Chapter-15-Our Enivornment
Class-X
OUR ENVIRONMENT & Biosphere Prepared by : Inderjeet Bhatia
Q1. What is Biosphere?
Ans: Biosphere :- It is the major system which contain all living organisms found on earth called as biosphere. Biosphere is divided into lithosphere, hydrosphere, Atmosphere and life forms.
(a) Lithosphere :- It is the land portion. It has various life present below the surface or on the
surface.(b)Hydrosphere :- It is the region where water is present on earth called as hydrosphere.It is present in the form of snow water vapours, hot water, water present in liquid form. (c)Atmosphere :- It is the gas envelop present around the earth called as atmosphere. It has
various gases in different ratio varying from place to place.
Q2. Give the components of Biosphere with sub-levels?
Ans: Biosphere starts from lowest level.
1.Species:- It is a group of one type of organisms which can interbreed freely among themselves to produce fertile offsprings.
2.Population:-It is the total number of members of a particulars species living in a particular given area.
3.Community :- It is the organism living in a particular area which includes various populations
depending upon each other called as community. It includes interdependent plants and animals.
4.Ecosystem :- It is the interrelationship of living and non-living components of Biosphere operating in a particular area called as ecosystem.
Biotic and Abiotic components:
5.Biome :- It is the ecological group of plants and animals living in a geographically localized area containing various ecosystem. It contain similar plants (flora) and similar animals (fauna).
e.g. Tundra
6.Biosphere :-It is the biggest unit which contain all biomes and all ecosystem operating on earth. It is self-sustaining biological system.
Q3. What is self-sustaining biological system?
Ans: A systematic arrangement of various factors in which some inputs enters, operate various changes and produce various products. When this system is operated without any disturbance between flora, fauna and source of substances. Then it is called as self-sustaining biological system.
Q4. Explain, the factors of ecosystem?
Ans:- Ecosystem :- It is the inter relationship of biotic and abiotic components operating in the various communities called as ecosystem.
(a)Biotic Components or Living Components:- Those components which are living and act in
ecosystem called as living component or biotic component. They must be related with some
relations of food, energy or other materials.
They are of following types :-
1.Producer:- Those organism which produce organic food by raw material in the presence of solar energy and store in the form of chemical energy by the process of photosynthesis called as producer. Therefore, green plants are called primary producer. They are also called as autotrophs or transducer. e.g. grass
2.Consumer :- There are the organisms which depends directly or indirectly on green plant for their food requirement are called as consumer. They are divided into primary consumer, secondary consumer and top consumer. e.g. Deer, good, cow, lion, frogs, grasshopper. They are called as heterotopy.
3.Decomposer :-Those organism which can decomposer complex organic compound into simpler compound so that they can be recycled into the biosphere called as decomposer .e.g. bacteria, fungi.They can make the raw material from various waste substances.
4. Deterivores :- These are various organisms which can break down dead and decaying matter into
simpler compounds by which they can be recycled called as deterivores. e.g. vulture, kite, crows.
(b) Non livings or Abiotic Components :- Those components which does not belong to biotic
community but they constitute from non-living object and climatic factors called as abiotic factors.
1. Climatic factors or physical factor :- Those factors which form climate and varies from place to
place according to geographical condition called as climatic factors like lights, temperature,
pressure, humidity, coldness and also rain.
2. The component factor or the mineral factor :- They constitude the material of biosphere which
include physical environment like soil, water, air, co2, N2, O2, phosphous, sulphur and other
elements.
Q5. What is ecology?
Ans: It is the branch of biology which study the relationship between living with environment also the balancing of ecosystem called as ecology.
Q6. Give the importance of decomposer?
Ans: The decomposer are very important component of biosphere. They convert deed bodies, waste material and other parts of bodies of plants and animals into simple elements and compound so that these materials can enter back into the nutrients pool by which they start recycling into the biosphere. Therefore, they help in the cleaning of environment also fulfill their requirements.
Q7. What is photosynthesis? Why it is important?
Ans: Photosynthesis :- It is the biochemical process of making food using the raw materials like carbon dioxide and water in the presence of sunlight and their chlorophyee by green plants to make organic substances and oxygen called as photosynthesis.
