[Biology Class Notes] on Vertebrates Pdf for Exam

Animals that have skeletons and backbones are called vertebrates. There are different kinds of vertebrates that fall under various classes. These include humans, mammals, birds, amphibians, reptiles, and fish. 

Before we proceed to vertebrate characteristics, note that Vertebrata falls under phylum Chordata. Other sub-phyla are – Cephalochordata and Urochordata. 

Characteristics of Vertebrates 

Thinking what are the basic features of vertebrates? Read below to know more about it.

• There is a distinct similarity in the anatomy of vertebrates with the presence of a vertebral column, gastrointestinal tract, and spinal cord.

• Notochord develops into a vertebral column, and the vertebrae are present on the dorsal side.

• Presence of the central nervous system is a crucial identifier. Nerve tube of the spinal cord in the anterior part expands into the brain. 

• Jaws are present in some vertebrates. Order of vertebrates includes jawless species.

• Internal skeleton aids in the distribution of different muscle attachment nodes.

Fun Fact!

Even though different types of vertebrates across the world include approximately 65,000 species, it does not amount to more than 3% of animals on the face of Earth. Hence most animal species in our world are actually invertebrates!

What is the Classification of Vertebrates?

Find out more about the classification of vertebrates with examples. 

Class – Mammalia 

Mammals have a four-chambered heart and warm blood. Usually, they give birth to their offspring, but exceptions like Echidna can also be found, which reproduce by laying eggs. The habitation of such vertebrates is varied.

Mammary glands are present for feeding the younger ones. Mammals have functional limbs and external pinna. Fertilization in these vertebrates is usually internal. Examples – kangaroo, dolphin, whale, platypus.

Class – Aves

Birds fall under this class of vertebra. The distinctive feature of Aves is the feather-covered body and forelimbs that evolved as wings for flight. An exception in this regard is Ostrich, which cannot fly.

Bones have air cavities, and additional chambers can be found in the digestive tract. Example – vulture, pigeon, crow, etc.

Class – Reptilia

The body of reptiles is covered by scutes or scales, and in some instances, the epidermal scales can be cast-off as well. There is no external pinna and the tympanum performs the auditory functions. Reptiles have three-chambered hearts, except crocodiles, which it is four-chambered. As opposed to other vertebrates, reptiles are cold-blooded animals. Examples – tortoise, turtle, crocodile, snake, etc. 

Class – Amphibia

Amphibians are both terrestrial and aquatic animals. The tympanum acts as the ear, and the body is covered by moist skin without scales. Cloaca acts as a common opening to the reproductive tract, urinary tract, and alimentary canal. Respiration is through both lungs and gills, and the heart is three-chambered. Examples – salamander, tree-frog, toad, etc.

Class – Pisces

This class includes fish with scales all over the body. These vertebrates are oviparous, and respiration takes place only through gills. Fish have two-chambered hearts, and the skeleton is made entirely of cartilage. Exception being sharks with a skeleton made up of both cartilage and bone.  

Test Your Knowledge 

1. Vertebrates are of five kinds. Which of the following does not fall under vertebrate?

1. Birds 

2. Mammals 

3. Reptiles 

4. Arthropods

Ans. (d) Arthropods

2. Which of the following vertebrates is not considered as a mammal, even though other characteristics of vertebrates are present?

1. Sloth 

2. Armadillo

3. Whale 

4. Shark 

Ans. (d) Shark

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Vertebrates are those organisms that have skeletons, a bone structure, and a backbone. There are various types of vertebrates and they fall under various classes, some vertebrates are humans, birds, amphibians, mammals, fish, and reptiles. Vertebrata comes under the phylum Chordata. Other subcategories are – Cephalochordata and Urochordata.

The concept of vertebrates is taught in schools much earlier, however, the properties and characteristics of vertebrates are studied in depth in class 11 biology. Vertebrates are mainly discussed in the NCERT book in chapter 4 animal kingdom, chapter 21 control, and coordination, chapter seven structural organization in animals. These chapters are prescribed by the Central Board of secondary education and are taught in schools that follow the curriculum set by the CBSE. Properties and characteristics of vertebrates are extremely important in the sense that it carries significant weightage in the examinations. Students who are aspiring to go into the medical field will have to give NEET which is the national eligibility cum entrance test. The basis for NEET is the study of biology physics and chemistry of classes 11 and 12 and therefore students should first clear their bases which are taught in class 11 NCERT books.

Key Concepts That are Important to Study in Relation to Vertebrates-

4.2 CLASSIFICATION OF ANIMALS

• 4.2.1 Phylum – Porifera

• 4.2.2 Phylum – Coelenterata (Cnidaria

• 4.2.3 Phylum – Ctenophora

• 4.2.4 Phylum – Platyhelminthes

• 4.2.5 Phylum – Aschelminthes

• 4.2.6 Phylum – Annelida

• 4.2.7 Phylum – Arthropoda

• 4.2.8 Phylum – Mollusca

• 4.2.9 Phylum – Echinodermata

• 4.2.10 Phylum – Hemichordata

• 4.2.11 Phylum – Chordata

• 4.2.11.1 Class – Cyclostomata

• 4.2.11.2 Class – Chondrichthyes

• 4.2.11.3 Class – Osteichthyes

• 4.2.11.4 Class – Amphibia

• 4.2.11.5 Class – Reptilia

• 4.2.11.6 Class – Aves

• 4.2.11.7 Class – Mammalia