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Abiotic components - class-VI

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I. Temperature
II. Humidity
III. Vegetation 
The abiotic factors of ecosystem include

  1. I only

  2. II only

  3. III only

  4. I and II only

  5. I, II and III


Correct Option: D
Explanation:

Biotic factors of an ecosystem include all plant and animal species present in there. The abiotic factors include a physical environment in which they can survive. It includes light, temperature, humidity and other climatic condition as well as physical factors like soil. Thus, the correct answer is D. 

Pedology is the science of

  1. Rocks

  2. Diseases

  3. Soil

  4. Pollution


Correct Option: C
Explanation:

Pedology is the study of soils in their natural environment. It is one of the two branches of soil.

The part of the biosphere which contains soil is known as 

  1. Pedosphere

  2. Lithosphere

  3. Hygrosphere

  4. Toposphere


Correct Option: A
Explanation:
  • Pedosphere is an outer layer of earth that contains soil.
  • Lithosphere includes the brittle upper portion of the mantle, crust and Mantles are made of rock or ices. 
  • Hydrosphere contains all the waters on the earth's surface, such as lakes and seas.
  • Troposphere is the lowest layer of the atmosphere, closest to the earth's surface. so option A is a correct answer.

In a .......... ecosystem, the producers are mostly herbaceous or woody plants.

  1. Terrestrial

  2. Aquatic

  3. Desert

  4. None of these


Correct Option: A
Explanation:

Herbaceous plants are plants with very flexible stems. Woody plants include trees and shrubs. These are the plants present in the terrestrial ecosystem. They convert solar energy into chemical energy through photosynthesis in which carbon dioxide and water are used in presence of sunlight to synthesize nutrients such carbohydrates in the form of glucose and release oxygen into the atmosphere. Since plants form the base of the terrestrial ecosystem they are the producers.

Environment consists of

  1. land, air, water

  2. light, temperature and rainfall

  3. plants, animals and microbes

  4. All the above


Correct Option: D
Explanation:
The environment consists of two major components:
  • Abiotic components: These are non-living components of the environment and consist of two things, materials and energy (that may be light or chemical energy). Materials include land, air, water, minerals, salts, atmospheric gases, rainfall, temperature etc.
  • Biotic components: These are living components of the environment and divided into autotrophic and heterotrophic components. An autotrophic component is the producers or green plants while heterotrophic component includes consumers (primary, secondary and tertiary consumers) and decomposers (microbes).
Hence, all the given options are correct.
So, the correct answer is 'All the above'.

Which of the following components of biosphere makes an interface with the soil?

  1. Pedosphere

  2. Troposhere

  3. Atmosphere

  4. Stratosphere


Correct Option: B

Which of the following gas is present at a very high concentration in our environment?

  1. $O _{2}$

  2. $CO _{2}$

  3. $H _{2}$

  4. $N _{2}$


Correct Option: D

At any given time,  __________ of the earth is illuminated by the sun.

  1. One-fourth

  2. One-third

  3. One-half

  4. Two-thirds


Correct Option: C

Which ecosystem is important in purifying air, recycling water and controling climate?

  1. Man subsidized solar power ecosystem

  2. Fuel power ecosystem

  3. Naturally subsidized solar powered ecosystem

  4. Unsubsidized natural solar powered ecosystem


Correct Option: A

Edaphic factors are related to 

  1. Humidity

  2. Soil texture

  3. Rainfall

  4. Wind velocity


Correct Option: B
Explanation:
  • Various environmental factors can be divided majorly into climatic factors, edaphic factors and biotic factors.
  • The factors which relate to structure and composition of soil are called edaphic factors. Soil composition, organic matter, soil water, soil air and soil organisms are examples of edaphic factors.
  • Humidity, rainfall and wind velocity are climatic factors.
  • Examples of biotic components include animals, plants, fungi, and bacteria.
  • So the correct option is B.

If there was no CO$ _2$ in the earth's atmosphere, the temperature of earth's surface would be 

  1. As such

  2. Less than the present level

  3. Increase from present level

  4. Dependent upon oxygen amount of the environment


Correct Option: B
Explanation:

Carbon dioxide is a greenhouse gas. It has the ability to trap sunlight and thus causes the increase in the temperature of Earth surface. If the situation on the Earth was with a lesser amount of $CO _2$, the temperature would have been very little. More pollution will cause the release of more $CO _2$ to the atmosphere causing global warming. 

Due to the increased average global temperature on fish populations, the fish will show
I. Movement from saline to fresh waters
II. Movement to deeper waters
III. Movement to higher latitudes

  1. I only

  2. II only

  3. III only

  4. I and II

  5. II and III


Correct Option: E
Explanation:

Limited or no sunlight in deeper waters keep the temperature lower in the regions making it suitable for fishes when surface water become warm due to increasing in average global temperature. Likewise, higher latitudes maintain lower temperatures due to the angle of irradiance. Salinity does not affect the temperature range of water bodies. Thus, the correct answer is E.

