Comment upon the habitats and external f | Class 11 Biology Chapter Animal Kingdom, Animal Kingdom NCERT Solutions

Class- Amphibia

Habitat- Amphibians can live on both land and water.

External features:

1. They have very smooth skin (without scales), moist and are thin.
2. The eyes have eyelids. Ear is represented by tympanum.
3. They have pair of limbs. Body is divisible in head and trunk. Tail may be present in same. Example: Toad, Frog etc.
4. Respiration occurs by gills, lungs.
5. Contains 10 pairs of cranial nerves.

Class- Reptilia

Habitat- The class name refers to their creeping crawling mode of locomotion. They are mostly terrestrial (lives on land).

External features:

1. They are covered with dry and cornified skin and scales.
2. They do not have external ear opening. Ear is represented by tympanum.
3. They have pair of limbs. Example: Crocodile, Turtle etc.
4. Respiration occurs by lungs.
5. They have four chambered heart.
6. Excretory system contains kidneys.
7. Contains internal fertilization.