Question

Explain how animal in vertebrates are classified into further sub - group

Answer 1

Vertebrates are further classified according to several criteria like exoskeleton, respiratory organs, method of giving birth, number of chambers in heart, mode of living etc.

They are further classified into classes Pisces, Amphibia, Reptilia, Aves and Mammals.

Pisces

include the fishes. They are aquatic, cold-blooded animals having 2 chambers of heart. Their skin is covered with scales/plates. They lay eggs and respire through gills. They excrete urea. Endoskeleton may be bony or cartilagenous.

Amphibians

on the other hand live partly in water and partly on land. Their skin is smooth without scales. Respiration is through gills, lungs, skin or buccal lining. They possess 3 chambered heart and are oviparous. They are cold-blooded.

Reptiles

are the creeping vertebrates possessing dry scaly exoskeleton. They are cold-blooded, breathe through lungs and possess 3 chambered heart. They are oviparous and excrete uric acid.

Aves

include the birds. They are warm-blooded, oviparous vertebrates with a covering of feathers. Their fore-limbs are modified into wings for flight. Respiration is through lungs and 4 chambered heart is present.

Mammals

possess mammary glands for feeding the young. They are warm-blooded with 4 chambered heart. They are viviparous. They possess external pinna and hair on skin. Parental care is highly developed. They excrete urea.

Answer 2

$\huge\mathfrak\color{blue}{Answer}$

Animals in Vertebrata are classified into five classes:

• Class Pisces: This class includes fish such as Scoliodon, tuna, rohu, shark, etc. These animals mostly live in water. Hence, they have special adaptive features such as a streamlined body, presence of a tail for movement, gills, etc. to live in water.

• Class Amphibia: It includes frogs, toads, and salamanders. These animals have a dual mode of life. In the larval stage, the respiratory organs are gills, but in the adult stage, respiration occurs through the lungs or skin. They lay eggs in water.

• Class Reptilia: It includes reptiles such as lizards, snakes, turtles, etc. They usually creep or crawl on land. The body of a reptile is covered with dry and cornified skin to prevent water loss. They lay eggs on land.

• Class Aves: It includes all birds such as sparrow, pigeon, crow, etc. Most of them have feathers. Their forelimbs are modified into wings for flight, while hind limbs are modified for walking and clasping. They lay eggs.

• Class Mammalia: It includes a variety of animals which have milk producing glands to nourish their young ones. Some lay eggs and some give birth to young ones. Their skin has hair as well as sweat glands to regulate their body temperature.