TAMIL
NADU OPEN
UNIVERSITY
School
of Computer Science
SPOT
ASSIGNMENT (CY-2013/AY 2012-2013)
NOTE
: Part A Contains 3
Questions and will carry 5 Marks each, Part B Contain 1 Question and will carry
10 Marks. Students are requested to write 150 words and should not exceed 2
pages each in Part A, 300 words and should
not exceed 4 pages in Part B. Refer
TNOU Materials.
Bachelor
of Computer Applications
Second Year
Course Code : CCE
Course Title : ENVIRONMENTAL STUDIES
(Total Marks=25)
Part-
A- Short Answer Questions
Answer all questions (3 X 5 = 15 Marks)
1. Explain the various components of
natural resources.
Answer:
Natural resources occur naturally
within environments that exist relatively undisturbed by humanity, in a natural
form. A natural resource is often characterized by amounts of biodiversity and
geodiversity existent in various ecosystems.
• Potential Resources – Potential
resources are those that exist in a region and may be used in the future. For
example, petroleum may exist in many parts of India, having sedimentary rocks
but until the time it is actually drilled out and put into use, it remains a
potential resource.
• Actual Resources – Actual resources are
those that have been surveyed, their quantity and quality determined and are
being used in present times. The development of an actual resource, such as
wood processing depends upon the technology available and the cost involved.
• Reserve Resources – The part of an
actual resource which can be developed profitably in the future is called a
reserve resource.
• Stock Resources – Stock resources are
those that have been surveyed but cannot be used by organisms due to lack of
technology. For example: hydrogen.
Renewable
resources are ones that can be replenished naturally. Some of these resources,
like sunlight, air, wind, etc., are continuously available and their quantity
is not noticeably affected by human consumption.
Non-renewable
resources are resources that form extremely slowly and those that do not
naturally form in the environment. Minerals are the most common resource
included in this category. By the human perspective, resources are
non-renewable when their rate of consumption exceeds the rate of
replenishment/recovery; a good example of this are fossil fuels, which are in
this category because their rate of formation is extremely slow (potentially
millions of years), meaning they are considered non-renewable.
2. Explain the various components of
ecosystem.
Answer:
An
ecosystem is a community of living organisms (plants, animals and microbes) in
conjunction with the nonliving components of their environment (things like
air, water and mineral soil), interacting as a system.] These biotic and
abiotic components are regarded as linked together through nutrient cycles and
energy flows.As ecosystems are defined by the network of interactions among
organisms, and between organisms and their environment, they can be of any size
but usually encompass specific, limited spaces (although some scientists say
that the entire planet is an ecosystem).
Energy,
water, nitrogen and soil minerals are other essential abiotic components of an
ecosystem. The energy that flows through ecosystems is obtained primarily from
the sun. It generally enters the system through photosynthesis, a process that
also captures carbon from the atmosphere. By feeding on plants and on one
another, animals play an important role in the movement of matter and energy
through the system. They also influence the quantity of plant and microbial
biomass present. By breaking down dead organic matter, decomposers release
carbon back to the atmosphere and facilitate nutrient cycling by converting
nutrients stored in dead biomass back to a form that can be readily used by
plants and other microbes.
3. Define the following
a. “Food Web”
b. Green house effect
Answer:
Food Web:
A food web (or food cycle) depicts
feeding connections (what-eats-what) in an ecological community and hence is
also referred to as a consumer-resource system. Ecologists can broadly lump all
life forms into one of two categories called trophic levels: 1) the autotrophs,
and 2) the heterotrophs. To maintain their bodies, grow, develop, and to
reproduce, autotrophs produce organic matter from inorganic substances,
including both minerals and gases such as carbon dioxide. These chemical
reactions require energy, which mainly comes from the sun and largely by
photosynthesis, although a very small amount comes from hydrothermal vents and
hot springs. A gradient exists between trophic levels running from complete
autotrophs that obtain their sole source of carbon from the atmosphere, to
mixotrophs (such as carnivorous plants) that are autotrophic organisms that
partially obtain organic matter from sources other than the atmosphere, and
complete heterotrophs that must feed to obtain organic matter. The linkages in a
food web illustrate the feeding pathways, such as where heterotrophs obtain
organic matter by feeding on autotrophs and other heterotrophs. The food web is
a simplified illustration of the various methods of feeding that links an
ecosystem into a unified system of exchange. There are different kinds of
feeding relations that can be roughly divided into herbivory, carnivory,
scavenging and parasitism. Some of the organic matter eaten by heterotrophs, such
as sugars, provides energy.
