO2)

Methane (CH4)

Nitrous oxide (N2O)



Ozone (O3)

CFCs

Atmospheric concentrations of greenhouse gases are determined by the balance between

sources (emissions of the gas from human activities and natural systems) and sinks (the

removal of the gas from the atmosphere by conversion to a different chemical compound).

42. Solution: a)

Mahatma Gandhi on Satyagraha

It is said of passive resistance that it is the weapon of the weak, but the power which is

the subject of this article can be used only by the strong. This power is not passive resistance;

indeed it calls for intense activity. The movement in South Africa was not passive but active

Satyagraha is not physical force. A satyagrahi does not inflict pain on the adversary; he

does not seek his destruction In the use of satyagraha, there is no ill-will whatever.

Satyagraha is pure soul-force. Truth is the very substance of the soul. That is why this force

is called satyagraha. The soul is informed with knowledge. In it burns the flame of love.

non- violence is the supreme dharma

It is certain that India cannot rival Britain or Europe in force of arms. The British worship

the war-god and they can all of them become, as they are becoming, bearers of arms. The

hundreds of millions in India can never carry arms. They have made the religion of non-

violence their own ...

43. Solution: a)

Refer to http://www.cotf.edu/ete/modules/carbon/efculprits3.html

44. Solution: a)



The figure above shows that there is a surplus of net radiation balance between 40 degrees

north and south and the regions near the poles have a deficit. The surplus heat energy from

the tropics is redistributed pole wards and as a result the tropics do not get progressively

heated up due to the accumulation of excess heat or the high latitudes get permanently

frozen due to excess deficit.

45. Solution: d)

The temperature distribution is generally shown on the map with the help of isotherms. The

Isotherms are lines joining places having equal temperature.

In general the effect of the latitude on temperature is well pronounced on the map, as the

isotherms are generally parallel to the latitude. The deviation from this general trend is more

pronounced in January than in July, especially in the northern hemisphere. In the northern

hemisphere the land surface area is much larger than in the southern hemisphere.

Hence, the effects of land mass and the ocean currents are well pronounced. In January the

isotherms deviate to the north over the ocean and to the south over the continent. This can

be seen on the North Atlantic Ocean. The presence of warm ocean currents, Gulf Stream and

North Atlantic drift, make the Northern Atlantic Ocean warmer and the isotherms bend

towards the north. Over the land the temperature decreases sharply and the isotherms bend

towards south in Europe.

This is shown in the diagram below.



46. Solution: a)

In 1980s atmospheric scientists working in Antarctica reported about depletion of ozone

layer commonly known as ozone hole over the South Pole. It was found that a unique set of

conditions was responsible for the ozone hole.

In summer season, nitrogen dioxide and methane react with chlorine monoxide and chlorine

atoms forming chlorine sinks, preventing much ozone depletion, whereas in winter, special

type of clouds called polar stratospheric clouds are formed over Antarctica. These polar

stratospheric clouds provide surface on which chlorine nitrate formed

47. Solution: c)

The higher the pressure gradient force, the more is the velocity of the wind and the larger is

the deflection in the direction of wind. As a result of these two forces operating

perpendicular to each other, in the low-pressure areas the wind blows around it. At the

equator, the Coriolis force is zero and the wind blows perpendicular to the isobars. The low

pressure gets filled instead of getting intensified. That is the reason why tropical cyclones

are not formed near the equator.

48. Solution: a)

The hypothalamus a part of forebrain- contains a number of centres which control body

temperature, urge for eating and drinking. It also contains several groups of neurosecretory

cells, which secrete hormones called hypothalamic hormones. The inner parts of cerebral

hemispheres and a group of associated deep structures like amygdala, hippocampus, etc.,

form a complex structure called the limbic lobe or limbic system. Along with the

hypothalamus, it is involved in the regulation of sexual behaviour, expression of emotional

reactions (e.g., excitement, pleasure, rage and fear), and motivation.

49. Solution: a)

Warming and cooling of the Pacific Ocean is most important in terms of general atmospheric

circulation. The warm water of the central Pacific Ocean slowly drifts towards South

American coast and replaces the cool Peruvian current. Such appearance of warm water off

the coast of Peru is known as the El Nino.

The El Nino event is closely associated with the pressure changes in the Central Pacific and

Australia. This change in pressure condition over Pacific is known as the southern

oscillation.

