Question

Write the distinguishing features of class Reptilia.

Answer 1

They lay their eggs on land. They typically reproduce sexually with interior fertilization. A few species types are ovoviviparous, with the eggs staying in the mother's body until they are prepared to hatch. Different species are viviparous, with the posterity brought into the world alive.

Complete answer
Reptiles are the vertebrates that are covered in a special skin that is made up of scales and bony plates with the combination of both and includes certain tortoises, snakes, lizards, crocodiles. They undergo molting whether they shed their skin which is the outer layer of the body. Reptiles duplicate explicitly through inside fertilization; a few animal types are ovoviviparous (lay eggs) and others are viviparous (live birth).
Reptiles are ectotherms: they rely upon their general climate to control their internal heat level; this prompts preferences, for example, not being reliant on metabolic energy from nourishment for body heat. They are additionally poikilotherms: an organism whose internal heat levels shift instead of stay stable. Some reptiles go into brumation: an extensive period during a cold climate that comprises no eating and diminished digestion.

Additional information
Reptiles are ectotherms: An organism whose primary wellspring of body heat originates from the climate. This is as opposed to endotherms, which utilize the warmth delivered by digestion to control the internal heat level. Notwithstanding being ectothermic, reptiles are arranged as poikilotherms: creatures whose internal heat levels fluctuate as opposed to staying stable. Reptiles have conducted transformations to help control internal heat levels, for example, basking in sunny places to warm up and finding shady spots or going underground to cool down. The benefit of ectothermy is that metabolic energy from food isn't needed to warm the body; accordingly, reptiles can make due on around $10\%$ of the calories required by a similarly-sized endotherm.

Note:
There is one key adaptation that has allowed reptiles to live on land was the improvement of their scaly skin which contains the protein keratin and waxy lipids, diminishing water moisture from the skin. Because of this occlusive skin, reptiles can't utilize their skin for breath, as do amphibians; all breath with lungs.