IGNOU Free Solved Assignments Course Code: BEVAE-181 Assignment Code: BEVAE-181/TMA/2019-2020

Course Code: BEVAE-181
Assignment Code: BEVAE-181/TMA/2019-2020
Maximum Marks: 100
Note: Attempt all questions. The Marks for each question are indicated against it.
Q. 1. (a) Explain the importance of environment in day to day life by citing suitable examples in about 120 words.
Ans. Whatever type of environment organisms inhabit, they all need of life supporting elements for their survival. These include that they breathe, food and water they take in, and shelter either as natural like caves and tree holes or as artificial dwellings (like houses). Environment is the only source that provides these life supporting elements.
For example, human make use of the land for cultivating crops, soil provides nutrients needed for the growth of plants. The land form determines the soil types found in any one area and soil itself varies from place to place. Some soils are rich in nutrients and other are lacking in them. The soils lacking nutrients need the addition of fertilizers. Climate and short term weather changes are characterized mainly by wind, temperature, pressure and rainfall and are determined by properties of the atmosphere.
(b) “Sustainable development is a goal toward which all human societies need to be moving.” Elaborate the statement in about 120 words.
Ans.Sustainable development is an ideal which no societies today have achieved anything resembling it. Nevertheless, as with justice, equality, and freedom, it is important to uphold sustainable development as an ideal – a goal toward which all human societies need to be moving. For example, policies and actions that reduce infant mortality, increase the availability of family planning, improve the air quality, provide more abundant and pure water, preserve and protect natural ecosystems, reduce soil erosion and reduce the release of toxic chemicals to the environment, all move a society in the right direction toward a sustainable future.
Q. 2. Differentiate between the following terms by giving suitable examples in about 120 words:
(a) Primary succession and secondary succession.
Ans. There are difference between primary succession and secondary succession of ecological succession.
Primary succession is initiated when a new area that has never previously supported an ecological community is colonised by plants and animals. These could be an newly exposed rock surfaces from landslides or lava flows. Primary succession thus, occurs where no community exists before, such as rocky outcropping, newly formed deltas, sand dunes, emerging volcano islands and lava flows. Whereas secondary succession occurs when a community in an area is drastically disturbed leading to its destruction which results in a new community moving into that area. Secondary succession is more common than primary succession and is often the result of natural disasters such as fires, floods, and winds, as well as human interference such as logging and tree-cutting.
(b) Direct and Indirect use value of biodiversity.
Ans.There are differences between direct use values of biodiversity and indirect use of biodiversity. Direct use of values are those goods that are ensured directly, that is, food and timber, Maintaining a wide range of components of biological diversity can be of direct use, especially in the fields of agriculture, medicine and industry. Direct use can involve the use of forests, wetlands or other ecosystems for timber extraction, collection of non-timber products, fishing etc.
Whereas, indirect use value is for those services that support the items that are consumed. For example, non-consumptive value, aesthetic value, cultural and religious values, ethical values etc. Non-consumptive use value is concerned with nature’s services which also make vital contribution to our society. Aesthetic value or aesthetic aspect of biodiversity is reflected in the trouble people take to maintain their home gardens, people visit national park etc.
Q. 3. Answer the following questions in about 150 words.
(a) What is biodiversity hotspot? Why is India considered as a mega biodiversity hotspot?
Ans. Bio-diversity hot spots are areas that are extremely rich in species, have high endemism and are under constant threat.
India is considered as one of the mega bio-diversity hotspot in the world, and the causes for this are given below : -
1) Four hot spots out of thirty four global bio-diversity hotspots are in India with its neighbouring countries.
2)  The endemics of India bio-diversity are high. About 33% of the recorded flora is endemic to the country. Of the 49,219 plant species, 5,150 are endemic and distributed into 141 genera under 47 families corresponding to about 30% of the world’s recorded flora.
3) India has 26 recognised endemism centres that are home to nearly a third of all the flowering plants identified and described to date in the country.
4) India has two major realms called the Palacretic and the Indo-Malayan and three biomes that is tropical humid forests, tropical deciduous forests and the warm deserts or semi-deserts.
5)  India has ten bio-geographic regions.
6)  India is one of the twelve centres of origin of cultivated plants.
(b) Distinguish between Biota of the Pelagic and Benthic zones of the Oceans with examples.
Ans. There are differences between Biota of Pelagic zone and Benthic zone of ocean. Pelagic region constitutes ninety percent of the total ocean surface and is less rich in species and numbers of organisms that biota of littoral zone and biota of the heretic oceanic zone.
