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1. Living World |
Can you recall?
1. What is the difference between living and non-living things?
2. Enlist the characters of living organisms.
— Living
organisms show movement and locomotion.
— They
need energy (food) for survival.
— They
give responses to the external as well as internal stimuli.
— They
exhibit reproduction.
— They
exhibit growth, development, ageing and death.
3. Whether all organism are
similar? Justify your answer.
— No.
— Because,
they show diversity in different aspects.
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e.g.
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Size and shape – microscopic bacteria to
gigantic whale.
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Some are without well defined nucleus
(prokaryotic) and other are with well defined nucleus (eukaryotic).
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Mode of nutrition – Some are autotrophic and
other are heterotrophic.
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Planet earth is made up of abiotic and biotic
components.
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Biotic components are obviously the living
beings present around us.
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The question is
— Why
do we call them living? and
— How
do they differ from non-living?
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1.1 Basic principles of life :
A. Metabolism: -
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The living being once produced / born has to
survive.
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For survival, it needs energy and many chemical
molecules.
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For energy, it has to perform metabolism.
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Metabolism is breaking of molecules (catabolism)
and making of new molecules (anabolism).
— Catabolism
– e.g. Respiration
— Anabolism
– e.g. Photosynthesis
Questions:
— Name
the term used for breaking of molecules.
— Name
the term used for making of molecules.
— Name
the process which involves breaking of molecules.
— Name
the process which involves making of molecules.
B. Growth and Development
:-
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From birth onwards, organisms show tendency of
growth and development.
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This growth is a well-orchestrated process.
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You might have observed sand mounds, boulders
grow, etc.
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This growth is not from within and hence these
are not living beings.
Questions:
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Which process in the life of an organism is well
orchestrated?
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Name any two examples of non-living things
exhibiting growth.
C. Ageing : -
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Growth and development are not the processes which
have unlimited time span.
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At certain point of time, the molecules, organs,
systems begin to loose their effective working and become old.
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This is ageing process of the body.
Questions:
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Which life process do not have unlimited life
span?
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What is ageing?
D. Reproduction : -
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Life has to continue hence the organism tries to
produce a young one like itself.
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It is possible due to reproduction (asexual or
sexual).
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This ensures continuity of race.
— Mules,
sterile worker bees do not reproduce; yet are living.
— Can
we call reproduction as inclusive characteristic of life?
Questions:
— Define:
Reproduction.
— Name
the kinds of reproduction.
— Through
which process continuity of life is achieved?
— Which
life process ensures continuity of race?
— Which
living organisms are sterile?
E. Death :-
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As the body looses it's capacity to perform metabolism,
the organism dies.
F. Irritability :-
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Any living being responds to thermal, chemical
or biological changes in the surrounding.
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This is unique property of living beings.
Questions:
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Explain, how an organism dies?
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What is irritability?
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Which is the unique property of living
organisms?
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There is immense diversity in living organisms.
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Since time immemorial, variety of organisms are
living together on earth.
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In order to understand the interrelations
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between living and non-living as well as
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between two living beings or groups,
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Systematic study of these is essential.
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This data is also important for various
industries and agriculture.
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Intensive laboratory and field studies in order
to identify and classify the organisms form strong basis for meaningful use of
the collected data.
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If we need to study this diversity, certain aids
called taxonomical aids can be used.
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These includes herbaria, botanical gardens,
museums, biodiversity parks, etc.
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Can you tell?
1. How can we study large number
of organisms at a glance?
2. Whether all organisms prepare
their own food?
3. Which feature can be considered
as all inclusive characteristic of life? Why?
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Think about it
1. Can metabolic reactions
demonstrated in a test tube (called ‘in vitro’ tests) be called living?
2. Now a days patients are
declared ‘brain dead’ and are on life support. They do not show any sign of
self-consciousness. Are they living or non - living?
1.2 Herbarium :
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Que. What is herbarium?
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Herbaria
are effective tools in taxonomic studies.
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A
herbarium is essentially a dried plant specimen that is pressed, treated
and mounted on standard size sheet in order to preserve it.
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The
word herbarium (plural-herbaria) was coined by Pitton de Tournefort in
the book ‘Elemens’.
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Que. Who initiated herbarium?
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The
art of herbarium was initiated by an Italian taxonomist Luca Ghini
(1490-1556).
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Que. Enlist the things mentioned on herbarium sheet.
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Date,
place of collection along with detailed classification and highlighting with
its ecological peculiarities, characters of the plant are recorded on the same
sheet.
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Local
names and name of the collector may be added.
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Que. What is lable?
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This
information is given at lower right corner of sheet and is called 'label'.
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1.3 Botanical Gardens
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Que. What are botanical gardens?
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Botanical gardens are the places where plants of
different varieties collected from different parts of the world, are grown in a
scientific and systematic in a in vivo manner.
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Plants are labeled.
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The label-board shows scientific as well as
common name of the plant.
Conservation of Biodiversity :
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Biodiversity is the degree of variation
of life forms in an ecosystem.
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Biodiversity is essential to maintain
ecological stability.
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The extent of complexity and density of
biodiversity can be regarded as a measure of health of an ecosystem.
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Population explosion and over
exploitation of resources has resulted in loss of biodiversity at an
alarming rate.