50. Solution: d)

The irritant red haze in the traffic and congested places is due to oxides of nitrogen.

Higher concentrations of NO2 damage the leaves of plants and retard the rate of

photosynthesis. Nitrogen dioxide is a lung irritant that can lead to an acute respiratory



disease in children. It is toxic to living tissues also. Nitrogen dioxide is also harmful to

various textile fibres and metals.

51. Solution: a)

The First World War had ended with the defeat of Ottoman Turkey. And there were

rumours that a harsh peace treaty was going to be imposed on the Ottoman emperor the

spiritual head of the Islamic world (the Khalifa). To defend the Khalifas temporal powers, a

Khilafat Committee was formed in Bombay in March 1919. A young generation of Muslim

leaders like the brothers Muhammad Ali and Shaukat Ali, began discussing with Mahatma

Gandhi about the possibility of a united mass action on the issue. Gandhiji saw this as an

opportunity to bring Muslims under the umbrella of a unified national movement. At the

Calcutta session of the Congress in September 1920, he convinced other leaders of the need

to start a non-cooperation movement in support of Khilafat as well as for swaraj.

52. Solution: a)

More than 200 Cm per annum

Equatorial belt (also evenly distributed)

Windward sides of mountain

Western coasts of cool temperate zones (also evenly distributed)

Coastal areas of monsoon land

100-200 Cm per annum

Interior continental areas

Coastal area of the continents

50-100 cm per annum

Central parts of tropical land

Eastern and interior parts of temperate zones like Ukraine

Rainshadow zone and interior of continents at high latitudes

53. Solution: b)

Species which are not the natural inhabitants of the local habitat but are introduced into the

system, are called exotic species. There are many examples when a natural biotic community

of the ecosystem suffered extensive damage because of the introduction of exotic species.



54. Solution: a)

In June 1920, Jawaharlal Nehru began going around the villages in Awadh, talking to the

villagers, and trying to understand their grievances. By October, the Oudh Kisan Sabha was

set up headed by Jawaharlal Nehru, Baba Ramchandra and a few others. Within a month,

over 300 branches had been set up in the villages around the region. So when the Non-

Cooperation Movement began the following year, the effort of the Congress was to integrate

the Awadh peasant struggle into the wide struggle. The peasant movement, however,

developed in forms that the Congress leadership was unhappy with. As the movement

spread in 1921, the houses of talukdars and merchants were attacked, bazaars were looted,

and grain hoards were taken over. In many places local leaders told peasants that Gandhiji

had declared that no taxes were to be paid and land was to be redistributed among the poor.

The name of the Mahatma was being invoked to sanction all action and aspirations.

55. Solution: d)

56. Solution: a)

In his famous book Hind Swaraj (1909) Mahatma Gandhi declared that British rule was

established in India with the cooperation of Indians, and had survived only because of this



cooperation. If Indians refused to cooperate, British rule in India would collapse within a

year, and swaraj would come.

How could non-cooperation become a movement? Gandhiji proposed that the movement

should unfold in stages. It should begin with the surrender of titles that the government

awarded, and a boycott of civil services, army, police, courts and legislative councils,

schools, and foreign goods. Then, in case the government used repression, a full civil

disobedience campaign would be launched.

Through the summer of 1920 Mahatma Gandhi and Shaukat Ali toured extensively,

mobilising popular support for the movement. Many within the Congress were, however,

concerned about the proposals. They were reluctant to boycott the council elections

scheduled for November 1920, and they feared that the movement might lead to popular

violence. In the months between September and December there was an intense tussle

within the Congress. For a while there seemed no meeting point between the supporters and

the opponents of the movement. Finally, at the Congress session at Nagpur in December

1920, a compromise was worked out and the Non-Cooperation programme was adopted.

57. Solution: c)

Against this background the new Tory government in Britain constituted a Statutory

Commission under Sir John Simon. Set up in response to the nationalist movement, the

commission was to look into the functioning of the constitutional system in India and

suggest changes. The problem was that the commission did not have a single Indian

member. They were all British.

When the Simon Commission arrived in India in 1928, it was greeted with the slogan Go

back Simon. All parties, including the Congress and the Muslim League, participated in the

demonstrations. In an effort to win them over, the viceroy, Lord Irwin, announced in

October 1929, a vague offer of dominion status for India in an unspecified future, and a

Round Table Conference to discuss a future constitution. This did not satisfy the Congress

leaders.