The most abundant pelagic phytoplankton’s are still the dinoflagellates and diatoms which are the chief photosynthetic feeders, others are carnivores. Sea cucumbers and sea urchins crawl on the floor eating detritus and bacteria and serve as food for the carnivorous brittle stars and crabs.
Whereas, biota of benthic zone of ocean forms the floor of the ocean. Organisms here are heterotrophic Rooted animals are sea lilies, sea fan, sponges etc. Snails and clams remain embedded in mud while starfish, sea cucumbers and sea urchins move on its surface.
(c) Differentiate between the surface and ground water. Describe the factors responsible for degradation of water.
Ans. There is difference between ground water and surface water. Water which falls in the form of precipitation moves down into soil and threw rocks and gets accumulated as ‘ground water.’ The layer of rock through which it percolates down is known as ‘aquifer’ and water can be utilized by digging out wells. Ground water can be found in two layers of the soil.
Whereas, the surface water includes the streams, ponds, lakes, human-made reservoirs and canals, and freshwater wetlands. As part of water cycle the surface water bodies are considered renewable resources though they are dependent on other parts of water cycle.
These are certain factors that are responsible for degradation of water and they are – contamination of water bodies like rivers, oceans etc. due to pollution created by intensive agriculture, urbanization, industrialization and deforestation.
(d) Write a short note on global carbon cycle with the help of diagram.
Ans. Some carbon in our atmosphere enters a long term cycle referred to as “Global Carbon Cycle” in which carbon accumulates in the form of organic matter in the peaty layers of bogs and moorlands or as insoluble carbonates (for example, the insoluble calcium carbonate (CaCO3) of various sea shells) in bottom sediments of aquatic systems. This sedimentary rocks such as lime stone and dolomite. The following diagram describes it :-

As in the above diagram, in deep oceans such carbon can remain buried for millions of years till geological movement may lift these rocks above sea level. These rocks may be exposed to erosion, releasing their carbon dioxide, carbonates and bicarbonates into streams and rivers. Hard water has usually flowed through limestone at some point, picking up carbonates which they accumulate as ‘fur’ in kettles when the water is boiled. Fossil fuels such as coal, petroleum and natural gas are also part of the carbon cycle which may release their carbon compounds that were buried before they could be  decomposed and were subsequently transformed by time and geological processes into solid or liquid hydrocarbon fuels. When fossil fuels are burned the carbon stored in them is released back into the atmosphere as CO2.
Q.4.How does forest support ecological system and moderate global climate? Explain with suitable examples in about 250 words.
Ans. Forest is one of the largest available renewable resources on the planet earth. Forest support ecological system and function such as moderate global climate. Forest performs certain activities which are crucial for supporting ecological systems and processes directly which are given below :-
a)  Forests check the soil erosion by preventing the action of wind and water thereby preserves the fertile top soil.
b)    It prevents landslides and reduces the intensity of cyclones and floods.
c)  By preventing soil erosion, forests reduce silting of water bodies including reservoirs.
d)   Forest improves air quality by absorbing toxic gases and particulate matter.
e)    It protect watersheds and ensure perennial supplies of fresh water.
Moderation of global climate :- Forests stabilize global climate in a significant matter by influencing natural cycles such as hydrological and carbon cycles. Spatial as well as temporal patterns of rainfall are greatly influenced by forest. How much of water is retained in the soil, and how much flows away, sometime causing floods, also depends on tree cover. Similarly forest can also influence the atmospheric carbon-dioxide level. Tree biomass holds carbon-dioxide in a fixed state. Therefore, forest acts as a major source of carbon sink, that is, ability to absorb carbon-dioxide from the atmosphere. In other words, a carbon sink is a natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period. When wood is burnt CO2 is released in the atmosphere. This has a direct impact on the extent of greenhouse effect and global warming. In other words, more forests lead to greater removal of atmospheric carbon-dioxide during photosynthesis resulting reduction of the greenhouse gases in the atmosphere. Therefore, large scale a forestation has been adopted as a measure to reduce greenhouse effect.
Q.5.“India has tremendous potential in non-conventional sources of energy.” Elucidate the statement with suitable examples and arguments in about 250 words.
Ans. India has tremendous potential in non-conventional sources of energy. Our diverse geographical settings help in promotion of non-conventional energy. Sources of energy namely solar, wind and tidal.
a) Solar energy :- Solar energy is the most readily available abundant source of energy. It is free as it does not belong to anybody. It is non-polluting. Solar energy in India can be used directly to give us hot water during winter, or run a refrigerator in summer.
b)  Wave and tidal energy :- Energy can be obtained from waves and tides. These waves and tides are another source of energy which is perpetual and can be harnessed for generating electricity, particularly where sea water can move into Energy carried by water has also been widely used in India’s hilly regions, since a wheel with pedals can be made to turn when it is put in a fast flowing stream. Flour mills of small size built on this principle were used in Kashmir for a long time. In fact large “hydroelectric” power stations work on the same principle. A natural or artificial water fall is made to turn a modern kind of pedal wheel, called a turbine, which upon rotation generate electricity.
