Careers360 Logo
NCERT Solutions for Class 11 Biology Chapter 4 - Animal Kingdom

NCERT Solutions for Class 11 Biology Chapter 4 - Animal Kingdom

Edited By Irshad Anwar | Updated on May 14, 2025 10:24 AM IST

NCERT Solutions for Class 11 Biology Chapter 4 help students in understanding the diversity of animals. They describe how the animals are classified based on features such as body structure, cell organisation, symmetry, and body cavity presence. NCERT Solutions for Class 11 offer straight explanations to simplify learning about animal classification.

This Story also Contains
  1. NCERT Solutions For Class 11 Biology: Animal Kingdom PDF Download
  2. Access the NCERT Solutions for Class 11 Biology Chapter 4 Animal Kingdom Solved Exercise
  3. Important Question of Class 11 Animal Kingdom
  4. Approach to Solve Questions of Class 11 Chapter 4
  5. What Extra Should Students Study Beyond the NCERT for NEET?
  6. Chapter Wise NCERT Solutions for Class 11 Biology
NCERT Solutions for Class 11 Biology Chapter 4 - Animal Kingdom
NCERT Solutions for Class 11 Biology Chapter 4 - Animal Kingdom

The NCERT Solutions give clear, step-by-step answers to all questions of the chapter according to the latest CBSE syllabus. They include important points such as classification, animal phyla, and characteristic features like segmentation and notochord. Complex terms are explained in simple words so that students can learn easily. The solutions are easy to download and assist students in preparing well for the board and competitive exams.

Background wave

NCERT Solutions For Class 11 Biology: Animal Kingdom PDF Download

Given below is the PDF of the detailed question and answer of this chapter:

Download PDF

Also Read,

Access the NCERT Solutions for Class 11 Biology Chapter 4 Animal Kingdom Solved Exercise

Given below are the exercise questions with detailed explanations for better understanding.

Q1. What are the difficulties that you would face in the classification of animals if common fundamental features are not taken into account?

Answer: Basic characteristics help in grouping animals while indicating their differences. All animals do not have cell walls and are dependent on other organisms for nutrition, but mammals have special characteristics such as mammary glands.

Without these basic characteristics, it would be hard to classify because:

  • We will not be able to observe how animals are related.
  • Classification of animals would be confusing.
  • Studying how animals evolved would be harder.
NEET/JEE Offline Coaching
Get up to 90% Scholarship on your NEET/JEE preparation from India’s Leading Coaching Institutes like Aakash, ALLEN, Sri Chaitanya & Others.
Apply Now

In brief, basic characteristics are responsible for classifying animals and telling us about their evolution.


Q2. If you are given a specimen, what are the steps that you would follow to classify it?

Answer: To identify an unknown specimen, look at these most important features:

  1. Level of Organisation: Cells, tissues, or organs.

  2. Body Symmetry: Radial or bilateral.

  3. Germ Layers: Two (diploblastic) or three (triploblastic).

  4. Body Cavity: Present or absent.

  5. Coelom: True (coelomate), false (pseudocoelomate), or none (acoelomate).


Q3. How useful is the study of the nature of the body cavity and coelom in the classification of animals?

Answer: The coelom and body cavities are important in the classification of animals. A coelom is a body cavity filled with fluid, lined by embryonic tissue.

  • True coelomates are annelids, molluscs, arthropods, echinoderms, hemichordates, and chordates.
  • Animals that lack a coelom (acoelomates) are Porifera, Coelenterata (Cnidaria), ctenophores, and platyhelminths.
  • A pseudocoelom is present in some animals, which is not lined completely by mesoderm but develops from the blastocoel of the embryo.Aschelminthes fit into this category.

Dividing animals into categories according to their coelom helps us to understand their development and evolutionary history.


Q4. Distinguish between intracellular and extracellular digestion.

Answer: The differences between intracellular and extracellular digestion are as follows

Characteristics

Intracellular Digestion

Extracellular Digestion

Where Digestion Occurs

Inside cells

Outside cells, in the alimentary canal

Number of Enzymes

Few enzymes

Many enzymes

How Nutrients are Absorbed

Diffused into the cytoplasm

Absorbed across the intestinal wall into the body

Common in

Unicellular animals

Multicellular animals


Q5. What is the difference between direct and indirect development?

Answer: The differences between direct and indirect development are as follows

Direct Development

Indirect Development

No larval stages

Includes larval stages

Resemble adults

Don't resemble adults

Fishes, reptiles, birds, and mammals

Invertebrates, amphibians

Q6. What are the peculiar features that you find in parasitic Platyhelminthes?