There is no atmospheric reservoir in

  1. Carbon cycle

  2. Water cycle

  3. Phosphorus cycle

  4. Sulphur cycle


Correct Option: C
Explanation:

The abiotic components which are recycled without any involvement of the gaseous form are known as the sedimentary cycle. The element is present in the form of salts as rocks in the geosphere which is taken up by the plants and then transferred to the animals. The phosphate is generally transferred and used in the form of ATP by the living cells. There is no form of phosphorus present in the atmosphere.

Thus, the correct answer is option C. 

The phosphorus cycle differs from those of carbon and nitrogen as well as from those of sulphur, oxygen and hydrogen in that it lacks 

  1. Water

  2. Dust particles

  3. Gaseous phase

  4. All of the above


Correct Option: C
Explanation:

The abiotic components which are recycled without any involvement of the gaseous form are known as the sedimentary cycle. The element is present in the form of salts as rocks in the geosphere which is taken up by the plants and then transferred to the animals. The phosphate is generally transferred and used in the form of ATP by the living cells. The remaining abiotic components including sulphur, carbon, oxygen and hydrogen. 

Thus, the correct answer is option C. 

The asteroid which is believed to have collided with earth some 65 million years ago is

  1. Apollo

  2. Vesta

  3. Ceres

  4. Gaspra.


Correct Option: D

Which statements regarding response of organisms to abiotic factors in false?

  1. All birds and mammals are capable of thermoregulation

  2. Majority of animals and nearly all plants cannot maintain a constant internal environment

  3. Shivering is a kind of exercise which produces heat and raises body temperature

  4. Very small animals are commonly found in polar regions as they have to spend less energy to generate heat

  5. Diapause is a stage of suspended development seen in zooplankton


Correct Option: D

Select incorrect statement :

  1. Orchid epiphytic on Mango is commensal

  2. Bird laying eggs in the nest of another for incubation shows brood parasitism

  3. Most animals and plants maintain a constant internal temperature

  4. Small animals are rare in polar regions

  5. One species harmed, other unaffected in amensalism


Correct Option: C

The lowest temperature of any land mass of the universe was recorded in

  1. North America (1949)

  2. Mt. Everest, Himalayas (1954)

  3. Antarctica (1982)

  4. Siberia (1947)


Correct Option: D
Explanation:

The Siberian city of Yakutsk is the coldest in the world. It was -89.8$^0$C temperature in 1947. Coldest Temperature in North America was -62.8$^0$C in 1949. The temperature of Mt. Everest, Himalayas in 1954 was -36$^0$C. Antarctica's lowest temperature was recorded in 1982 and was -89.2$^0$C. 

Thus, the correct answer is option D.

Which one of the following is not a correct match of the term and its description?

  1. Ecosystem - Functional unit of nature

  2. Global ecosystem - Entire biosphere

  3. Aquatic ecosystem - Wetland

  4. Natural ecosystem - Crop field


Correct Option: D
Explanation:

Crop field is considered as man-made(anthropogenic or artificial) ecosystem. Natural ecosystem is developed in nature without human involvement, e.g., forest, ocean, etc.

The abiotic components of the environment are the living factors.

  1. True

  2. False


Correct Option: B
Explanation:
There are two major components of an ecosystem:
  • Abiotic components: These are non living components of environment and consist of two things, materials and energy (that may be light or chemical energy). Materials include water, minerals, salts, atmospheric gases etc.
  • Biotic components: These are living components of environment and divided into autotrophic and heterotrophic components. Autotrophic component is the producers or green plants while heterotrophic component includes consumers (primary, secondary and tertiary consumers) and decomposers.
Hence, the statement given in the question is incorrect.
So, the correct answer is 'False'. 

Which of the following is an ecosystem service provided by a natural ecosystem?

  1. Cycling of nutrients

  2. Prevention of soil erosion

  3. Pollutant absorption and reduction of the threat of global warming

  4. All of the above


Correct Option: D
Explanation:

The products of ecosystem processes which have environmental aesthetic and indirect economic value are named as ecosystem services. Soil formation and soil protection are the major ecosystem services accounting for nearly 50% of their total worth. Plant cover protects the soil from drastic changes in temperature. There is little wind or water erosion as soil particles are not exposed to them. The soil remains spongy and fertile. There are no landslides and no floods. The plant cover of natural ecosystem absorbs polluting gases, causes settling of suspended particulate matter, removes CO2 and releases O2. Purified air becomes available. There is no overall depletion of nutrients as the same as repeatedly circulated and recirculated. This keeps the fertility of soil intact.

So, the correct answer 'All of the above'.

The minimum temperature in the sea is .......... , while in freshwater ponds it never goes below ..........

