find the odd-one out.Give reasons

1. Tape worm, round worm , liver fluke, earthworm
2. starfish , brittle star, sea urchin , crab
3. monkey, cow, humans, crocodile.
4. Crocodile,tortoise, frog,snake

1. Earthworm is the odd one here as all other organisms like tape worm, round worm and liver fluke are parasites but earthworm is free living.

2. Crab has ten feet whereas starfish, sea urchin and brittle star have five feet.

3. Crocodile is the odd one as it is a reptile and all other animals are mammals.

4. Frog is an amphibian and crocodile, tortoise or snake is reptiles.