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Conservation involves attempting to slow
down, stop or even reverse the loss in the natural habitat of
organism.
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This is known as in-situ conservation.
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Why does the loss of biodiversity matter?
– For
many people, it is a simple moral or ethical issue.
– We
share our planet with a huge range of other organisms and we have no right to
harm them.
– Biodiversity
helps to maintain stability in an ecosystem.
– Loss
of one variety of organisms can affect entire ecosystem.
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1.4 Museum
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Que. What are museums?
– Museums
are the places where, collections of preserved plant and animal specimens are
kept.
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Que. How animal specimens are preserved?
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Que. Which chemical is used to preserve
animals in museums?
– Plant
and animal specimens may be preserved in formalin (10% to 40% formaldehyde) in
transparent jars.
– Jars
are labelled.
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Que. How does larger animals and birds are
preserved?
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Que. What is taxidermy?
– Larger
animals like birds and mammals are usually stuffed and preserved.
– This
science is known as taxidermy.
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Specimens in dried form are also kept in
museum.
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We can even find systematic collections of
shells, skeletons of animals, insect boxes in museums.
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Thus, biological museums in educational
institutes are reference hubs of biodiversity studies.
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Que: Give reason: biological museums in
educational institutes are reference hubs of biodiversity studies.
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1.5 Zoological Parks
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Que. What are zoological parks?
– Zoological
Park generally known as zoo, is a place of interest for common man.
– In
a zoo, wild animals are kept in captivity.
– They
are protected and care is taken to provide conditions similar to their natural
habitat. (ex-situ)
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Que. How a zoo is important for a naturalist?
– In
a zoo, a naturalist can study food habits and behavior of animals.
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Flora, manuals, Monographs and Catalogue are
some other tools of maintaining biodiversity records.
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Que. What is flora?
– Flora
is the plant life occurring in a particular area on time.
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Que. What is a monograph?
– A
Monograph describes any one selected biological group.
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Que. What is the role of manual in
biodiversity?
– Manual
provides information, keys about identification of species found in a
particular area.
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Can you tell?
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1. What are the essentials of a good herbarium?
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2. Why should we visit botanical gardens,
museums and zoo?
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3. What is 'ex-situ' and 'in-situ'
conservation?
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1.6 Biodiversity parks :
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Que. What is biodiversity park?
– It
is an ecological assemblage of species that form self-sustaining communities on
degraded / barren landscape.
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e.g., Late Uttamrao Patil biodiversity park
Gureghar, Mahabaleshwar.
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This park is the best model for conservation of
natural heritage in urban landscape.
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Que. How can we understand the interrelation
between organisms?
– Systematic
classification of living organisms is helpful in understanding the
interrelations.
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Que. Why study of biodiversity is a must?
– In
order to understand interrelations between organisms and maintain harmony on
planet earth, study of biodiversity is a must.
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1.7 Key :
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Que. What is a key?
– Key
is taxonomical aid used for classification of plants and animals.
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Que. How a key is used in taxonomic
classification of plants and animals?
– The
keys are based on contrasting characters.
– One
of the contrasting characters gets accepted and other rejected.
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Que. What is a lead?
– The
statement in key is called a lead.
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Normally keys are analytical in nature.
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Internet my friend
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1. Collect information about botanical gardens,
zoological parks and biodiversity hot spots in India.
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2. Collect information of endemic flora and
fauna of India.
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Find out
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Human being is at key position in maintaining
biodiversity of earth. Find out more information about the following.
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1. Laws to protect and conserve biodiversity in
India.
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2. Environmental effects of ambitious projects
like connecting rivers or connecting cities by constructing roads.
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3. Did Bauxite mining in Western Ghats affect
critically endangered species like – Black panther, different Ceropegia spp., Eriocanlon spp.?
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Exercise
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1. Choose correct option
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A. Which is not a property of living being?
– a.
Metabolism
– b.
Decay
– c.
Growth
– d.
Reproduction
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B. A particular plant is strictly seasonal
plant. Which one of the following is best suited if it is to be studied in the
laboratory?
– a.
Herbarium
– b.
Museum
– c.
Botanical garden
– d.
Flower exhibition
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C. A group of students found two cockroaches in
the classroom. They had a debate whether they are alive or dead. Which life
property will help them to do so?
– a.
Metabolism
– b.
Growth
– c.
Irritability
– d.
Reproduction
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2. Distinguish between botanical gardens,
zoological park and biodiversity park with reference to characteristics.
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3. Answer the following questions
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A. Jijamata Udyan, the famous zoo in
Mumbai has acclimatised humbolt penguins.
Why should penguins be acclimatised when kept at a place away from their
natural habitat?
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B. Riya found peculiar plant on her visit
to Himachal Pradesh. What are the ways she can show it to her biology teacher
and get information about it?
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C. At Andaman, authorities do not allow
tourists to collect shells from beaches. Why it must be so?
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D. Why do we have green house in
botanical gardens?
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E. What do you understand from terms like
in situ and ex situ conservation?
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4. Write short notes
– A.
Role of human being in biodiversity conservation.
– B.
Importance of botanical garden.
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5. How can you, as an individual, prevent the
loss of Biodiversity?
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Practical / Project :
– 1.
Make herbarium under the guidance of your teacher.
– 2.
Find out information about any one sacred grove (devrai) in Maharashtra.
