Choradata

Chordates are animal possess notochord ,dorsal hollow nerve cord and pharyngeal gill slits at any stage of life. They show following features-

• They have vertebral column and internal skeleton.

• They have bilateral symmetry and are triploblastic.

• They have coelomic cavity.

• Their body is differentiated into tissues and organs.

• Their body consists   head, neck, trunk  and tail.

• They have two pairs of fins or limbs.

• The respiration in aquatic forms is by gills and in land  forms respiration is by lungs.

  

features of Chordates

Chordates are classified in  "Pisces  ,Amphibians ,Reptilia ,Aves & Mammal.

                                                              

                                                              Pisces

These are the aquatic chordates

•         These are known as fishes .

•         Their skin is covered with scales or plates

•         They respire by gills.

•         They have streamlined body and fins which help them to move in water.

•         They are cold blooded and their heart has only two chambers.

•         They lay eggs from which the young ones hatch out.

•          Cartilaginous fish  have skeleton made of cartilage like Sharks, Rays etc.

•          Bony fish have skeleton made of bones and cartilage like Tuna, Rohu etc.

                                                                 Amphibians 

Amphibians can live in water an on land.

•         They are found in land and water.

•          They do not have scales but have mucous glands on their skin.

•          They are cold blooded and the heart is three chambered.

•          Respiration is through gills or lungs.

•          They lay eggs in water.

•             Eg :- Frogs, Toads, Salamanders etc.

Morphology Of Frog

                                            

                                                    Reptilia 

These are creeping chordates .

•         They have scales and breathe through lungs.

•         They are cold blooded.

•         Most of them have three chambered heart but crocodiles have four chambered heart.

•         They lay eggs with hard covering in water.

•            Eg :- Snakes, Turtles, Lizards, Crocodiles etc.

Examples of Reptiles

                                                

                                            Aves  (Birds)

 These are flying chordates -

• They are warm blooded animals.

• They have four chambered heart. 

• They breathe through lungs.

• They have a beak.

• They have an outer covering of feathers. 

• Their two fore limbs are modified into wings for flying. 

• They lay eggs.

   Eg :- Crow, sparrow, Pigeon, Duck, Stork, Ostrich etc. 

features in a Bird

                                                               Mammals

•         They are warm blooded animals.

•         The skin has hairs and sweat glands.

•         They have four chambered heart.

•         They have mammary glands for production of milk to nourish their young ones.

•         Most of them give birth to their young ones. Some of them lay eggs (like Platypus and Echidna).

           Eg :- Cat, Rat, Dog, Lion, Tiger, Whale, Bat, Humans etc.

A particular feature of a mammal

Examples of Mammals