The evidence for the origin of birds from reptiles is the presence in them of

The flippers of a seal are modified .......

Organs that have the same basic structure but perform different functions are known as .......

What are the hard parts of life forms found in rocks called?

Forelimbs of cat,lizard used in walking; forelimbs of whale used in swimming and forelimbs of bats used in flying are an example of

Homologous organs are ............. .