Answer:– Platyhelminthes have several unique characteristics:

  1. They have a thick tegument that shields them from the digestive enzymes of their hosts.

  2. Their bodies are dorsoventrally flattened, i.e., flat from top to bottom.

  3. They have suckers and hooks that help them in sticking to their hosts and obtaining nutrition.

  4. They do not possess organs for movement, so they use other means to move.

  5. Their reproductive system is well developed, and they are mostly hermaphroditic, having both male and female reproductive organs.


Q7. What are the reasons that you can think of for the arthropods to constitute the largest group of the animal kingdom?

Answer: The reasons for arthropods being the largest group of animals are as follows:

  1. They have a thick cuticle that helps them to thrive in many types of environments, particularly on land.

  2. They have striated muscles that help in rapid and effective movement.

  3. They have a tracheal system of respiration that brings oxygen directly to their cells, which is extremely effective.

  4. They possess joint appendages that are capable of performing numerous different functions, so they are very adaptable.

  5. They have a highly developed nervous system and sense organs that help them effectively sense and react to their surroundings.

  6. They communicate using pheromones, which help in social behaviour and reproduction.


Q8. The water vascular system is characteristic of which group of the following:

(a) Porifera

(b) Ctenophora

(c) Echinodermata

(d) Chordata

Answer: The correct option is (c) Echinodermata

The water vascular system is a characteristic feature of echinoderms which helps in locomotion, respiration and capturing of food.


Q9. "All vertebrates are chordates but all chordates are not vertebrates." Justify the statement.

Answer: Phylum Chordata contains animals that have a notochord, i.e., an elastic rod-shaped structure. Phylum Chordata is still divided into three sub-phyla: Urochordata, Cephalochordata, and Vertebrata. During vertebrates, the notochord is superseded by a vertebral column, but within urochordates and cephalochordates, there is no vertebral column present. Therefore, all vertebrates are chordates, but they are not necessarily vertebrates, as they can also be urochordates or cephalochordates.


Q10. How important is the presence of an air bladder in Pisces?

Answer: Osteichthyes (bony fishes, such as salmon) have an air bladder, which keeps them buoyant and prevents them from sinking in water. It makes them remain at a specific depth without swimming continuously. Chondrichthyes (cartilaginous fishes, such as sharks) do not have an air bladder. They need to swim continuously, employing their fins and body to remain afloat to avoid sinking.

The air bladder functions as a buoyancy support, whereas sharks survive using motion.


Q11. What are the modifications that are observed in birds that help them fly?

Answer: Birds have some adaptations that help them to fly:

  • They have light bones with air-filled cavities, which lighten their load and reduce the effort of flying.
  • A streamlined body cuts the resistance of the air, making it move smoothly through the air.
  • Powerful flight muscles help in flapping the wings.
  • The front limbs are modified into wings for flight, and the hind limbs are used for walking and perching.
  • Additional air sacs in their body supply sufficient oxygen for extensive flights.
  • These adaptations render birds ideally suited to flight.

Q12. Could the number of eggs or young ones produced by an oviparous and viviparous mother be equal? Why?

Answer: Oviparous creatures lay eggs outside the body and generally give birth to a greater number of offspring, as they are given little parental care and exposed to severe environmental conditions. Viviparous creatures, on the other hand, give birth to live offspring and offer care both pre- and post-birth. This greater parental care leads to greater survival rates, reducing the necessity for a high number of offspring. Thus, the number of eggs or young ones given birth to by oviparous and viviparous mothers is not the same.


Q13. Segmentation in the body is first observed in which of the following:

(a) Platyhelminthes

(b) Aschelminthes

(c) Annelida

(d) Arthropoda

Answer: The correct option is (c) Annelida


Q14. Match the following:
(a) Operculum (i) Ctenophora
(b) Parapodia (ii) Mollusca
(c) Scales (iii) Porifera
(d) Comb plates (iv) Reptilia
(e) Radula (v) Annelida
(f ) Hairs (vi) Cyclostomata and Chondrichthyes
(g) Choanocytes (vii) Mammalia
(h) Gill slits (viii) Osteichthyes

Answer: (a)-(viii), (b)-(v), (c)-(iv), (d)-(i), (e)-(ii), (f)- (vii), (g)- (iii), (h)- (vi)

Operculum(viii) Osteichthyes
Parapodia(v) Annelida
Scales(iv) Reptilia
Comb plates(i) Ctenophora
Radula(ii) Mollusca
Hairs(vii) Mammalia
Choanocytes(iii) Porifera
Gill slits(vi) Cyclostomata and Chondrichthyes

Q15. Prepare a list of some animals that are found parasitic on human beings.

Answer: Taenia ( Tapeworm)

Ascaris (roundworm)

Ancylostoma (hookworm)

Enterobius (pinworm)

Wuchereria (filarial worm)


NCERT Solutions for Class 11: Subject-wise

Important Question of Class 11 Animal Kingdom

This chapter is very vast and interesting, focusing on key questions can help you understand its complexity and classification."

