The Living World PPT Biology Class 11

 Page 1


THE LIVING WORLD
CLASS XI
Page 2


THE LIVING WORLD
CLASS XI
THE LIVING WORLD
? Life is a unique, complex organization of molecules,
expressing through chemical reactions which lead to
growth, development, responsiveness, adaptation &
reproduction.
? Life is a biochemical process.
Page 3


THE LIVING WORLD
CLASS XI
THE LIVING WORLD
? Life is a unique, complex organization of molecules,
expressing through chemical reactions which lead to
growth, development, responsiveness, adaptation &
reproduction.
? Life is a biochemical process.
Characteristics  of living organisms
Growth
? It is the increase in mass and number of cells.
? In plants, growth by cell division occurs continuously
throughout their life span.
? In animals, growth is only up to a certain age.
? Non-living objects grow by accumulation of material
on the surface. In living organisms, growth is from
inside.
Page 4


THE LIVING WORLD
CLASS XI
THE LIVING WORLD
? Life is a unique, complex organization of molecules,
expressing through chemical reactions which lead to
growth, development, responsiveness, adaptation &
reproduction.
? Life is a biochemical process.
Characteristics  of living organisms
Growth
? It is the increase in mass and number of cells.
? In plants, growth by cell division occurs continuously
throughout their life span.
? In animals, growth is only up to a certain age.
? Non-living objects grow by accumulation of material
on the surface. In living organisms, growth is from
inside.
Shape and size
? Living beings have a definite shape and size, which get
modified to some extent when growth occurs.
? Living beings have been called as morphous (with
definite shape) and non living objects are called as
amorphous (no definite shape)
Page 5


THE LIVING WORLD
CLASS XI
THE LIVING WORLD
? Life is a unique, complex organization of molecules,
expressing through chemical reactions which lead to
growth, development, responsiveness, adaptation &
reproduction.
? Life is a biochemical process.
Characteristics  of living organisms
Growth
? It is the increase in mass and number of cells.
? In plants, growth by cell division occurs continuously
throughout their life span.
? In animals, growth is only up to a certain age.
? Non-living objects grow by accumulation of material
on the surface. In living organisms, growth is from
inside.
Shape and size
? Living beings have a definite shape and size, which get
modified to some extent when growth occurs.
? Living beings have been called as morphous (with
definite shape) and non living objects are called as
amorphous (no definite shape)
Reproduction
? It is the production of progeny similar to those of
parents.
? Organisms reproduce asexually and sexually.
? Growth is the increase in cell number or mass. Hence
in unicellular organisms, growth & reproduction are
same.
? Many organisms do not reproduce (e.g. mules, worker
bees, infertile human couples, etc). Hence,
reproduction is not a perfect defining characteristic of
living organisms