58. Solution: a)



59. Solution: d)

The effects of non-cooperation on the economic front were more dramatic. Foreign goods

were boycotted, liquor shops picketed, and foreign cloth burnt in huge bonfires. The import

of foreign cloth halved between 1921 and 1922, its value dropping from Rs 102 crore to Rs 57

crore. In many places merchants and traders refused to trade in foreign goods or finance

foreign trade. As the boycott movement spread, and people began discarding imported

clothes and wearing only Indian ones, production of Indian textile mills and handlooms

went up.

But this movement in the cities gradually slowed down for a variety of reasons. Khadi cloth

was often more expensive than mass- produced mill cloth and poor people could not afford

to buy it. How then could they boycott mill cloth for too long? Similarly the boycott of

British institutions posed a problem. For the movement to be successful, alternative Indian

institutions had to be set up so that they could be used in place of the British ones. These

were slow to come up. So students and teachers began trickling back to government schools

and lawyers joined back work in government courts.

60. Solution: c)

Continental Shelf

The continental shelf is the extended margin of each continent occupied by relatively

shallow seas and gulfs. It is the shallowest part of the ocean showing an average gradient of

1 or even less. The shelf typically ends at a very steep slope, called the shelf break.

It can be narrow or even wide upto 1,500 Km like Siberian shelf.

The continental shelves are covered with variable thicknesses of sediments brought down by

rivers, glaciers, wind, from the land and distributed by waves and currents. Massive

sedimentary deposits received over a long time by the continental shelves, become the

source of fossil fuels.

Oceanic Deeps or Trenches

These areas are the deepest parts of the oceans. The trenches are relatively steep sided,

narrow basins. They are some 3-5 km deeper than the surrounding ocean floor. They occur

at the bases of continental slopes and along island arcs and are associated with active

volcanoes and strong earthquakes. That is why they are very significant in the study of plate

movements.

61. Solution: c)

Salinity changes with depth, but the way it changes depends upon the location of the sea.

Salinity at the surface increases by the loss of water to ice or evaporation, or decreased by

the input of fresh waters, such as from the rivers. Salinity at depth is very much fixed,



because there is no way that water is lost, or the salt is added. There is a marked

difference in the salinity between the surface zones and the deep zones of the oceans. The

lower salinity water rests above the higher salinity dense water. Salinity, generally, increases

with depth and there is a distinct zone called the halocline, where salinity increases sharply.

Other factors being constant, increasing salinity of seawater causes its density to increase.

High salinity seawater, generally, sinks below the lower salinity water. This leads to

stratification by salinity.

62. Solution: b)

Mahatma Gandhi once again decided to call of the civil dispobedience movement and

entered into a pact with Irwin on 5 March 1931. By this Gandhi-Irwin Pact, Gandhiji

consented to participate in a Round Table Conference (the Congress had boycotted the first

Round Table Conference) in London and the government agreed to release the political

prisoners. In December 1931, Gandhiji went to London for the conference, but the

negotiations broke down and he returned disappointed. Back in India, he discovered that

the government had begun a new cycle of repression. Ghaffar Khan and Jawaharlal Nehru

were both in jail, the Congress had been declared illegal, and a series of measures had been

imposed to prevent meetings, demonstrations and boycotts. With great apprehension,

Mahatma Gandhi relaunched the Civil Disobedience Movement. For over a year, the

movement continued, but by 1934 it lost its momentum.

63. Solution: d)

The primary forces that influence the currents are: (i) heating by solar energy; (ii) wind; (iii)

gravity; (iv) coriolis force.

Heating by solar energy causes the water to expand. That is why, near the equator the ocean

water is about 8 cm higher in level than in the middle latitudes. This causes a very slight

gradient and water tends to flow down the slope. Wind blowing on the surface of the ocean

pushes the water to move. Friction between the wind and the water surface affects the

movement of the water body in its course. Gravity tends to pull the water down to pile and

create gradient variation. The Coriolis force intervenes and causes the water to move to the

right in the northern hemisphere and to the left in the southern hemisphere.