  1. -3$^o$C, 0$^o$C

  2. -10$^o$C, -4$^o$C

  3. 20$^o$C, -10$^o$C

  4. 25$^o$C, -100$^o$C


Correct Option: A
Explanation:

The temperature of the surface waters varies mainly with latitude. The polar seas (high latitude) can be as cold as -2 degrees Celsius (28.4 degrees Fahrenheit), while the Persian Gulf (low latitude) can be as warm as 36 degrees Celsius (96.8 degrees Fahrenheit).
Temperature varies in ponds and lakes seasonally. During the summer, the temperature can range from $4^0$C near the bottom to $22^0$C at the top. During the winter, the temperature at the bottom can be $4^0$C, while the top is $0^0$C (ice).

Thus, the correct answer is option A.

Aquatic and terrestrial animals need sulphur and nitrogen to

  1. Grow

  2. Transpire

  3. Evaporate

  4. Photosynthesis


Correct Option: A

Scientists are able to determine the air temperature in the thermosphere by:

  1. Using radiosondes

  2. Using temperature probes in orbiting satellites

  3. Observing changes in satellite orbits

  4. Direct measurements in manned, high-altitude balloons


Correct Option: C

Initial causes of ecological succession includes:

  1. Climatic and Biotic factors

  2. Abiotic Factors

  3. Water Vapours

  4. Air Precipitation


Correct Option: A

Ecotype is a type of species in which environmentally induced variations are

  1. Temporary

  2. Genetically fixed

  3. Genetically not related

  4. None of the above


Correct Option: B

Non living things in an environment is known as

  1. Biotic Factors

  2. Abiotic Factors

  3. Biotic and abiotic factors

  4. All of above


Correct Option: B

Which of the following is not properly matched?

  1. Formaldehyde- Carcinogenic

  2. Sulphur dioxide - Respiratory problems

  3. Nitrogen oxide - Brown air

  4. Mean annual temperature - $25^o$C

  5. Photochemical smog - Grey air


Correct Option: D
Explanation:

Mean annual temperature is calculated by subtracting the lowest recorded temperature from the highest recorded temperature of the of the day. It can vary depending on the weather and climate of an area.

A. Formaldehyde has been classified as cancer causing agent by the EPA. It has shown leukaemia incidences.
B. Sulphur dioxide is responsible for the respiratory tract diseases like asthma, bronchitis etc.
C. Nitrogen oxide is called the brown air because of the change in frequencies of absorption of light when nitrogen combines with the oxygen.
D. Mean annual temperature can vary depending on the weather and climatic conditions.
E. Photochemical smog forms grey air due to the formation of ozone and PAN that decreases the visibility.
Hence, the correct answer is 'Mean annual temperature - 25$^{o}$C'

In what way a plant growing on a forest floor is adapted for its survival?

  1. Has shallow roots

  2. Requires low light

  3. Has a deep ta root

  4. Requires strong light

  5. Requires moist soil


Correct Option: B
Explanation:

Plants growing on the forest floor (understorey) are adapted to lower Sunlight intensity or are shade loving. This is because, the dense canopy does not allow enough light to penetrate through and reach the forest floor. Light is the limiting factor for these plants and therefore, they are adapted to survive under low light conditions. Moisture availability and related adaptations are not of consideration. Thus, the correct answer is option B.

The ultimate energy source of all ecosystems is?

  1. Producers

  2. Organic molecules

  3. Carbohydrate

  4. Solar radiation


Correct Option: D
Explanation:

 The Sun is the major source of energy for organisms and the ecosystems of which they are a part. Producers such as plants, algae, and cyanobacteria use the energy from sunlight to make organic matter from carbon dioxide and water. This establishes the beginning of energy flow through almost all food webs. The continual input of energy, mostly from sunlight, sustains the process of life. Sunlight allows plants, algae and cyanobacteria to use photosynthesis to convert carbon dioxide and water into organic compounds like carbohydrates. This process is the fundamental source of organic material in the biosphere. The overall productivity of an ecosystem is controlled by the total energy available.

So the correct option is 'solar radiation'.

Out of the total proposed cost of various ecosystem services, cost of climate regulations and habitat for wildlife are.

  1. $50\%$

  2. $10\%$

  3. $6\%$

  4. $25\%$


Correct Option: C
Explanation:

Robert Constanza and his colleagues have put the value of ecosystem services to $33$ trillion dollars a year. Out of which $50\%$ is proposed for formation of soil, prevention of flood and mitigating droughts. The value of $10\%$ each for nutrient cycle and recreation and $6\%$ for climate regulation and habitat preservation for wild flora and fauna has been proposed.

Edaphic factor refers to.

