Correct Answer - Option 2 : Tiger
Concept:
Some characteristic features of mammals are:
- They have body hair
- Ears are external
- They are warm-blooded( internal body temperature is maintained)
- Female mammals have well developed mammary glands to feed their young ones
Explanation:
Ears:
- Different animals have different kinds of ears, ears help us to hear.
- Some animals have external ears, like elephants, tigers, foxes etc.
- Some animals do not have ears, like fishes, lizards, frogs and birds.
- In some animals, you can see the ears, in some you can not.
- We can not see a bird’s ears.
- A bird has tiny holes on both sides of its head.
- Generally, the holes are covered with feathers.
- They help the bird to hear.
- If you look carefully, you will see tiny holes on a lizard’s head. These are its ears.
- A crocodile also has ears like this, but we can not see them easily.
Thus, in the list, tiger is different, as it has external ears and others don't have external ears.