64. Solution: d)

Movement by diffusion is passive, and may be from one part of the cell to the other, or from

cell to cell, or over short distances, say, from the intercellular spaces of the leaf to the

outside. No energy expenditure takes place.

In diffusion, molecules move in a random fashion, the net result being substances moving

from regions of higher concentration to regions of lower concentration. Diffusion is a slow

process and is not dependent on a living system. Diffusion is obvious in gases and liquids,

but diffusion in solids rather than of solids is more likely. Diffusion is very important to plants

since it is the only means for gaseous movement within the plant body. Diffusion rates are



affected by the gradient of concentration, the permeability of the membrane separating

them, temperature and pressure.

Active transport uses energy to pump molecules against a concentration gradient. Active

transport is carried out by membrane-proteins. Hence different proteins in the membrane

play a major role in both active as well as passive transport. Pumps are proteins that use

energy to carry substances across the cell membrane. These pumps can transport substances

from a low concentration to a high concentration (uphill transport). Transport rate reaches

a maximum when all the protein transporters are being used or are saturated. Like enzymes

the carrier protein is very specific in what it carries across the membrane. These proteins are

sensitive to inhibitors that react with protein side chains.

65. Solution: a)

During the First World War, Indian merchants and industrialists had made huge profits and

become powerful. Keen on expanding their business, they now reacted against colonial

policies that restricted business activities. They wanted protection against imports of foreign

goods, and a rupee-sterling foreign exchange ratio that would discourage imports. To

organise business interests, they formed the Indian Industrial and Commercial Congress in

1920 and the Federation of the Indian

Chamber of Commerce and Industries (FICCI) in 1927. Led by prominent industrialists like

Purshottamdas Thakurdas and G. D. Birla, the industrialists attacked colonial control over

the Indian economy, and supported the Civil Disobedience Movement when it was first

launched. They gave financial assistance and refused to buy or sell imported goods. Most

businessmen came to see swaraj as a time when colonial restrictions on business would no

longer exist and trade and industry would flourish without constraints. But after the failure

of the Round Table Conference, business groups were no longer uniformly enthusiastic.

They were apprehensive of the spread of militant activities, and worried about prolonged

disruption of business, as well as of the growing influence of socialism amongst the younger

members of the Congress. The industrial working classes did not participate in the Civil

Disobedience Movement in large numbers, except in the Nagpur region. As the

industrialists came closer to the Congress, workers stayed aloof.

66. Solution: a)

Osmosis is the term used to refer specifically to the diffusion of water across a differentially-

or semi-permeable membrane. Osmosis occurs spontaneously in response to a driving force.

The net direction and rate of osmosis depends on both the pressure gradient and

concentration gradient. Water will move from its region of higher chemical potential (or

concentration) to its region of lower chemical potential until equilibrium is reached. At

equilibrium the two chambers should have the same water potential.

67. Solution: d)

Transpiration is the evaporative loss of water by plants. It occurs mainly through the

stomata in the leaves. Besides the loss of water vapour in transpiration, exchange of oxygen



and carbon dioxide in the leaf also occurs through pores called stomata (sing. : stoma).

Normally stomata are open in the day time and close during the night. The immediate cause

of the opening or closing of the stomata is a change in the turgidity of the guard cells. The

inner wall of each guard cell, towards the pore or stomatal aperture, is thick and elastic.

When turgidity increases within the two guard cells flanking each stomatal aperture or pore,

the thin outer walls bulge out and force the inner walls into a crescent shape. The opening of

the stoma is also aided due to the orientation of the microfibrils in the cell walls of the guard

cells.

68. Solution: a)

http://www.nature.com/nature/journal/v295/n5851/abs/295683a0.html

69. Solution: c)

It was in the twentieth century, with the growth of nationalism, that the identity of India

came to be visually associated with the image of Bharat Mata. The image was first created by

Bankim Chandra Chattopadhyay. In the 1870s he wrote Vande Mataram as a hymn to the

motherland. Later it was included in his novel Anandamath and widely sung during the

Swadeshi movement in Bengal. Moved by the Swadeshi movement, Abanindranath Tagore

painted his famous image of Bharat Mata. In this painting Bharat Mata is portrayed as an

ascetic figure; she is calm, composed, divine and spiritual. In subsequent years, the image of

Bharat Mata acquired many different forms, as it circulated in popular prints, and was

painted by different artists. Devotion to this mother figure came to be seen as evidence of

ones nationalism.