  1. Water

  2. Soil

  3. Relative humidity

  4. Altitude


Correct Option: B
Explanation:

Edaphic factors are classified under the abiotic factors affecting an ecosystem. Edaphic factors include factors of soil, e.g., soil texture, substratum, topography, mineral composition, pH, etc. These factors can influence the distribution and interrelationships of organisms, as well as rate of decomposition.

Life arose in

  1. Soil

  2. Fresh water

  3. Marine water

  4. Air


Correct Option: C
Explanation:

We know that the environment we live in is made up of 2 components, namely living (biotic) and non-living (abiotic). Different theories were proposed to study the origin of the wife. But they lead to the conclusion that life had originated on earth in seawater and marine organisms were one of the first to emerge. In earth's early atmosphere, there was no ozone layer, thus the UV rays of the sun could directly reach the earth. As living organisms cannot survive UV radiation directly, many scientists believed that life originated in aquatic habitats. Apart from this, different requirements of these early organisms were also fulfilled in the deep-sea vents. 

Thus, option C 'Marine Water' is the correct option.

Terrestrial life would become impossible with

  1. Disappearance of moon

  2. Decrease in mean annual temperature by $10^o C$

  3. Change in orbit of earth

  4. Change in atmosphere permitting all solar radiations to reach lithosphere


Correct Option: D
Explanation:

The total amount of solar radiation reaching to the lithosphere do not enter the surface of the earth as it would heat up the earth making it unsuitable for any life. Therefore, 35% of the solar radiation are reflected back to the space.

So, the correct answer is option D.

The source of energy in an ecosystem is

  1. Sun

  2. Decayed bodies

  3. Green plants

  4. Sugar


Correct Option: A
Explanation:

Every living being on planet earth gets energy directly from the sunlight. Plants use it to manufacture food and other animals use the food manufactured by plants.

All of these are examples of abiotic factors except 

  1. Mushrooms 

  2. Soil type

  3. Average yearly rainfall

  4. Sunlight

  5. Relative humidity


Correct Option: A
Explanation:
The environment is a complex of many factors which surround an organism. These factors are known as environmental factors or ecological factors which may be either living or biotic and non-living or biotic. 
Biotic factors include plants, animals, microbes etc.
Abiotic factors are the non-living factors, substances, and conditions of the environment which influence the physiology, survival, function, and reproduction of organisms. These factors are divided as:
1. Direct factors- For example, light, temperature, humidity of the air, soil air, soil water, soil nutrients etc.
2. Indirect factors- For example, soil structure, soil organisms, altitude, wind, slopes etc.
Hence, Mushrooms will be included under biotic factors and soil type, average yearly rainfall, sunlight and relative humidity will be included under abiotic factors.
So, the correct answer is 'Mushrooms'.

Which of the following is not a property of water?

  1. It becomes more dense when it freezes.

  2. It dissolves molecules in the air.

  3. It absorbs heat when the hydrogen bonds break.

  4. It forms hydrogen bonds with other water molecules to create surface tension.

  5. It form hydrogen bonds with other molecules by adhesion.


Correct Option: A
Explanation:
A. When water freezes, it is converted into ice. Ice has a cage like structure and thus, its density is less than water. Hence, water becomes less dense when it freezes.
B. Water is a polar solvent and thus, many gases are soluble in water. Hence, it dissolves molecules in the air.
C. Water has high energy hydrogen bonds. When these bonds break, heat is released which is absorbed by the water due to its high specific heat capacity.
D. Surface tension is interaction between water molecules which results due to formation of hydrogen bonds between water molecules.
E. Adhesion is the force of attraction between different molecules. Water can form hydrogen bonds with other molecules and this is called adhesion.
Hence, statement A is incorrect.
So, the correct answer is 'It becomes more dense when it freezes'.

All of these are considered ecosystem services except

  1. Water purification

  2. Nutrient cycling

  3. Crop pollination

  4. Waste decomposition

  5. None of the above


Correct Option: E
Explanation:
The benefits obtained from ecosystem are considered as ecosystem services.
A. As the polluted and wastewater flows through wetlands and forests, it gets filtered and cleaned naturally.
B. Pollination is the transfer of pollen grain from anther to the sigma. Pollinators such as bees, butterflies, birds etc. aid in pollination.
C. Waste decomposition is the breakdown of complex organic materials into simpler ones by the action of microorganisms (detritivores).
D. Nutrient cycling is the exchange and movement of organic matter within the ecosystem.
So, the correct answer is 'All of the above'.

Which of these is an example of an abiotic factor?
I.    Crickets
II.   Rainfall
Ill.  Shark

  1. I only

  2. II only

  3. III only

  4. I and III only

  5. I, II and III


Correct Option: B
Explanation:
Abiotic factors are the non living factors, substances and conditions of the environment which influence the physiology, survival, function, behaviour and reproduction of organisms. The major abiotic factors are temperature, water, light and soil. 
Hence among all the options given in the question, rainfall is the abiotic factor while crickets and sharks are included under biotic factors as they are living factors.
So, the correct answer is 'II only'.

