CLASS :11TH
SUB: BIOLOGY
UNIT: 1
CHAPTER:1
THE LIVING WORLD
In this chapter you will learn about:-
What is living world?
Why it is necessary to learn about living things?
How can we identify them?
How we name them?
How we categorized them?
What is living world?
Why it is necessary to learn about living things?
How can we identify them?
How we name them?
How we categorized them?
What is herbarium botanical garden and zoological park and why it is necessary?
In this chapter The Living World, we shall study about living organism. we know from early of our classes that living things can grow. Is it sufficient? let it be! lets start from from its diversity (difference) present in this world.when we see around, we notice, that land, water, mountains, coldest pole, deep ocean etc are habitat of different organism.
Isn't it interesting to know about all these creature,at least those who are helpful for human life. many of them make our even better.
Now coming to the point- What is living?
you may answer - living can grow. Is it correct? Nope! Because mountains, sand mounds and boulder do grow. Hence, it is necessary to know the correct definition of living.
GROWTH- It is of two types one is increase in numbers and another is increase in mass. In plants growth takes place through out their life while in animal it occurs only up to a certain period. But cell division occurs throughout their life to repair damaged cell.
In unicellular organism growth and reproduction are same, because when cell divides it forms a new individual, which may also called reproduction but in multi-cellular organism it is completely a different feature.
If we take growth as defining feature of living then, there is an objection i.e. some non living such as mountains, sand mounds, boulders do grow. whereas the growth of these non living are not due to cell division,it is due to accumulation of layers on the surface. Hence it is external factor while in living it is internal factor.
DUE TO ALL THESE REASON GROWTH CAN NOT BE TAKEN AS DEFINING FEATURE OF LIVING. IT IS ONLY A CHARACTER OF LIVING BECAUSE DEAD ORGANISM CAN NOT GROW.
In unicellular organism growth and reproduction are same, because when cell divides it forms a new individual, which may also called reproduction but in multi-cellular organism it is completely a different feature.
If we take growth as defining feature of living then, there is an objection i.e. some non living such as mountains, sand mounds, boulders do grow. whereas the growth of these non living are not due to cell division,it is due to accumulation of layers on the surface. Hence it is external factor while in living it is internal factor.
DUE TO ALL THESE REASON GROWTH CAN NOT BE TAKEN AS DEFINING FEATURE OF LIVING. IT IS ONLY A CHARACTER OF LIVING BECAUSE DEAD ORGANISM CAN NOT GROW.
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