Question

the common thing in fish, amphibians and reptiles

Answer 1

the common thing is that they both lay eggs.

Answer 2

amphibians
to identify an animal as amphibians it should have each of these characters :
I) Amphibians have a backbone. they are vertebrates.
2)amphibians are cold blooded. they cannot regulate their own body temperature.
3)amphibians spend at least part of their life in water and on land.
4)amphibians do not have scales on their body and is permeable (molecules and gases can pass through ).
5)most amphibians go through metamorphosis
6)they lay eggs
reptiles
to identify an animal as reptiles it should have each of these characters
1)they have a backbone. they are vertebrates
2)they are covered in scales.
3)most reptiles lay eggs.
4)some reptiles like the bow constrictor give birth to their young ones.
5)almost all reptiles are cold blooded.
6)they lay eggs
fish
to identify an animal as fish it. should have each of these characters
1)they live in water
2)they breathe through their gills
3)they absorb oxygen through their gills
4)they are vertebrates
5)almost all fish are cold blooded
6)they lay eggs
the common thing in all are they lay eggs