Q.Which one of the following is a non-poisonous snake?

From Fish to Birds to Humans — The Big Picture

Think of vertebrates as animals with a backbone. That's the club you belong to — humans, dogs, frogs, fish, snakes, birds. But inside that club, there's an enormous range of body plans. Some have scales, some have feathers. Some live only in water, some on land. Some lay eggs, some give birth to live young.

The classification of vertebrates is simply a way of grouping them by shared structural features — things you can see and feel, like skin covering, heart chambers, or how they breathe. It's not random. Each group represents a major evolutionary step in how animals solved the problems of living on Earth.

The Seven Classes — What Makes Each One Distinct

1. Cyclostomata — The Jawless Vertebrates

These are the most primitive living vertebrates. They look like eels but have a round, sucker-like mouth with no jaws. Their skeleton is made of cartilage (not bone), and they have no paired fins.

Examples: Lamprey, Hagfish.

2. Chondrichthyes — The Cartilaginous Fish

Sharks, rays, and skates. Their skeleton is entirely cartilage — the same flexible stuff in your ears and nose. They have jaws and paired fins, and their skin is covered with tiny, tooth-like scales called placoid scales.

Examples: Shark, Stingray.

3. Osteichthyes — The Bony Fish

This is the largest group of vertebrates. Their skeleton is made of bone. They have a swim bladder (a gas-filled sac that controls buoyancy) and an operculum (a bony flap covering the gills). Their scales are flat, overlapping plates called cycloid or ctenoid scales.

Examples: Rohu, Salmon, Goldfish.

4. Amphibia — The Double-Life Vertebrates

Amphibians live part of their life in water and part on land. Their skin is moist and glandular (no scales). They lay eggs without a shell in water, and the young (tadpoles) breathe through gills. Adults develop lungs and can breathe air.

Examples: Frog, Salamander, Toad.

5. Reptilia — The First True Land Vertebrates

Reptiles were the first vertebrates to fully break free from water. Their skin is dry, thick, and covered with scales (made of keratin). They lay shelled eggs on land — the amniotic egg that protects the embryo from drying out. They breathe only through lungs.

Examples: Lizard, Snake, Turtle, Crocodile.

6. Aves — The Feathered Vertebrates

Birds are the only animals with feathers. Their forelimbs are modified into wings (even flightless birds like ostriches have wings). They have a beak with no teeth, and their bones are hollow (pneumatic) to reduce weight for flight. They lay hard-shelled eggs and are warm-blooded (endothermic).

Examples: Pigeon, Eagle, Sparrow.

7. Mammalia — The Milk-Giving Vertebrates

You are here. Mammals have mammary glands that produce milk to feed their young. Their skin has hair (at least at some stage). They are warm-blooded, have a 4-chambered heart, and most give birth to live young (except monotremes like the platypus, which lay eggs).