In India, the first project with a capacity of 150 MW wave energy has been set up at Vizhinjam near Thiruvananthpuram. A major tidal wave power project costing 5,000 crores is proposed to be set up in the Hanthal creek in the Gulf of Kachin in Gujarat. 
c)  Wind Energy :- Wind energy has been used for hundreds of years for sailing, grinding grain, and for irrigation. Wind energy systems convent the kinetic energy associated with the movement of air to more useful forms of power. Wind turbines transform the energy in the wind into mechanical power.
So, the above mentioned non-conventional sources of energy help India in developing the future of the nation.
Q. 6. Explain the following terms in about 50 words:
(a) Ecofeminism.
Ans. Ecofeminism is radically a new vision. It is rooted in women’s biological, procreative and maternal role. Ecofeminism finds instant rapport with Eastern concepts of ‘Mother Nature’. The ecology of nature is linked to the biology of women’s bodies, and the exploitation of nature to the exploitation of women’s wombs.
(b) Agenda 21.
Ans. A non-binding action plan of the United States with regards to sustainable development. The ‘21’ in Agenda 21 refers to 21st Century.
(c) Global Warming.
Ans. Heating of earth’s atmosphere due to increasing concentration of carbon-dioxide and other greenhouse gases.
(d) Hazardous Wastes.
Ans. A waste is considered hazardous if it has only one of the following characteristics :- ignitability, corrosiveness, reactivity, radioactivity and toxicity.
Q. 7. Answer the following questions in about 150 words.
(a) How does Land filling act as an important method of waste disposal? Explain.
Ans. The disposal of hazardous waste by land filling is an important method of disposal in many countries. Land filling means underground storing of harmful substances. This involves hauling the refuse to an area allocated for this purpose. In India, such areas range from unsanitary ‘open dumps’ to properly operated ‘sanitary land fills’. Open dumps are poor method of waste disposal because they cause environmental problems. For example, they can ruin the appearance of an area and provide a home for rats and other rodents who spread disease. If garbage is exposed, it rots and smells foul. Most dumps allow some burning, which fills the surroundings with smoke. In addition, rain water can drain through refuse and carry harmful substances to streams.
(b) What is Acid rain? Describe its effect.
Ans. Toxic gases like Sox and Nox dissolve in rain water to form sulphuric acid and nitric acid and come down as acid rain. Acid rain is regarded as an environmental issue, which threaten a lives on earth.
Effects of Acid rain:-
There are many damaging effects of such acid rain and they are given below :-
Effect on Crops and Plants :-The acid rain has detrimental effects on crops and forests. The acid rain can dissolve important minerals and nutrient present in the soil. Soil bacteria and fungi that play important role in nutrient cycling and nitrogen fixation are also affected. Thus, soil fertility is reduced and plant growth is affected.
Effect on Water Bodies and Aquatic life :-Water bodies like lakes, rivers and ponds are also affected by the acid rain. The accumulation of acid in them over a period of time lowers the Ph and affects the aquatic plants and animals. Many aquatic plants and different types of fish have different tolerance levels for such conditions and hence, cannot survive.
Effect on Human Health :- The gases responsible for the acid rain and the acids present in acid rain can affect human health especially the lungs and the respiratory system. They dry dispositions from air can cause heart and lung problems such as asthma and bronchitis.
Effect on Materials :- Acid rain also damages bridges, buildings, statues and monuments. It can cause corrosion of metals and plants.
(c) Describe issues emerges in enforcement of national environment legislations.
Ans.The basic problems in enforcement of national environment legislation in India are given 
below :-
1)After an analysis of all enactments and provisions at national level. It is to be noted that nature of most of the existing environmental legislations are essentially punitive not preventive. Only once the chemicals or substances are discharged into the air or water or soil does the act apply. The preventive measures have hardly ever evoked or worked and the concerned agencies have moved into action only after the harm has been done.
2) More serious problem in the implementation of environmental legislation is overlapping powers of authorities involved in supervising the safety mechanism and devices of companies, and in granting or refusing No objection certificate (NOC).
3)   In some cases statutes of environmental legislations do not lay down any guidelines on the nature of authority and their specific rights and the obligations.
