Presence of gills in the tadpole of frog indicates that

1. fishes were amphibian in the past

2. fishes evolved from frog-like ancestors

3. frogs will have gills in future

4. frogs evolved from gilled ancestors

Which one of the following describes correctly the homologous structures?

The early-stage human embryo distinctly possesses

1. gills                             

2. gill slits

3. external ear (pinna)       

4. eyebrows                             

Potato and sweet potato 

Wings of pigeon, mosquito and bat show

1. divergent evolution 

2. atavism

3. convergent evolution 

4. all of these