Explain how animals in Vertebrata are classified into further subgroups.

Animals belonging to vertebrates are classified into five classes:

Class Pisces

1. This class includes fish.
2. They are oviparous.
3. Respiration occurs through the gills.
4. The heart is two-chambered.
5. The entire skeleton is made up of cartilage.
6. Example- Fishes

Class Reptilia

1. Their bodies are covered with hard scales.
2. The heart is three-chambered, except for the crocodile.
3. They are cold-blooded.
4. Example- Tortoise, snake

Class Amphibia

1. They live on both land and water.
2. They have most skin without scales.
3. Respiration occurs through the gills and lungs.
4. Example- Frog, toad

Class Aves

1. This class includes birds.
2. The body is covered with feathers.
3. They are oviparous.
4. Bones are hollow and have air cavities.
5. Example- Pigeon, crow

Class Mammalia

1. This class includes organisms having four-chambered
2. They are usually viviparous and warm-blooded.
3. Have mammary glands.
4. Example- Human beings, dolphins.