6CO2 + 12H2o C6H12O6 + 6O2 + 6H2O + 114KCAL
Photosynthesis is very important for energy transportation. Only it is responsible for trapping of solar energy and changed it into chemical energy so that the energy become available for biosphere.
Q8. What are consumer? Give their types?
Ans: Consumer: These are non-green plants or other animals which depends an producers called as consumer. Consumer are of six types :
1. Herbivores: Those organism which directly depend upon green plants and consume them as food
called as perbivores e.g. deer, rabbit, goat, grass- hopper , buffalo, cow.
2. Carnivores:- Those animals which depend on the flesh of other animals only called as carnivores.
They are 2nd order consumer. e.g. fox, owls, hawks.
3. Top carnivores :- Those animals which eat herbivores or carnivores and obtain their requirement
from them called as top carnivores. They are 3rd order consumer.
4. Omnivores :- Those animals which depend upon plants and animals both for food called as
omnivores, e.g. cat, mango.
5. Phytoplankton :- Those minute microscopic freely floating organism on the surface of water and
can perform photosynthesis called as phytoplankton. They are autotrophs.
6. Zooplankton :- Those animals which are minute freely floating on water and a depend upon
phytoplankton called as zooplankton. They are hetrotraph.
Q9. What is food chain?
Ans: It is a segvencial arrangement of various organisms in which one consume the other as food to fulfil the energy requirement is called as food chain.
e.g.
(1) Grass Deer Lion
(2) Phytoplankton Zooplankton Small animal & fish Big fish
(3) Algae Small insects Small fish Water Birds.
Q10. Explain, the food chain is unidirectional
Or
The energy flow in a food chain only in one direction?
Ans: In a food chain the solar energy is trapped and changed only. This energy flow into the biosphere through comsumer and decomposer. The herbivores eat green plants and carnivores eat herbivores. Therefore, the solar energy is changed into chemical energy by plants, further in herbivores, finally into carnivores and decomposers. That means the flow of energy is unidirectionals. The energy goes in other form cannot be regain by previous members.
e.g.
Grass Insects Frog Snake Hawk.
Q11. What is trophic level? Explain various trophic levels ?
Ans: Trophic Level : Every member of the food chain through which energy transfer take place called as trophic level. The producer are considered as first trophic level, herbivores second, carnivores third, top carnivores fourth and decomposer are final trophic level.
Q12. Give the lindemens law or ten percent law?
Ans: In the food chain the energy present at producer level move through consumer and decomposer. During the course only ten percent of the energy of previous trophic level can reached into the successive trophic levels remaining energy is changed into other form.
90% changed into other form
eg. Sun Green plants Herbivores Carnivores Top Carnivores
(1%) (10%) (10%)
Therefore, the amount of energy reaches successive trophic level decreases.
Q13. What is food chain web? Why it is effective ?
Ans: Food Web :- It is the net work formed by intermixing various food chain having common trophic level and organisms called ad food web. It is most effective arrangement of food because of more possibilities of food material are there.
Q14. Give the difference of food chain and food web?
Ans:
Food Chain Food Web
1. It is the linear sequence of few 1. It is a network of various sequence
animals. animals.
2. One organism depend only on one 2. One organism depend on more than
one.
3. It is less effective arrangement 3. It is more effective arrangement.
4. Death of one organism destroys 4. Removed or death of one do not cause any effect
whole food chain. on food web.
5. Energy flow is unidirectional 5. Energy flow in many directions.
e.g. Grass deer Lion. e.g. Plants Grasshopper Insects Frog Snake Hawk.
Q15.- What are food pyramid? Give their types?
Ans: Food Pyramid : It is a pyramid like structure formed by keeping a food chain in vertical manners such that the producer remain.
The food pyramid represent :-
1. Quantity of matter present at each trophic level.
2. Number of organisms depending on each other for food at each trophic level.
3. Energy present and reached at each trophic level.
Q16. Why a food chain has not more than fiveth or sixth trophic level?
Ans : In the food chain energy decreases in the ratio of 10:1, Therefore, the energy present at fifth of sixth trophic level is very-very small. Therefore, the member present at that level must consumer very large amount of matter to fulfill their energy requirement, which is also very difficult. Thus, food chain can not have fifth or sixth member.
e.g. Grass Grass Hooper Frog Snake Hawk.