Which is not a natural ecosystem?

  1. Desert

  2. Aquarium

  3. Forest

  4. All of the above


Correct Option: B

Which of the following is a climatic factor?

  1. Oxygen

  2. Temperature

  3. Soil structure

  4. Altitude


Correct Option: B
Explanation:

The constituents of the environment, which directly or indirectly influence the form and functioning of organisms in any specific way are known as environmental factors. They are of two types: abiotic and biotic. 

The abiotic factors are of four types-
  1. Climatic (light, air, temperature, humidity, precipitation)
  2. Edaphic (soil)
  3. Topographic (surface behaviour of earth)
  4. Fire 
Therefore, the correct answer is option B.

If all the plants of the world die, all the animals will also die due to shortage of

  1. Cold air

  2. Oxygen

  3. Timber

  4. None of the above


Correct Option: B
Explanation:
Plants maintains the balance of oxygen and carbon dioxide in the atmosphere. The plants perform photosynthesis and releases oxygen. The oxygen released by the plants is taken by the animals which is used for breakdown of food and release energy. If all the plants will die the animals will also die due to shortage of oxygen.
So, the correct answer is option B.

Source of energy in ecosystem is

  1. Sun

  2. ATP

  3. Sugar made by plants

  4. Green plant


Correct Option: A
Explanation:

The source of energy in an ecosystem is the sun. The solar energy is trapped by green plants and converted into biologically useful form i.e., carbohydrates. All the consumers depend either directly or indirectly on green plants for nutrition. The energy flow in an ecosystem is always unidirectional i.e., solar radiation to producers to herbivores to carnivores.

Which of the following is present in maximum amount in atmosphere?

  1. Oxygen

  2. Nitrogen

  3. Carbon dioxide

  4. Hydrogen


Correct Option: B
Explanation:
By volume, dry air contains about 78% nitrogen, 21% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases
So, the correct answer is 'Nitrogen'

Which of the following is a source of energy to an ecosystem?

  1. Solar energy

  2. Sugar stored

  3. Heat liberated during respiration

  4. ATP


Correct Option: A
Explanation:

In an ecosystem, green plants trap solar energy and convert it into sugars which are utilised by all the living organisms and also passed on to successive trophic levels. Thus, the correct answer is option A.

In an ecosystem of abiotic components which of the following occur?

  1. Flow of energy

  2. Cycling of materials

  3. Consumers

  4. Flow of energy and cycling of materials


Correct Option: B
Explanation:

In an ecosystem plants produces their own food by utilising solar energy, water and carbon dioxide, which is then transfer to the successive trophic levels. Some of the minerals are locked in living systems as constituents of protoplasm. These minerals are returned to environment through the decomposition of death and decay of organisms.Thus, the correct answer is option B.

Which one of the following components of ecosystem comes from outside?

  1. Oxygen

  2. Temperature

  3. Insects

  4. Energy


Correct Option: D
Explanation:

In an ecosystem, the ultimate source of energy is the sun. The solar energy is trapped by producers and converted to usable biochemical compounds like carbohydrates. These carbohydrates are passed on successively to higher trophic levels. Thus, the correct answer is option D.

Source of energy in ecosystem is

  1. Sun

  2. Sugar produced in photosynthesis

  3. Green plants

  4. ATP


Correct Option: A
Explanation:

An ecosystem consists of living things like producers, consumers and decomposers and nonliving things like air, water, land. The ultimate source of energy in an ecosystem is sun. The plants in presence of sunlight synthesize its food. From plants, the energy is transferred to primary consumers and secondary consumers and decomposers. 

The correct answer is 'Sun.'

Pick the odd one out
Natural gas, Sun, Bio-mass, Wind.

  1. Natural gas

  2. Sun

  3. Bio mass

  4. Wind


Correct Option: A
Explanation:

Natural gas is a non-renewable source of energy that is made of hydrocarbons, primarily methane. Its usage is subjected to the exhaustion because its formation takes time. Sun, biomass wind are the renewable sources of the energy. Their usage does not result in their exhaustion.

Hence, the correct answer is 'Natural gas'

Which of the following is most ecologically relevant factor ?

  1. Precipitation

  2. Temperature

  3. Soil

  4. Wind


Correct Option: A
Explanation:
Precipitation is any form of a liquid or solid water particles that falls from the atmosphere and reach the surface of the earth. Its effect deflect the temperature, wind and humidity. 
So the correct answer is 'Precipitation'.

Read the following statements and choose the correct set of option w.r.t. ecosystem.
I. Various ecosystem are interconnected by flow of energy and transfer of materials.
II. It is self sustained and self regulated segment of nature.
III. Energy flow is always cyclic while flow of nutrients is unidirectional.
IV. Density of ecosystem is governed by degree of biogeochemical cycling and the amount of nutrients.