Green house effect:
The greenhouse effect is a process by
which thermal radiation from a planetary surface is absorbed by atmospheric
greenhouse gases, and is re-radiated in all directions. Since part of this
re-radiation is back towards the surface and the lower atmosphere, it results
in an elevation of the average surface temperature above what it would be in
the absence of the gases.
If an ideal thermally conductive
blackbody was the same distance from the Sun as the Earth is, it would have a
temperature of about 5.3 °C. However, since the Earth reflects about 30%of the
incoming sunlight, this idealized planet's effective temperature (the
temperature of a blackbody that would emit the same amount of radiation) would
be about −18 °C. The surface temperature of this hypothetical planet is 33 °C
below Earth's actual surface temperature of approximately 14 °C. The mechanism
that produces this difference between the actual surface temperature and the
effective temperature is due to the atmosphere and is known as the greenhouse
effect.
Part- B- Long Answer Question
Answer the following question (1 X 10 = 10
Marks)
- a. Discuss the various legal measures to prevent the environmental
pollution.
b. India as a mega
biodiversity country – Discuss.
Answer:
a)
Pollution
prevention (P2) describes activities that reduce the amount of pollution
generated by a process, whether it is consumer consumption, driving, or
industrial production. In contrast to most pollution control strategies, which
seek to manage a pollutant after it is formed and reduce its impact upon the
environment, the pollution prevention approach seeks to increase the efficiency
of a process, thereby reducing the amount of pollution generated at its source.
Although there is wide agreement that source reduction is the preferred
strategy, some professionals also use the term pollution prevention to include
Pollution Prevention With the ever-rising human population, pollution has
become a great concern. Pollution from human activities is a problem that does
not have to be inevitable. With a comprehensive pollution prevention programme,
most pollution can be reduced, reused, or prevented. The purpose of this paper
is to introduce a pollution prevention programme that will demonstrate how to
stabilize the population growth as well as how to reduce and manage waste to
prevent further pollution to the planet. Human Population Numbers With nearly
seven billion people in the world, and the fact that the average person
produces 4.4 pounds of waste each day, around a ton of waste every year, it is
easy to see why pollution is such a huge problem (Recycling Revolution, 2010).
In order to slow the growing levels of pollution, the human population needs to
stabilize. Population numbers are rapidly increasing in developing countries.
It is estimated that “the human population will increase by one billion people
in the next decade” The math is staggering when you add a ton a waste per
person per year. Growth in these developing countries is partly due to
developing countries governments telling their citizens that more numbers are
needed to fill in the open spaces as the West has More people equals more
natural resources used and waste created. The human population growth is the
largest environmental problem the world faces. Slowing the Population Growth
What can be done to slow the human population growth? “Experience shows that
the most effective ways to slow human population growth are to encourage family
planning, to reduce poverty, and to elevate the status of women Such plans and
strategies can be converted into policies to ensure sustainability. “Action
plans and strategies can be developed to increase public understanding of how
rapid population growth limits chances for meeting basic
b)
India as a mega biodiversity country –
Discuss.
India is one of the 12
mega biodiversity countries in the world. The country is divided into 10
biogeographic regions. The diverse physical features and climatic situations
haveformed ecological habitats like forests, grasslands, wetlands, coastal and
marine ecosystems and desert ecosystems,
which harbor and sustain immense biodiversity.
Biogeographically,
India is situated at the tri-junction of three realms - Afro-tropical, Indo-Malayan
and Paleo-Arctic realms, and therefore, has characteristic elements from each
of them. This assemblage of three distinct realms makes the country rich and unique
in biological diversity.
The country is also
one of the 12 primary centres of origin of cultivated plants and domesticated
animals. It is considered to be the homeland of 167 important plant species of
cereals, millets, fruits, condiments, vegetables, pulses, fibre crops and oilseeds,
and 114 breeds of domesticated animals.
Hot- spots of Biodiversity
A
biodiversity hotspot is a biogeographic region with a significant reservoir
of
biodiversity that is threatened with destruction.
An
area is designated as a hot spot when it contains at least 0.5% of plant
species as
endemic.
There
are 25 such hot spots of biodiversity on a global level, out of which two are
present
in India.
These
are:
⇒ Indo-
Burma (earlier The Eastern Himalayas) and
⇒ The
western Ghats & Sri Lanka
These
hot spots covering less than 2% of the world’s land area are found to have
about
50% of the
terrestrial biodiversity.
