state one characteristic which shows that birds are closely related to reptiles. (2 marks)
Some characteristics shared by reptiles and birds, which show their close relation are:
- Birds and reptiles share several skeletal and internal characteristics. Both have five fused bones in their jaws, a single middle ear bone and an almost identical nucleated red blood cell structure.
- Reptiles and birds have a cloaca that serves as their body's only means of waste, reproductive and intestinal tract evacuations.
- The bodies of birds and reptiles are covered entirely with different versions of scales that have developed over hundreds of thousands of years
- Birds and reptiles are oviparous, i,e egg laying and the structure of the amniotic shelled eggs reptiles and birds lay are quite similar.
- There is also evidence that suggests reptiles often show the same care and attention a mother hen will provide her young chicks, and birds and reptiles also protect their nests with a great vigor.