  1. I, II and IV are correct

  2. I, II and III are correct

  3. Only III is are correct

  4. III and IV are correct


Correct Option: A

Identify which is not correct?

  1. Age of Universe -$20$ Billion years

  2. Age of Earth - $4.5$ Billion years

  3. Life appeared on earth - $500$ million years

  4. Both a & b


Correct Option: A

The earth is tilted at an angle of $23.5^{o}$  with respect to the plane of its orbit around the sun. If the amount of tilt were increased to $40^{o}$, we would expect in middle latitudes:

  1. Hotter summers and colder winters than at present

  2. Cooler summers and milder winters than at present

  3. Hotter summers and milder winters than at present

  4. Cooler summers and colder winters than at present


Correct Option: A

In the stratosphere, the air temperature normally:

  1. Decreases with increasing height

  2. Increases with increasing height

  3. Both increases and decreases depending on the season

  4. Cannot be measured


Correct Option: B

Sunlight that bounces off a surface is said to be __________ from the surface.

  1. Radiated

  2. Absorbed

  3. Emitted

  4. Reflected


Correct Option: D

One third of sunlight striking earth and its atmosphere is reflected back to

  1. Space

  2. Air

  3. Troposphere

  4. Stratosphere


Correct Option: A

Sunlight passes through a thicker portion of the atmosphere at

  1. Sunrise

  2. Noon

  3. Sunset

  4. Both a and c


Correct Option: D

In which ecosystem sun is main source of energy?

  1. Fuel power ecosystem

  2. Man subsidized solar power ecosystem

  3. Unsubsidized natural solar powered ecosystem

  4. Naturally subsidized solar powered ecosystem


Correct Option: D

Mangroves and estuaries, less dependent on

  1. Animals

  2. Sunlight

  3. Inorganic

  4. Organic factors


Correct Option: B

The creating force of any ecosystem is

  1. Organic fuels, carbohydrates

  2. Biomass

  3. Solar energy

  4. Producers


Correct Option: C
Explanation:

Nearly all of the energy, that drives ecosystems ultimately comes from the sun. 

Solar energy, which is an abiotic factor, enters the ecosystem through the process of photosynthesis. The organisms in an ecosystem, that capture the sun's electromagnetic energy and convert it into chemical energy are called as producers. 
Producers include all of the green plants and some bacteria and algae. The primary consumers exclusively feed on producers. They are known as herbivores. Primary consumers only obtain a fraction of the total solar energy about 10% captured by the producers they eat. 
The other 90% is used by the producer for growth, reproduction, and survival, or it is lost as heat. Primary consumers are eaten by secondary consumers. Secondary consumers are eaten by tertiary consumers. 

Ecosystem has two components. They are

  1. Plants and animals

  2. Trees and fungi

  3. Living and nonliving

  4. Frogs and man


Correct Option: C
Explanation:

An ecosystem is made up of components, biotic and abiotic. Biotic components constitute all the living members of an ecosystem. While abiotic component of an ecosystem consists of non-living substances and factors such as air, water soil, sunlight etc. Thus option C is the correct answer. 

Soil erosion can occur due to

  1. Rains or floods

  2. High velocity winds

  3. Deforestation

  4. All the above


Correct Option: D
Explanation:

Soil is made up of many layers, forming soil profile. The uppermost layer of soil is made up of sandy soil that withers away quickly under the effect of blowing wind, flowing water in the form of rains or floods. Apart from this, trees hold the soil particles together with the help of their roots. Deforestation activities lead to a decrease in the number of trees resulting in an increase in the rate of soil erosion.

So, option D "All of the Above" is the correct answer.

Which of the following occurs in abiotic component of ecosystem?

  1. Flow of energy

  2. Cycling of materials

  3. Consumers

  4. Flow of energy and cycling of materials


Correct Option: D
Explanation:

Flow of energy and consumers are part of biotic components of ecosystem. Water, carbon, nitrogen and phosphorous all take paths from the non-living environment to living organisms, such as trees and then back to non-living environment. These paths known as biogeochemical cycles. In these cycles, a pathway is formed when a substance enters into living organisms, stays for a long time, then returns to the non-living environment. As it is part of abiotic component of ecosystem.

Therefore, the correct answer is option B.

Primary source of energy in an ecosystem is

  1. Sugar stored in plants

  2. Heat liberated during respiration

  3. Solar energy

  4. Heat liberated during fermentation


Correct Option: C
Explanation:

The fundamental source of energy in almost all ecosystems is radiant energy from the sun. The energy of sunlight is used by the ecosystem's autotrophic, or self-sustaining, organisms. Consisting largely of green vegetation, these organisms are capable of photosynthesis - i.e., they can use the energy of sunlight to convert carbon dioxide and water into simple, energy-rich carbohydrates. The autotrophs use the energy stored within the simple carbohydrates to produce the more complex organic compounds, such as proteins, lipids, and starches, that maintain the organism's life processes. Organic matter generated by autotrophs directly or indirectly sustains heterotrophic organisms. Heterotrophs are the consumers of the ecosystem; they cannot make their own food. 