70. Solution: a)

High Rocky coast

The west coast of our country is a high rocky retreating coast. Erosional forms dominate in

the west coast. Whereas, the east coast of India is a low sedimentary coast. Depositional

forms dominate in the east coast.

Features:

Highly indented

Formation of wave-cut platforms in front of the sea cliff due to constant water

erosional action

Material eroded in such manner, deposits along the off-shore forming wave terraces.

Several depositions like this results in the formation of barrier bars and spits that

break block the sea water forming a lagoon.

Low Sedimentary coast

Features:



Lagoons, deltas etc. found

Lagoons eventually turn into swamps which turn into coastal plains

Storm and tsunami waves cause darastic changes in the supply of depositional

material

71. Solution: d)

Transpiration has more than one purpose; it

creates transpiration pull for absorption and transport of plants

supplies water for photosynthesis

transports minerals from the soil to all parts of the plant

cools leaf surfaces, sometimes 10 to 15 degrees, by evaporative cooling

maintains the shape and structure of the plants by keeping cells turgid

An actively photosynthesising plant has an insatiable need for water. Photosynthesis is

limited by available water which can be swiftly depleted by transpiration. The humidity of

rainforests is largely due to this vast cycling of water from root to leaf to atmosphere and

back to the soil.

72. Solution: c)

The example of indentured labour migration from India also illustrates the two-sided nature

of the nineteenth-century world. It was a world of faster economic growth as well as great

misery, higher incomes for some and poverty for others, technological advances in some

areas and new forms of coercion in others.

In the nineteenth century, hundreds of thousands of Indian and Chinese labourers went to

work on plantations, in mines, and in road and railway construction projects around the

world. In India, indentured labourers were hired under contracts which promised return

travel to India after they had worked five years on their employers plantation.

Most Indian indentured workers came from the present-day regions of eastern Uttar

Pradesh, Bihar, central India and the dry districts of Tamil Nadu. In the mid-nineteenth

century these regions experienced many changes cottage industries declined, land rents

rose, lands were cleared for mines and plantations. All this affected the lives of the poor:

they failed to pay their rents, became deeply indebted and were forced to migrate in search

of work.

73. Solution: a)



Thunderstorms are caused by intense convection on moist hot days. A thunderstorm is a

well-grown cumulonimbus cloud producing thunder and lightening. When the clouds

extend to heights where sub-zero temperature prevails, hails are formed and they come

down as hailstorm. If there is insufficient moisture, a thunderstorm can generate duststorms.

A thunderstorm is characterised by intense updraft of rising warm air, which causes the

clouds to grow bigger and rise to greater height. This causes precipitation.

74. Solution: a)

In 1860, Julius von Sachs, a prominent German botanist, demonstrated, for the first time, that

plants could be grown to maturity in a defined nutrient solution in complete absence of soil.

This technique of growing plants in a nutrient solution is known as hydroponics. Since then,

a number of improvised methods have been employed to try and determine the mineral

nutrients essential for plants. The essence of all these methods involves the culture of plants

in a soil-free, defined mineral solution. These methods require purified water and mineral

nutrient salts.

75. Solution: b)

In the early 1930s religious and social movement called Rastafarianism evolved in

Jamaica. Rastas sought to provide a voice for the poor Blacks in Jamaica by encouraging

resistance to oppressive societal structures. At the core of their belief is the re-interpretation

of the Hebrew Bible with a focus on Blacks as Gods chosen race, and the belief that the true

Messiah comes to us as Emperor Haile Selassie I (Ras Tafari) of Ethiopia. Through

extensive spoken discourse, the Rastafarians aim to clarify the Western misinterpretation of

the Bible, so as to spread the true word and fight against the unjust hierarchy of Western

culture (collectively called Babylon). In the meantime, Rastafarians await a time of

repatriation of Blacks and a return to Ethiopia, qua Africa, of its rightful ruling status.



76. Solution: c)

Micronutrients or trace elements, are needed in very small amounts (less than 10 mmole Kg

1 of dry matter). These include iron, manganese, copper, molybdenum, zinc, boron,

chlorine and nickel. In addition to the 17 essential elements named above, there are some

beneficial elements such as sodium, silicon, cobalt and selenium. They are required by

higher plants.