100J 10J 1J 0.1J 0.01J
Q17. Which is better diet and why? Vegetarian and non-vegetarian . Explain with the help of food chain?
Ans: Food Chain :-
VegetableGoatMan (A)
100J 10J 1J
VegetableMan (B)
100J 10J
The vegetarian diet is good because the energy reached on second trophic level is 10 times more than that of third trophic level. In food chain ‘A’ man is present at third trophic level and obtain non-vegetarian food and obtain Joule of energy. In second food chain ‘B’ the man is present at secobd trophic level (vegetarian diet) and obtain 10 Joule which is more than the case of A.
Q18. How does a food chain get shortened ?
Ans: In the food chain if some trophic level become common or intermediate trophic chain get shortened.
e.g.
1. PlantsHerbivores (Omnivore)CarnivoresTop Carnivores
2. Plants OmnivoresTop carnivores.
Food chain also get shortened by reducing the consumer level.
Q19. Give the ultimate source of energy for all organisms?
Ans: Sun is the ultimate source of energy for all organisms.
Q20. Why plants are important components of biosphere?
Ans: Plants can change solar energy into chemical energy which can flow in the biosphere through food chain. Therefore, plants are very important component.
Q21. Give the flow of energy in the biosphere?
Ans: The flow of energy starts from sun in the form of solar energy. This energy is trapped by producer and stored in the form of chemical energy by the process of photosynthesis. About 1% of the total solar energy reached on earth taken by plants. Now this energy move in the biosphere in the form of through food chain. The energy transfer in each step is 10% of the previous level remaining energy is taken by decomposer and done at each trophic level. The energy present in decomposer also change into heat community. Therefore, total energy enter in the biosphere remain constant but move in three directions. In food chain, herbivores, then carnivores, then top carnivores uses this solar energy. This energy is change into decomposer and remaining changed into heat and the processes go on.
Q22. Give the path way of energy?
Ans: the energy path way is only in single direction because the beat form at each trophic level cannot reuse by plants and remaining energy flow to successive trophic level. The energy transformation is never completely efficient. Some energy converted into usable form and remaining into unusable heat. Therefore, the energy transformation is only in one direction.
Q23. Which is better food chain and why?
Ans: The shorter food chain are better because the energy reached at final level is much more higher than that of the energy reached at the final level of bigger food chain according to 10% of law.
E.g. Gross Deer Lion
100J 10J 1J
Grass Rabbit Hiena Lion
100J 10J 1J 0.1J
Q24. What is ecological pyramid? Give their types?
Ans: Ecological Pyramid : The food chain involving various living organism (or species) in a community can be represented graphically by drawing pyramid which are known as ecological pyramid. In these pyramid the producer are kept at bottom. The ecological pyramids can be constructed for a community of organism in an ecosystem representing as :-
(1) Pyramid of numbers
(2) pyramid of mass or biomass
(3) pyramid of energy
Q25. Give the function of food chain?
Ans:
(1) The food chain depicts the structure of living components of an ecosystem of biosphere
(2) Food chain transfer energy and material between the living component.
(3) Food chain controls the number of members of each trophic level and help to maintain ecological
balance.
Q26. How man affect the food chain or ecosystem?
Ans: The activities of man like hunting the hunters cause imbalance in the ecology. The use of machines, chemicals of agriculture like pesticides and fertilizers reduction of forest area may cause high damage to the food chain and create ecological imbalance.
Q27. Give the effect of removal of each member of food chain on chain?
Ans. GrassDeerLion
• If all Lions are removed: It results in increase of numbers of deers. Finally, requiring more food,
heat up all gross then they destroy our crops, resulting whole vegetarian vanish out then all land
change into desert and without food all deer die.
• If all deers are removed : When all deer are removed then the food for Lion is not available. Hence,
their competition cause fighting and reduction in Lion population then lion may eat domestic animal
or human finally in the source of food will decreasing in quantity. Finally, food ends up and all lion
die.
