Maharashtra Board Class 11 Biology Chapter 1 Living World PDF Download

1. Living World

Planet earth is made up of abiotic and biotic components. The biotic components are obviously the living beings present around us. The question is why do we call them living and how do they differ from non-living?

1.1 Basic Principles Of Life

A. The living being once produced / born has to survive. For survival, it needs energy and many chemical molecules. For energy, it has to perform metabolism. Metabolism is breaking of molecules (catabolism) and making of new molecules (anabolism).

B. From birth onwards, organisms show tendency of growth and development. This growth is a well-orchestrated process. You might have observed sand mounds, boulders grow, etc. This growth is not from within and hence these are not living beings.

C. Growth and development are not the processes which have unlimited time span. At certain point of time, the molecules, organs, systems begin to loose their effective working and become old. This is ageing process of the body.

D. Life has to continue hence the organism tries to produce a young one like itself. It is possible due to reproduction (asexual or sexual). This ensures continuity of race. Mules, sterile worker bees do not reproduce; yet are living. Can we call reproduction as inclusive characteristic of life?

E. As the body looses it's capacity to perform metabolism, the organism dies.

F. Any living being responds to thermal, chemical or biological changes in the surrounding. This is unique property of living beings.

Teacher's Note

Living things need food and water to stay alive. A plant needs water to grow, but a stone does not grow from inside like a plant does.

Exam Trick

Remember: All living things show metabolism - they break food for energy. Even if an animal sleeps or cannot move, if it eats and breathes, it is living.

Points to Remember

Living things need energy and food.
Living things grow from inside.
Living things can feel and respond to changes around them.
Living things can make babies.
Living things get old and then die.

There is immense diversity in living organisms. Since time immemorial, variety of organisms are living together on earth. In order to understand the interrelations between living and non-living as well as between two living beings or groups, systematic study of these is essential. This data is also important for various industries and agriculture. Intensive laboratory and field studies in order to identify and classify the organisms form strong basis for meaningful use of the collected data. If we need to study this diversity, certain aids called taxonomical aids can be used. These includes herbaria, botanical gardens, museums, biodiversity parks, etc.

1.2 Herbarium

The word herbarium (plural-herbaria) was coined by Pitton de Tournefort in the book 'Elemens'. The art of herbarium was initiated by an Italian taxonomist Luca Ghini (1490-1556). Herbaria are effective tools in taxonomic studies. A herbarium is essentially a dried plant specimen that is pressed, treated and mounted on standard size sheet in order to preserve it.

Date, place of collection along with detailed classification and highlighting with its ecological peculiarities, characters of the plant are recorded on the same sheet. Local names and name of the collector may be added. This information is given at lower right corner of sheet and is called 'label'.

Teacher's Note

A herbarium is like a dried flower kept in a book. Teachers keep these in school labs to show students different plant types.

Exam Trick

Remember: Herbarium = dried plant on paper. Think of it like pressing flowers between pages of a notebook. Schools use these to teach about plants.

Points to Remember

Herbarium is a dried and pressed plant on paper.
A label on the sheet tells where the plant was found.
Scientists use herbaria to study different plants.
The plant is treated and mounted carefully.
Herbaria help us learn about plant types.

1.3 Botanical Gardens

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. Plants are labeled. The label-board shows scientific as well as common name of the plant.

In 1543, first botanical garden of the world was established by an Italian Prof. Luca Ghini (A. D. 1490-1556) at Pisa, Italy. Botanical garden at Kew in England is known for largest collection of more than 30,000 specimens (preserved plants) and more than 7 million herbaria.

Teacher's Note

Botanical gardens are like big parks with many kinds of plants from around the world. In Mumbai, you can visit such gardens to see rare plants.

Exam Trick

Remember: Botanical garden = garden with live plants with labels showing their names. It is like a school for plants where we can see many types together.

Points to Remember

Botanical gardens grow many plant types from around the world.
Plants are labeled with their names.
They show both common and scientific names.
Plants are grown alive in the ground.
We can visit and study living plants here.

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