class 12 bilogy chapter presentation by YUSUF BADAT

1. A BRIEF ACCOUNT OF
EVOLUTION
By yusuf badat

2. EVOLUTION OF PLANTS
 About 2000million years ago the first cellular forms of life appeared
on the earth. Some of these cells had the ability to release oxygen.
 Slowly single-cell organisms became multi-cellular life forms.
 The evolution of plants has resulted in widely varying levels of
complexity, from the earliest algal mats , through bryophytes , lycopods,
and ferns , to the complex gymnosperms and angiosperms of today.

4. EVOLUTION IN ANIMALS
 By the 500mya , invertebrates were formed and active.
 Jawless fish probably evolved around 350mya.
 Sea weeds and few plants existed probably around 320mya.
 In 1938, a fish called lobefins was firstly founded in south- Africa,
which is thought to be extinct. This fish could live on both land and
water . Now no specimens of this is left with us . This was ancestors
of modern day frog and salamanders.

6. ORIGIN AND EVOLUTION
OF MAN