77. Solution: d)

Iron: Plants obtain iron in the form of ferric ions (Fe3+). It is required in larger amounts in

comparison to other micronutrients. It is an important constituent of proteins involved in

the transfer of electrons like ferredoxin and cytochromes. It is reversibly oxidised from Fe2+

to Fe3+ during electron transfer. It activates catalase enzyme, and is essential for the

formation of chlorophyll.

78. Solution: a)

Over the nineteenth century, British manufactures flooded the Indian market. Food grain

and raw material exports from India to Britain and the rest of the world increased. But the

value of British exports to India was much higher than the value of British imports from

India. Thus Britain had a trade surplus with India. Britain used this surplus to balance its

trade deficits with other countries that is, with countries from which Britain was importing

more than it was selling to. This is how a multilateral settlement system works it allows

one countrys deficit with another country to be settled by its surplus with a third country.

By helping Britain balance its deficits, India played a crucial role in the late-nineteenth-

century world economy.

79. Solution: d)



In nature, lightning and ultraviolet radiation provide enough energy to convert nitrogen to

nitrogen oxides (NO, NO2, N 2O). Industrial combustions, forest fires, automobile exhausts

and power-generating stations are also sources of atmospheric nitrogen oxides.

80. Solution: b)

The history of many business groups goes back to trade with China. From the late

eighteenth century, as you have read in your book last year, the British in India began

exporting opium to China and took tea from China to England. Many Indians became junior

players in this trade, providing finance, procuring supplies, and shipping consignments.

Having earned through trade, some of these businessmen had visions of developing

industrial enterprises in India.

In Bengal, Dwarkanath Tagore made his fortune in the China trade before he turned to

industrial investment, setting up six joint-stock companies in the 1830s and 1840s. Tagores

enterprises sank along with those of others in the wider business crises of the 1840s, but later

in the nineteenth century many of the China traders became successful industrialists.

81. Solution: a)

Several types of symbiotic biological nitrogen fixing associations are known. The most

prominent among them is the legume-bacteria relationship. Species of rod-shaped Rhizobium

has such relationship with the roots of several legumes such as alfalfa, sweet clover, sweet



pea, lentils, garden pea, broad bean, clover beans, etc. The most common association on

roots is as nodules. These nodules are small outgrowths on the roots. The microbe, Frankia,

also produces nitrogen-fixing nodules on the roots of nonleguminous plants (e.g., Alnus).

Both Rhizobium and Frankia are freeliving in soil, but as symbionts, can fix atmospheric

nitrogen.

82. Solution: d)

The average salinity of the Indian Ocean is 35 o/oo. The low salinity trend is observed in the

Bay of Bengal due to influx of river water by the river Ganga. On the contrary, the Arabian

Sea shows higher salinity due to high evaporation and low influx of fresh water.

83. Solution: c)

The Bengal Renaissance refers to a socio-cultural and religious reform movement during

the nineteenth and early twentieth century in undivided India's Bengal province, though the

impact of it spread in the whole of India. The Bengal Renaissance is said to have begun

with Raja Ram Mohan Roy (17751833) and continued until the death of Rabindranath

Tagore in 1941.The Renaissance was a revival of the positives of India's past and

appreciation of the impact of the Modern West, as it had emerged since the Fifteenth-

century European Renaissance.

84. Solution: d)

An understanding of the factors that affect photosynthesis is necessary. The rate of

photosynthesis is very important in determining the yield of plants including crop plants.

Photosynthesis is under the influence of several factors, both internal (plant) and external.

The plant factors include the number, size, age and orientation of leaves, mesophyll cells

and chloroplasts, internal CO2 concentration and the amount of chlorophyll. The plant or

internal factors are dependent on the genetic predisposition and the growth of the plant.

The external factors would include the availability of sunlight, temperature, CO2

concentration and water. As a plant photosynthesises, all these factors will simultaneously

affect its rate. Hence, though several factors interact and simultaneously affect

photosynthesis or CO2 fixation, usually one factor is the major cause or is the one that limits

the rate. Hence, at any point the rate will be determined by the factor available at sub-

optimal levels.

