Question

Fertilised eggs covered by calcareous shells are found in

• A. Amphibians, reptiles and birds
  
• B. Fishes and amphibians
• C. Reptiles, birds and mammals
  
• D. Reptiles and birds

Answer 1

The correct option is D Reptiles and birds

Introduction to oviparous animals
In oviparous animals, the females lay either fertilised or unfertilised eggs (fertilised externally). Thus, the development of the zygote happens outside the body of the mother. The fertilised eggs that are released by birds and reptiles have a calcareous scale.Unfertilised eggs released by fishes and amphibians do not have a calcareous shell.

Viviparous animals
Viviparous animals are those in which the zygote develops within the mother’s body and the females directly give birth to young ones. For example, mammals.

Final answer
(d) Reptiles and birds