• If all grasses are removed: Grass are at producer level so the energy trapping is not done and
energy become deficient in the biosphere. The herbivores does not obtain food and finished out top
carnivores does not survive and finished out.
Q28. What is biomagnifications of pesticide?
Ans: Bioconcentration of pesticides means accumulation of pesticides in the living organisms like plants, men and animals. Pesticides enter the food chain at the producer level (plant level). The increase in concentration of harmful chemical substances like pesticides in the body of living organisms at each trophic level of a food chain is called bioconcentration.
e.g. (Phytoplankton & zooplankton) Water Algae and protozoa Fish Birds
0.02 ppm of 5 ppm 240 ppm 1600 ppm 2500
harmful chemical chemical chemical harmful chemical
Q29. What are macronutrient and micronutrient? Give examples?
Ans: Macronutrient: Those Mineral elements which are needed in large amount called as
macronutrient. e.g. C, H, O, N, P, K, S.
Micronutrient: Those mineral elements which are needed in small amount called as micronutrient.
e.g. Fe, Mn, Cu, Zn, Ci, Co Mo, B.
Q30. What are biogeochemical cycles? Give their path?
Ans: The circulation of chemical nutrients like carbon, hydrogen, oxygen, nitrogen, phosphorous, calcium and water etc. through the biological and physical world (or biosphere) is known as biogeochemical cycle.
The path of chemicals in cycle passes through :
1. The nutrient pool or sources (from where the nutrient starts).
2. In which form it enters in the biosphere (plant nutrition).
3. In which form it travel on the biosphere (animals, gaseous form).
4. In which form it returns back to the nutrient pool.
Q-1 What is environment? Give its components
Ans: The physical and biological world around us where we live and survive is called as environment.
It has three factors/components:-
1. Physical surroundings:- It includes non-living components like soil ,land ,water bodies & atmosphere or air.
2. Meteorological/Climate factors:- These factors influence the living like sunlight, temperature, rainfall, humidity, pressure, and wind speed.
3. Living components:- Those components which constitute the biotic environment the biotic environment are called as living components. They are plants, animals and microorganisms. They also constitute biological environment.
Q-3 Give the relationship of man with his environment ?
Ans:- Man has very delicate relation with his environment.
ECOLOGY:- It is a branch of biology that deals with the relationship of man & his environment including all type of living forms and non-living components.
ECOLOGICAL IMBALANCE:- By various activities of man, the balance of the atmosphere, lithosphere and hydrosphere is disturbed. Is is done by imbalancing of the cycling of various materials, extra retaining in the components of biosphere. this results in unwanted disappearance of various factors, rise in population of some species and reduction in other. This process is called ecological imbalance. Hence, hunting of carnivores incerease in the population of herbivores and decerease of vegetation.
Accidental leakage of various chemicals & oils
Accidental leakage of Methyl Iso-cyanate (MIC) from Union Carbide on 2nd December 1984 in Bhopal caused death of thousands of people and disabled lakhs.
Accidental leakage of crude oil or petroleum from tankers in seawater causes Oil Slick, which is very dangerous type of pollutions. It kills large number of aquatic animals by disconnecting the supply of air and make large number of birds and animals disabled by depositing oil on their body or body parts.
In English Channel 118000 tone of crude oil was leaked accidentally by Torreycanyon ship and to remove this slick 2 million liters of detergent was used to clear it which caused further pollution.
URBANIZATION:- Urbanization causes removal of forests, covering of land by various types of houses. The formation of cities require transportation, raw materials for construction, food for people living there and other related substances can causes all types of pollution.
INDUSTRIALIZATION:- Modern lifestyle increases the dependence on industries. Therefore the growth in population causes rapid increase in industries. This results in increase in pollution of air, water and land along noise pollution. The requirement of raw material increases the on-land resulting in various types of mining (open or closed) shifting of natural biota and displacement of native species.
Some types of atomic and radioactive industries cause very dangerous waste. So industrialization causes major ecological imbalance.
Human Activities:- The activities like bathing, washing clothes, excretion, use of chemical, foaming agents, cooking fuels, various types of fibers like synthetic fibers may disturb the ecological balance.Various settlements along the riverside cause pollution in the river. The most affected settlement is that which is the lowermost in the stream.
