Identifying Which Animal Does Not Belong to the Mammal Family

The question asks us to identify which of the listed animals is not a mammal. To answer this, we need to understand the characteristics of mammals and other animal classes.

What are Mammals?

Mammals are a class of vertebrates characterized by:

• Being warm-blooded (homeothermic).
• Having hair or fur at some point in their lives.
• Producing milk to feed their young through mammary glands.
• Giving birth to live young (though a few, like the platypus, lay eggs).
• Having a four-chambered heart.

Considering the Options

Let's look at each option provided:

• Dog: Dogs have fur, are warm-blooded, give birth to live young, and nurse their puppies with milk. Dogs are mammals.
• Whales: Although they live in water, whales are warm-blooded, breathe air with lungs, give birth to live young, and nurse their calves with milk. Whales are mammals.
• Bats: Bats are the only mammals capable of true flight. They have fur, are warm-blooded, give birth to live young, and nurse their pups. Bats are mammals.
• Frog: Frogs are cold-blooded (poikilothermic). They typically lay eggs in water, which hatch into larvae (tadpoles) that live in water and breathe with gills. Tadpoles undergo metamorphosis to become adult frogs, which breathe with lungs and through their moist skin. Frogs do not have fur or hair and do not produce milk. Frogs belong to the class Amphibia.

Classifying the Animals

Conclusion

Based on the characteristics of mammals and amphibians, the Frog is the only animal in the list that does not belong to the mammal family (class Mammalia). Frogs belong to the class Amphibia.