Therefore, the correct answer is option C.

Which one of following word is related to Homo sapiens

  1. Herbivore

  2. Carnivore

  3. Omnivore

  4. Autotroph


Correct Option: C
Explanation:

Human beings (Homo sapiens) are omnivores. People eat plants, such as vegetables and fruits. We eat animals, cooked as meat or used for products like milk or eggs. We eat fungi such as mushrooms. We also eat algae in the form of edible seaweeds such as nori, which are used to wrap sushi rolls, and sea lettuce is eaten in salads. Bears are omnivores, too. They eat plants like berries as well as mushroom (fungi) and animals like salmon or deer.

Therefore, the correct answer is option C.

Soil is affected by

  1. Wind

  2. Rainfall, temperature

  3. Light and humidity

  4. All of these


Correct Option: D
Explanation:

The flow of wind and its rate affects the rate of soil erosion. Rainfall governs the amount of groundwater available to the soil. Temperature also affects the constitution of soil. The amount of sunlight and humidity in the air also affect the type of soil and characteristics of soil particles. 

So, option D is the correct answer.

The main factor for determining the distribution and abundance of eukaryotic extremophiles is

  1. Temperature

  2. Water availability

  3. Location

  4. Abundance of food


Correct Option: D
Explanation:
Eukaryotic extremophiles inhabit areas where there exists a source of food or energy. They however are not found in high temperature (>/= 70$^0$C) and deep subsurface areas or areas of high pressure
So, the correct answer is 'Abundance of food'

Which of the following is most important abiotic factor in pond ecosystem?

  1. Water

  2. Phythoplankton

  3. Zooplankton

  4. Temperature


Correct Option: A
Explanation:

Abiotic factor means the non living chemical or physical parts of the ecosystem. So, considering that only water and temperature are the abiotic components out of all the given options. Since, pond is the ecosytem here, water is the most important abiotic factor, because pond is essentially made of up water. If water isnt present no pond ecosytem will exist.

Maximum contribution of $O _2$ is from

  1. Phytoplankton

  2. Grasslands

  3. Herbs and shrubs

  4. Dense forest


Correct Option: A
Explanation:

In nature, major source of liberation of oxygen is photosynthesis. Photodissociation liberates oxygen from water during the process of photosynthesis. Phytoplanktons are the most abundant photosynthesizers in nature.

The reservoir pool for gaseous cycles of matter is ____________.

  1. Atmosphere

  2. Hydrosphere

  3. Both (a) and (b)

  4. Lithosphere


Correct Option: C
Explanation:

In gaseous cycles of matter the materials involved in circulation between biotic and abiotic components of biosphere are gases or vapours and the reservoir Pool is atmosphere or hydrosphere. e.g $N _2$,$CO _2$ and $H _2O$ So, the correct answer is 'Both (a) and (b)'

Edaphic factors are related to 

  1. Soil

  2. Man

  3. Animals

  4. Temperature


Correct Option: A

Which one of the following is not an edaphic factor ?

  1. Mineral matter

  2. Organic matter

  3. Rainfall

  4. Soil water


Correct Option: C

Ultimate source of energy for living beings is

  1. Carbohydrates

  2. Fats

  3. Sunlight

  4. ATP


Correct Option: C
Explanation:

A food chain is series of plants/animals which are interrelated in the form of organism being eaten as food by the other. It consists of producers, consumers and decomposers. It always starts with photosynthesis as plants are producers. The ultimate source of energy for living beings is sunlight. The plants in presence of sunlight synthesize its food. From plants, the energy is transferred to primary consumers and secondary consumers and decomposers. The animals eating plants are called as primary consumers and animals eating primary consumers are called as secondary consumers. 

The correct answer is 'Sunlight.'

The driving force for an ecosystem is

  1. Biomass

  2. Producers

  3. Carbohydrates in producers

  4. Solar energy


Correct Option: D
Explanation:

Ecosystem is made up of living and nonliving things. Living things or biotic things include plants and animals. Nonliving things or abiotic things include air, water, land.  It is composed of organisms interacting within communities. The driving force for an ecosystem is solar energy. Plants use solar energy to synthesize their food by the process of photosynthesis. From solar energy, the energy is transferred to plants and other organisms via plants.

Thus, the correct answer is 'Solar energy.'