85. Solution: a)

There are plants for which flowering is either quantitatively or qualitatively dependent on

exposure to low temperature. This phenomenon is termed vernalisation. It prevents

precocious reproductive development late in the growing season, and enables the plant to

have sufficient time to reach maturity. Vernalisation refers specially to the promotion of



flowering by a period of low temperature. Some important food plants, wheat, barley, rye

have two kinds of varieties: winter and spring varieties. The spring variety are normally

planted in the spring and come to flower and produce grain before the end of the growing

season. Winter varieties, however, if planted in spring would normally fail to flower or

produce mature grain within a span of a flowering season. Hence, they are planted in

autumn.

86. Solution: a)

A polar vortex is a persistent, large-scale cyclone that circles either of the

planet's geographical poles. OnEarth, the base of the polar vortices are located in the middle

and upper troposphere and extend into thestratosphere. They surround the polar highs and

lie in the wake of the polar front. These cold-core low-pressure areas strengthen in the

winter and weaken in the summer due to their dependence upon the temperature

differential between the equator and the poles.[1] They usually span less than

1,000 kilometers (620 miles) in diameter within which the air circulates in a counter-

clockwise fashion in the Northern Hemisphere, and in a clockwise fashion in the Southern

Hemisphere. As with other cyclones, their rotation is caused by the Coriolis effect.

http://www.downtoearth.org.in/content/polar-vortex-may-freeze-parts-us-again-winter

87. Solution: a)

88. Solution: c)



89. Solution: c)

Gandhiji in 1919 decided to launch a nationwide satyagraha against the proposed Rowlatt

Act (1919). This Act had been hurriedly passed through the Imperial Legislative Council

despite the united opposition of the Indian members. It gave the government enormous

powers to repress political activities, and allowed detention of political prisoners without

trial for two years. Mahatma Gandhi wanted non-violent civil disobedience against such

unjust laws, which would start with a hartal on 6 April.

90. Solution: d)

The wind blows from high pressure to low pressure. The wind at the surface experiences

friction. In addition, rotation of the earth also affects the wind movement. The force exerted

by the rotation of the earth is known as the Coriolis force. Thus, the horizontal winds near

the earth surface respond to the combined effect of three forces the pressure gradient force,

the frictional force and the Coriolis force. In addition, the gravitational force acts downward.

91. Solution: b)

Over India, a subtropical westerly jet develops in the winter season which is replaced by

the tropical easterly jet in the summer season. The high temperature over the Tibetan Plateau,

as well as over Central Asia in general, during the summer is believed to be the critical

factor leading to the formation of the tropical easterly jet over India in summer. The

mechanism affecting monsoon is that the westerly jet causes high pressure over northern

parts of the subcontinent during the winter. This results in the north to south flow of the

winds in the form of the NE Monsoon. With the northwards shift of the vertical sun, this jet

shifts northwards too. The intense heat over the Tibetan Plateau, coupled with

associated terrain features of high altitude of the plateau, etc. generate the tropical easterly

jet over central India. This jet creates a low pressure zone over the northern Indian

plains influencing the wind flow towards these plains, assisting the establishment of the SW

Monsoon.



http://www.downtoearth.org.in/dte/userfiles/images/20140430-22pdfl.pdf

92. Solution: d)

The movability at body joints vary depending on different factors. Joints have been classified

into three major structural forms, namely, fibrous, cartilaginous and synovial.

Fibrous joints do not allow any movement. This type of joint is shown by the flat skull

bones which fuse end-to-end with the help of dense fibrous connective tissues in the form of

sutures, to form the cranium.

In cartilaginous joints, the bones involved are joined together with the help of cartilages.

The joint between the adjacent vertebrae in the vertebral column is of this pattern and it

permits limited movements.

Synovial joints are characterised by the presence of a fluid filled synovial cavity between

the articulating surfaces of the two bones. Such an arrangement allows considerable

movement. These joints help in locomotion and many other movements. Ball and socket

joint (between humerus and pectoral girdle), hinge joint (knee joint), pivot joint (between

atlas and axis), gliding joint (between the carpals) and saddle joint (between carpal and

metacarpal of thumb) are some examples.

93. Solution: d)

Excessive phytoplankton growth within water is also a cause of water pollution. The large

population of bacteria decomposes organic matter present in water. They consume oxygen

dissolved in water. The amount of oxygen that water can hold in the solution is limited.