Q-4 How soil replenishment takes place ?
Ans:- The soil be maintained according to its nutrients level and fertility but it is decreased by monoculture (growing one type of crop again and again). Therefore various steps must be taken to increase agricultural production along with replenishment of soil. It is done by:
1. Crop Rotation
2. Field Fallow
3. Mixed and Multiple cropping
4. Balanced use of fertilizers and pesticides
.
Q-9 Give the factors affecting biological bodies or biota or size of population.
Ans:- The components which can influence the living are categorized into three factors:
1. Physical surrounding.
2. Living organisms
3. Meteorological/Climatic factors
Factors affecting population of species in a given area
1. Availability of food material and other requirements related to food.
2. Availability of living space or shleter or domain.
3. Intra-species competition
4. Intra-species competition or predation
(a) Availability of abiotic factors
(b) By the influence of natural calamity like draught, flooding, epidemic and earthquake.
Q-10 Give the effect of unplanned technological growth on environment or abiotic factors?
Ans:- Unplanned technological growth causes following effects:-
A. Excessive excavation/Utilization of natural resources like Air, Water, Soil.
B. Excessive use of fossil fuels and polluting agents.
C. Depletion of ozone layer with the use of CFCs and aerosols.
D. Excessive use of chemicals like pesticides (Biomagnification) and fertilizers.
E. Excessive use of forests or deforestation.
F. Excessive use of various metals by excessive mining of ores.
G. Excessive use of nuclear power plants.
Unplanned technology led to influence in other biotic & abiotic factors.
Q11. Give the ill effects of fossil fuels ?
Ans:- When fossil fuels are used then varoious types of pollutants are released.
1. When coal is burnt out, then CO2 (Green-House effect), CO (Suffocation), SO2 (Acid Rain), ashes like Fly Ash (Darkening of buildings), CFCs (Ozone Hole).
2. Use of Oil (Crude Oil & Petrol) gives CO2 (Green house effect), CO (Suffocation), Hydrocarbons (Blackening of bodies), Photochemical smog, Oxides of sulphur & Nitrogen (Acid Rain), Photochemical Process (Ozone Hole), Lead (Lead Poisoning).
Q14 Explain an example of Unplanned Technological growth and its ill effcets?
ORHow Aswan Dam is useful as well as harmful ?
Ans:- When Aswan Dam was built on River Nile in 1957, then purpose was:
To prevent annual flooding of the river.
To prevent enough water for irrigation throughout the year and hence increase the agricultural output.
Generate electricity by hydro-electric power plants for rapid development of industries and related technical growth.
Along this useful aspects, ill aspects were created by this unplanned growth:
The quality of soil decreases, the fertility is lost because the actual flooding enriches the soil by annual nutrient rich silt.
The excessive use of chemical fertilizers requires them to put high power chemical industries. Thus pollution level rises.
The large numbers of canals for irrigation were formed which increased the salt content of nearby areas and thus decreased the productivity (decrease fertility and product).
The annual production of Sardine fish reduced by 97% because barriers controlled various pathways of water. Thus, they remained in the dam. Increase in population in a particular area.
The final effect was the displacement of native species and numerous villages from flooding zone.
Q15. Why wildlife is necessary 9based on Predators/Carnivores) ?
Ans:- predators (Carnivores) are very important components for environment and ecological balance. They can control the population of Herbivores and provide food to smaller carnivores or detrivores. Thus the food chain remains balanced overpopulation of species doesn't occur as well as nutrient pool is f\refilled E.g. Snake eats up rats and other rodents. Thus protecting the food crops and stored food grains. Thus prevent excessive loss.
Q-16 Give various wildlife protection steps ?
Ans:-To control the decreasing population of predators and other wildlfe, we should observe:
a. Proper ban on all types of hunting (poaching).
b. Proper legislations are made to control illegal activities of poaching.
c. Providing knowledge to all members of society for the importance of wildlife along their natural beauty life.
d. By making various protected areas like National Parks and Sanctuaries.
e. By issuing particular animal to particular big industrial groups for protection.
f. By preservation of reproductive cells of all types of wildlife to maintain the gene poof.
Q17 Give the examples of wildlife sanctuaries and related animals?