Multinational source of energy is

  1. Soil

  2. Water

  3. Sun

  4. All the above


Correct Option: C
Explanation:
  • The sun is made up of about 80% hydrogen, 20% helium and only 0.1% other elements. 
  • Sun is the most important source of energy. The sun is the source of life on our planet Earth and, directly or indirectly, is the fuel for most renewable systems. Photovoltaic and solar thermal systems, as well as solar thermal power stations, convert solar irradiation directly into useable energy.
  • Hence Multinational source of energy is the sun.
  • So, the correct answer is 'Sun'.

Choose the correct answers from the alternatives given :
What is the source of the energy that flows through the living world?

  1. Photosynthesis

  2. Chemical bonds

  3. Sun

  4. Green plants


Correct Option: C
Explanation:

Sun is the ultimate and major source of energy which is required and fulfills the need of the world. photosynthesis and chemical bonds are performed and formed respectively by the sunlight due to which all the necessary reactions occur leading to the completion of all the processes. Green plants require sunlight to produce organic food in which water and gases mix with sunlight to produce their food.

So, the correct option is ' Sun'.

Who of the following are the ultimate sources of energy for carnivorous organisms in the food chain of a forest ecosystem?

  1. Sun

  2. Photosynthetic species

  3. Herbivorous species

  4. Decomposer species


Correct Option: A
Explanation:

For all organisms, the sun, or solar radiation, is the ultimate source of energy. Plants are primary producers of energy from the sun. Plants use sun, chlorophyll, water, carbon dioxide and nutrients to manufacture glucose, an alternate form of energy

So, the correct option is 'Sun'.

Rainfall pattern depends on

  1. The underground water table

  2. The number of water bodies in an area

  3. The density pattern of human population in an area

  4. Prevailing season in an area


Correct Option: A
Explanation:

The Rainfall pattern depends on the number of water bodies in an area because which area has more water bodies that area evaporates more water and this evaporation increases the precipitation water cycle and hence initiate  the rainfall 

So option 'b' the number of water bodies in an area is the correct answer. 

Migration in birds is guided in part by-

  1. Celestiial navigation

  2. Temperature chnages

  3. Territorial aggression

  4. All of the above


Correct Option: A
Explanation:

Birds that nest in the Northern Hemisphere tend to migrate northward in the spring to take advantage of burgeoning insect populations, budding plants and an abundance of resting locations. This is guided by celestial navigation with a sextant.

So, the correct option is 'Celestial navigation'.

Low clouds retard surface cooling at night better than clear skies because:

  1. The clouds absorb and radiate infrared energy back to earth

  2. The water droplets in the clouds reflect infrared energy back to earth

  3. The clouds start convection currents between them

  4. The clouds are better conductors of heat than is the clear night air


Correct Option: A

If a glass of water were surrounded by saturated air:

  1. The level of the water in the glass would slowly decrease

  2. The water's temperature would slowly increase

  3. The level of the water in the glass would not change

  4. The water's temperature would slowly decrease


Correct Option: C

The primary source of energy for the earth's atmosphere is:

  1. Energy from within the earth

  2. The sun

  3. Erupting volcanoes

  4. Lightning discharges associated with thunderstorms


Correct Option: B

If you want to keep an object cool while exposed to direct sunlight,

  1. Put it inside a brown paper bag

  2. Wrap it in black paper

  3. Wrap it in aluminum foil with the shiny side facing inward

  4. Wrap it in aluminum foil with the shiny side facing outward


Correct Option: D

The lag in daily temperature refers to the time lag between the:

  1. Time of maximum solar radiation and the time of maximum temperature

  2. Time of minimum temperature and the time of maximum solar radiation

  3. Minimum and maximum temperature for a day

  4. Minimum and maximum solar energy received at the surface for a given day


Correct Option: A

What are sources of energy an ecosystem rely on?

  1. Wind energy

  2. Sunlight and Chemical energy

  3. Thermal Energy

  4. Wave energy


Correct Option: B

In which ecosystem sun energy is replaced by highly concentrated potential energy of chemicals and fuels?

  1. Man subsidized solar power ecosystem

  2. Unsubsidized natural solar powered ecosystem

  3. Naturally subsidized solar powered ecosystem

  4. Fuel power ecosystem


Correct Option: D

Water logged soils are generally 

  1. Physiologically dry

  2. Physiologically wet

  3. With great amount of water

  4. With less amount of water


Correct Option: A
Explanation:

If all the air spaces of soil are filled with water, the condition is known as water logging of soil. Such soils are physiologically dry soils

Therefore, the correct answer is option A

Solar radiations heat up

  1. Land faster than the water bodies

  2. Land slower that the water bodies

  3. Equally both land and water bodies

  4. Neither land nor water bodies.


Correct Option: A
Explanation:

Solar radiation is radiant energy emitted by the sun. The land being darker and less reflective will absorb great deal of solar radiation and will have significant increase in temperature.

Which one of the following is biotic in origin?

  1. Texture and porosity of soil

  2. Rainfall

  3. Carbon dioxide content of soil

  4. Light intensity


Correct Option: C
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