4) A common feature with environmental legislation in India is that they exclude peoples’ participation in their implementation.
5)   Sometimes enforcement of legislation is difficult due to insufficient fund.
(d) What is environment ethics? Why do we need a set of ethics for the environment? Explain.
Ans. Environmental ethics is referred as a discipline that studies the moral relationship of human beings, and also the value and moral status of the environment and its non-human contents.
We need set of environmental ethics for the following three factors :-
1)   New effect on nature :- As our modern technological civilization affects nature greatly we must examine the ethical consequences of these new technological actions.
2) New knowledge about nature :- Modern science demonstrates as to how we changed and are in the process of changing our environment in ways not previously understood, thus raising new ethical issues.
3) Expanding moral concerns :- Some people argue that animals, trees, and even rocks have normal and legal rights. These expected concerns lead to a need for a new ethic.
Q.8.“Habitat destruction is recognized as most significant threat to global biodiversity?” Elucidate the statement in present context with suitable examples in about 250 words.
Ans. Habitat destruction is recognised today as the most significant threat to global biodiversity and bears responsibility for much of the species loss worldwide. This includes :-
a)  Felling of forests for land use (that is clear felling for development, agriculture) large scale logging and small scale patchwork agriculture. Shifting cultivation alone is believed to be responsible for 70% of deforestation in Africa, 50% of deforestation in Asia and 35% of forest loss in the America.
b)    Destruction of Mangrove site for aqua-culture.
c)     Mining and destruction of corals.
d)     Conversion of wetlands for land uses.
e)    Over-extraction of timber and fuel wood.
f)   Human-induced burning of habitats (that is forest firing for shifting cultivation and firing grasslands to improve fodder for cattle.
g)   Damming of rivers.
h)  Siltation and sedimentation of freshwater bodies.
i) Pollution also disturbs the natural habitat considerably. Industrial wastes cause severe impact, particularly on aquatic habitats. For example, during 1950s and 1960s, insecticides particularly chlorinated hydrocarbons (such as DDT), reduced the population levels of several birds as the bald eagle and brown pelican).
Q.9.Differentiate between the primary and secondary pollutants. Explain how these pollutants are harmful for human and environment in about 250 words.
Ans. There are difference between primary and secondary pollutants. Primary Pollutants are emitted directly into the air as a result of natural or human activity. Examples include – sulphur dioxide, nitrogen oxides, carbon-dioxides, carbon-monoxide, hydrocarbons and particulates released from fuel burning.
Whereas secondary pollutants are produced as a result of chemical reactions between primary pollutants and normal atmospheric compounds under the influence of electromagnetic radiations from the sun. For example, the primary pollutant sulphur dioxide (SO2) reacts with oxygen (O2) in the atmosphere to form sulphur trioxide (So3), a secondary pollutant.
Effect of Primary and Secondary pollutant on human and environment. SO2 or oxides of sulphur, for instance can effect on human by causing acid rain; corrosion of paints, metals and injury or death to animals and plants. Another pollutant CO2 has a major role in green-house effect, produces weak carbonic acid adding to acid rains; co affect human health by binding to hemoglobin, which may result in Asphyxia.
Q.10.Critically analyse a case of people’s movement in India against environmental degradation in about 300 words.
Ans. People’s movement plays a very important role in environmental protection in our country. One such movement is Chipko movement in the Himalayan region in India. From the last nineteen century, the Himalayan Forests, have been subject to rapid exploitation. This large-scale destruction has lead to severe ecological problems in upper Alkananda Valley, people also resented the conversion of natural forests into monoculture plantation.
To check environmental degradation in this region, voluntary organisations like the Gangotri Gram Swarajya Sangha (GGSS) in Uttarkashi and Dasholi Gram Swarajya Mandal (DGSM) in Gopeshwar started Chipko Movement in the 1970s. Environmentalists like Chandi Prasad Bhatt and Sunderlal Bahuguna led Chipko movement in Garhwal Himalayas’.
Chipko means to hug the tree. Volunteers in their attempt to stop commercial felling threatened to hug trees if they saw came near them. Their activities popularized the movement through folk songs, street plays and widespread campaign. Its slogan was “What do the forest bear? soil, water, pure air, are the basis of life”.
As a result of the struggle, the Government replaced the contractor system and formed Uttar Pradesh Forest Department Cooperation (GDFDC) and the forest related activities were encouraged through local cooperatives. In 1981, as a response to Sunderlal Bahuguna’s indefinite past, the Government constituted an eight member expert committee to prepare a comprehensive report to the Himalayan forest policy. The government later put a fifteen year moratorium on commercial tree felling in the Uttarakhand Himalayas.

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