Biology · Evolution · NEET
NCERT says fish with stout and strong fins could move on land and go back to water, about 350 mya. These stout-finned fish gave rise to the first amphibians that lived on both land and water. No fossil specimens of these first amphibians are left with us, but they were the ancestors of modern-day frogs and salamanders. So the sequence is: strong-finned fish to first amphibians to modern frogs/salamanders.
This is a common NEET point. Amphibians evolved into reptiles, and reptiles lay thick-shelled eggs which do not dry up in the sun, unlike the eggs of amphibians. The thick shell protects the developing embryo from drying, which let reptiles live fully on land. Amphibian eggs lack this protection, so amphibians still depend on water for reproduction.
The Coelacanth is a FISH, not an amphibian. In 1938 a fish caught in South Africa turned out to be a Coelacanth — a lobe-finned fish once thought extinct. It is linked to this topic because it belongs to the group of stout, strong-finned fishes that shows how fish fins could support the body, the same feature that helped fish move onto land toward amphibian ancestry.
Yes. NCERT notes that some land reptiles went back into water and evolved into fish-like reptiles, probably around 200 mya — for example, Ichthyosaurs. This is a good example of reversal: land reptiles becoming water-adapted. Do not confuse Ichthyosaurs (reptiles that returned to water) with true fishes.
Amphibians came first, then reptiles. The order is: jawless fish (about 350 mya) to stout-finned fish that moved onto land to first amphibians to reptiles. Reptiles are more advanced because their thick-shelled eggs freed them from water for reproduction. After reptiles, in the next 200 million years, reptiles of different shapes and sizes (including dinosaurs) dominated the earth.
Match List I with List II with respect to chronology of evolution of life forms. List-I: A. About 65 mya B. About 500 mya C. About 350 mya D. About 320 mya List-II: (I) Jawless fish probably evolved (II) The dinosaurs suddenly disappeared from the earth (III) Seaweeds and few plants probably existed (IV) Invertebrates were formed and became active
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Jawless fish probably evolved around 350 mya. Around the same time (about 350 mya), fish with stout and strong fins could move on land and go back to water, leading toward the first amphibians.
Jawless fish to stout-finned fish (moved onto land, about 350 mya) to first amphibians (ancestors of frogs and salamanders) to reptiles (with thick-shelled eggs). This land-based egg let reptiles fully leave water.
Reptiles lay thick-shelled eggs that do not dry up in the sun, unlike amphibian eggs. The shell protects the embryo from drying, so reptiles could reproduce on land without needing water, a major evolutionary advantage.
No. Ichthyosaurs are fish-like REPTILES. NCERT says some land reptiles went back into water and evolved into fish-like reptiles, probably around 200 mya, for example Ichthyosaurs.
NEET often asks the chronological order and simple facts from the brief account of evolution — like when jawless fish evolved, the fish-to-amphibian-to-reptile order, and the thick-shelled egg point. These are direct one-mark NCERT-line questions, as seen in NEET 2026.
