Name: Foetus Development
Uploaded: 2019-07-19
Duration: 9 min 51 s
Description: A baby goes through several stages of development, beginning as a fertilised egg. The egg develops into a blastocyst, an embryo, and then a foetus.

Question

Give the general characteristics of the vertebrates and list the distinguishing features of the classes under it.

Accepted Answer

Main characteristics of Vertebrates are given below:
1) Notochord, forms on the dorsal side of the primitive gut in the early embryo and is present at some developmental stage in all chordates.
2) At some stage of their life, they possess a hollow dorsal nerve cord.
3) Possess at some stage of their life gill slits in the pharyngeal region.
4) A tail is present in the post-anal part of the body which is reduced or absent in many adults.
5) A well-developed brain is present inside a box called as cranium.

Classification of Vertebrates:
Based on their anatomical and physiological features, Vertebrates are classified into seven classes. These are as follows:

Mammals (Class Mammalia): These organisms can regulate their body temperature. Mammals have mammary glands that produce milk to nourish their young ones.

Birds (Class Aves): These are characterised by feathers, toothless beaks and a high metabolic rate. Members of class Aves lay hard-shelled eggs.

Reptiles (Class Reptilia): The characteristic feature of reptiles is that they are ectothermic in nature. Their skin is dry, rough and without glands bearing scales. Their body is divided into head, neck, trunk, and tail.

Amphibians (Class Amphibia): The distinguishing feature that separates amphibians from reptiles is their breeding behaviour. Most amphibians need a body of water to breed as their eggs are shell-less. Furthermore, they undergo metamorphosis where the young ones transform from fully-aquatic larval form (with gills and fins) to terrestrial adult form.

Bony fishes (Class Osteichthyes): This class of fishes is characterised by their skeleton which is composed primarily of bone rather than cartilage.

Cartilaginous fishes (Class Chondrichthyes): As the name suggests this class of fishes is characterised by their skeleton composed of cartilage.

Jawless fishes (Class Agnatha): Agnatha have a jawless, circular mouth with rows of small sharp teeth which aid in holding and feeding on other fishes. Most members of this class are parasites and scavengers.

Give the general characteristics of the vertebrates and list the distinguishing features of the classes under it.

Important Questions on Animal Kingdom

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