Concept: All the given animals—snake, turtle, frog, and crocodile—reproduce by laying eggs; this is their common trait despite belonging to different classes.
Explanation: Snakes, turtles, and crocodiles are reptiles; frogs are amphibians.
Reptiles have dry, scaly skin and a three‑chambered heart (except crocodiles, which have four chambers).
Frogs have moist skin, breathe through gills as larvae, and can live both on land and in water.
The only feature shared by all is that they lay eggs (oviparous).
Reptiles lay eggs on land; frogs lay eggs in water.
Additional InformationCharacteristics of Reptilia
Following are the important characteristics of the animals belonging to Class Reptilia:
These are creeping and burrowing terrestrial animals with scales on their body.
They are cold-blooded animals found in most of the warmer regions of the world.
Their skin is dry, and rough, without any glands.
The body is divided into head, neck, trunk, and tail.
Few of these shed the scales on their skin as skin cast.
The respiration takes place with the help of the lungs.
The skull is Monocondylic.
They have two pairs of pentadactyl limbs, each bearing claws. Snakes are an exception.
The heart is 3 chambered. However, crocodiles have a 4-chambered heart.
The nervous system comprises 12 pairs of cranial nerves.
The lateral line system is absent in reptiles.
Except for snakes, all the reptiles have well-developed ears.
They possess a typical cloaca.
Answer: B. They lay eggs