94. Solution: a)

The Humboldt Current is a cold, low-salinity ocean current that flows north along the west

coast of South America from the southern tip of Chile to northern Peru. Also called the Peru

Current, it is an eastern boundary current flowing in the direction of the equator, and can

extend 1,000 kilometers offshore.



95. Solution: d)

Dry Climates - Group B

Very low rainfall inadequate for the growth of plants

Large areas of the earth extending 15-60* N-S of the equator

At low latitudes they occur in 15-30*N-S areas of subtropical high where subsidence

and inversion of temperature do not produce rainfall

Also found on the western margin of continents adjoining cold current like the west

coast of South America

In middle latitudes 35-60* N-S, they are confined to the interior of the continents

where moisture laden winds do not reach e.g. Libya

96. Solution: d)

After arriving in India, Mahatma Gandhi successfully organized satyagraha movements in

various places. In 1916 he travelled to Champaran in Bihar to inspire the peasants to struggle

against the oppressive plantation system.Then in 1917, he organised a satyagraha to support

the peasants of the Kheda district of Gujarat. Affected by crop failure and a plague epidemic,

the peasants of Kheda coul not pay the revenue, and were demanding that revenue

collection be relaxed. In 1918, Mahatma Gandhi went to Ahmedabad to organize a

satyagraha movement amongst cotton mill workers.

97. Solution: d)

Just as the glass in a greenhouse holds the suns warmth inside, atmosphere traps the suns

heat near the earths surface and keeps it warm. This is called natural greenhouse effect

because it maintains the temperature and makes the earth perfect for life. In a greenhouse,

visible light passes through the transparent glass and heats up the soil and the plants. The

warm soil and plants emit infrared radiations. Since glass is opaque to infrared (heat)

radiations, it partly reflects and partly absorbs these radiations. This mechanism keeps the

energy of the sun trapped in the greenhouse. Similarly, carbon dioxide molecules also trap

heat as they are transparent to sunlight but not to the heat radiation.

98. Solution: a)

Self-explanatory. As the total evaporation and moisture content is lesser in the subtropical

and polar areas, winds are dry; and dust particles are more.



99. Solution: b)

http://www.downtoearth.org.in/content/stem-cells-can-heal-damages-caused-parkinson-

s-disease-finds-study

Dopamine (contracted from 3,4-dihydroxyphenethylamine) is

a hormone and neurotransmitter of the catecholamine andphenethylamine families that

plays a number of important roles in the human brain and body. Its name derives from its

chemical structure: it is an amine that is formed by removing a carboxyl group from a

molecule of L-DOPA.

In the brain, dopamine functions as a neurotransmittera chemical released by nerve cells

to send signals to other nerve cells. The brain includes several distinct dopamine systems,

one of which plays a major role in reward-motivated behavior. Most types of reward

increase the level of dopamine in the brain, and a variety of addictive drugs increase

dopamine neuronal activity. Other brain dopamine systems are involved in motor control

and in controlling the release of several other important hormones.

100. Solution: c)

Stem cells are undifferentiated biological cells that can differentiate into specialized cells

and can divide (through mitosis) to produce more stem cells. They are found in

multicellular organisms. In mammals, there are two broad types of stem cells: embryonic

stem cells, which are isolated from the inner cell mass of blastocysts, and adult stem cells,

which are found in various tissues. In adultorganisms, stem cells and progenitor cells act as

a repair system for the body, replenishing adult tissues. In a developing embryo, stem cells

can differentiate into all the specialized cellsectoderm, endoderm and mesoderm

(see induced pluripotent stem cells)but also maintain the normal turnover of regenerative

organs, such as blood, skin, or intestinal tissues.

There are three known accessible sources of autologous adult stem cells in humans:

1. Bone marrow, which requires extraction by harvesting, that is, drilling into bone

(typically the femur or iliac crest).

2. Adipose tissue (lipid cells), which requires extraction by liposuction.

3. Blood, which requires extraction through apheresis, wherein blood is drawn from the

donor (similar to a blood donation), and passed through a machine that extracts the

stem cells and returns other portions of the blood to the donor.

Stem cells can also be taken from umbilical cord blood just after birth. Of all stem cell types,

autologous harvesting involves the least risk. By definition, autologous cells are obtained



from one's own body, just as one may bank his or her own blood for elective surgical

procedures.

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