Ans:- Following are the examples of wildlife sanctuaries and related animals.
a. Jim Corbett National Park: Tiger.
b. Sunderban Sanctuary: Bengal Tiger.
c. Kanha Sanctuary: Rhinoceros.
d. Gir Sanctuary: Lion
e. Bharatpur Bird Sanctuary: Water Birds.
f. Ranthambore National Park: Mainly cheetah
Q18. What do you understand by environmental planning ?Give its components.
Ans: Environmental planning is the step taken for judicious use of environment by taking administrative and legislative measures to control pollution of an aspects with proper ecological balance.
The main components are conservation of natural resources like Ground Water, Forest, fossil fuels, minerals and ores along with the physical change. this is done by:
1. Using recycling of substances like paper, wood and other industrial waste.
2. Increasing the forest area or planting of plants is advised for good occasions.
3. To maintain Water Cycle by preventing pollution or filtration.
4. Preventing soil erosion and using barren land for cultivation purposes.
5. Controlling various cycles by judicious use of each component.
6. Less use of fossil fuels and more use of non-conventional sources.
Q19 What are waste substances ? Give its basic types and examples ?
Ans:- Various types of substances produced in industries (as left over), in homes, in fields or in plants (Industrial Plants) after obtaining the actual product are called as waste products.
Types:-
1. Biodegradable Waste:-Those waste materials which can be decomposed by bacteria or other microorganisms so that they can be recycled and reused in nutrient pool, msn can use them to obtain other useful things are called biodegradable substances. E.g. animal waste, agricultural waste, parts of plants & animals, and various types of food materials. Positive uses: These materials can be used to obtain Biogas, related substances, Artificial Bricks, Paper, Decorative Articles, visiting cards and other materials.
2. Non-Biodegradable Waste:- Those waste material, which cannot be decomposed by any type of microorganisms or biological agents into simpler substances or their natural recycling is not possible are known as Non-Biodegradable Waste. E.g. Pesticides, plastics, polybags, Empty Refills, Fibers, Glass, Metal Objects, Foils, Nails and Radioactive Waste
7 Give safe methods of waste substances disposal /one is better to save an environment “Reuse” or “Recycling”? Give reasons to support your answer.
Ans. “Reuse” of material is better than “Recycling” in saving our environment because:
1Reuse of material does not use any energy, whereas recycling uses some energy.. In reuse things are used again and again instead of throwing away.The 3 R’s to a more sustainable future But we need not feel powerless or overwhelmed by the scale of the problems because there are many things we can do to make a difference. You must have come across the three R’s to save the environment: Reduce, Recycle and Reuse. What do they refer to? Reduce: This means that you use less. You save electricity by switching off unnecessary lights and fans. You save water by repairing leaky taps. You do not waste food.
2. Recycle: This means that you collect plastic, paper, glass and metal items and recycle these materials to make required things instead of synthesizing or extracting fresh plastic, paper, glass or metal. In order to recycle, we first need to segregate our wastes so that the material that can be recycled is not dumped
3 Reuse: This is actually even better than recycling because the process of recycling uses some energy. In the ‘reuse’ strategy, you simply use things again and again. Instead of throwing away used envelopes, you can reverse it and use it again. The plastic bottles in which you buy various food-items like jam or pickle can be used for storing things in the kitchen.
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What is the ozone layer? |
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The ozone layer is a deep layer in the stratosphere, encircling the Earth, that has large amounts of ozone in it. The layer shields the entire Earth from much of the harmful ultraviolet radiation that comes from the sun. |
Q22What is Biomagnification of pesticides or Bioconcentration? How is it caused? Explain with a suitable aquatic food chain occurring in 1982? How is it dangerous to human beings?
Bio-magnification;-The industrial wastes, the chemicals used as pesticides and fertilizers are washed into water. They contain toxic substances like cadmium, lead, copper etc, these materials are harmful for health. The plants along with the water and minerals absorb these materials, some of the materials are taken by the aquatic animals and plants. By this way it enters the food chain. When these materials reach the human body directly with contaminated food or indirectly by way of plants and other animals. The concentration of the toxic material increases at each trophic level in the ecosystem. This is called Bio magnification or biological concentration.