Table of Contents
- Systems in Amphibia
- Systems in Reptiles
- Did You Know?
- What’s Next?
In the previous segment of the chapter ‘Diversity in Living Organisms’, we studied about Agnatha and Pieces. In this segment, let us get introduced to Amphibia and Reptilia.
What are Amphibians?
Life cycle of Frog
- The organisms which show a unique ability to live on land as well as in water are called
amphibians and the subphylum is called Amphibia. For example, frog, salamander, etc.
- Frogs lay their eggs in water. The eggs develop into tadpoles. They swim and live in the surrounding water.
- Once they grow into adult frogs, they come out of the water and start living in terrestrial habitats.
- Some part of their life is mandatorily spent in the water while some on land.
What are the different systems in amphibians?
Respiratory system of Amphibians
- Frogs and other amphibians have a specialised respiratory system. On land, they breathe with their lungs, but in water, they carry out gaseous exchange through their skin. Their skin is usually soft, scale-less and moist.
- The digestive system begins at the mouth and ends at the anus.
- The excretory system has a pair of kidneys and the complete urinary system.
- The nervous system of amphibians has a small brain located in the head region, a spinal cord, and nerves running all over the body which carry messages.
- In amphibians, the sexes are separate. Females are sometimes larger in size compared to males.
Internal systems of Amphibians
- Fertilisation is usually external.
In frogs, the eggs are released in the water by the female and get fertilised by the floating sperms. The fertilisation results in the formation of small embryos which stick together to form a mass with jelly-like covering. The tadpoles on development get released in water and survive as herbivores. After this stage, Metamorphosis occurs and the tadpole changes into an adult frog.
What are Reptiles?