Question 1: The following are the statements about non-chordates:
A. gill slits perforate pharynx.
B. Notochord is absent.
C. The central nervous system is dorsal.
D. Heart is dorsal if present.
E. Post-anal tail is absent.
Choose the most appropriate answer from the options given below:

1. A & C only

2. A, B & D only

3. B, D & E only

4. B, C & D only

Answer:

In invertebrates, the notochord, a defining feature of chordates, is absent, and their body structure is often supported by other means, like exoskeletons or hydrostatic skeletons. If a heart is present, it is typically located dorsally, unlike the ventral heart found in chordates. In addition, they lack a post-anal tail, which is a characteristic feature of chordates and plays a role in locomotion or balance in those organisms.

Hence, the correct answer is option 3, B, D & E only

Also, check the NCERT Books and the NCERT Syllabus here:

Approach to Solve Questions of Class 11 Chapter 4

The approach to solving questions of this chapter involves a clear understanding of the animal kingdom. Students can follow the steps given below:

  • To understand the diversity of the animal kingdom easily, firstly, it's important to understand the classification of animals based on various features such as body symmetry, coelom, segmentation, etc.
  • Go through all the terminologies like asymmetry, radial symmetry, bilateral symmetry, and open/closed circulatory systems, to grasp the concepts effectively.
  • Prepare a table by writing down all the distinguishing features of major phyla like Arthropoda, Mollusca, Chordata, etc.
  • Study the features of these phyla using diagrams, as it will help you to understand and remember their characteristics better, and for a longer time.
  • Try to solve a lot of questions from this chapter to gain confidence while answering the questions in the exam, and to get familiar with the pattern as well.

What Extra Should Students Study Beyond the NCERT for NEET?

To do well in NEET, students should study extra topics and practice more beyond the NCERT, as shown in the table below.

Chapter Wise NCERT Solutions for Class 11 Biology

Below are the chapter-wise solutions:


Frequently Asked Questions (FAQs)

1. What are the differences between intracellular and extracellular digestion given in biology class 11?

 These are the differences between intracellular and extracellular digestion: 

   Intracellular digestion      Extracellular digestion   
The process of digestion of food takes place inside the cells  The process of digestion of food takes place outside the cells in the alimentary canal.  
Only a few enzymes are involved in the process of digestion   A number of enzymes are involved in extracellular digestion  
The products of digestion are diffused into the cytoplasm  The products of digestion across the intestinal wall into the body parts 
2. What are the benefits of NCERT solutions for class 11 biology chapter 4 animal kingdom?

NCERT Solutions for Class 11 Biology Chapter 4 Animal Kingdom make it easy for students to learn about animal classification. They give precise and correct answers to textbook questions as per the current CBSE syllabus. They explain complicated topics in an easier way, simplifying learning. They also give important diagrams and key points that help in exams. Students can quickly revise, improve their knowledge, and achieve better marks in exams using NCERT Solutions.

3. What are the important topics of NCERT solutions for class 11 biology chapter 4 animal kingdom?

The important topics of animal kingdom class 11 NCERT are:

  • Basis of Classification
  • Levels of Organisation  
  • Symmetry  
  • Diploblastic and Triploblastic Organisation  
  • Coelom  
  • Segmentation  
  • Notochord  
  • Phylum – Porifera  
  • Phylum – Coelenterata (Cnidaria)  
  • Phylum – Ctenophora  
  • Phylum – Platyhelminthes  
  • Phylum – Aschelminthes  
  • Phylum – Annelida  
  • Phylum – Arthropoda  
  • Phylum – Mollusca  
  • Phylum – Echinodermata  
  • Phylum – Hemichordata  
  • Phylum – Chordata  
4. What questions can I expect from Chapter 4 of NCERT Solutions for Class 11 Biology in the board exam?

In the board exam, questions from Chapter 4 Animal Kingdom on classification, features, and examples of various animal groups can be expected. Some main questions are:

  • Differences between coelomates, acoelomates, and pseudocoelomates
  • Features of Porifera, Cnidaria, Arthropoda, Mollusca, and Chordata
  • Adaptations in birds for flight
  • Differences between oviparous and viviparous animals
  • Special features of mammals, reptiles, and amphibians

These questions can be short answer, long answer, or diagram-based, therefore it is important to understand the key concepts to score well.

5. List some animals that are found parasitic on human beings from Chapter animal Kingdom of NCERT Solutions for Class 11 Biology.

The following list of animals found to be human parasites is taken from Chapter 4 of the NCERT Solutions for Class 11 Biology:

  • Ascaris (Roundworm)
  • Taenia (Tapeworm)
  • Enterobius (Pinworm)
  • Ancylostoma (Hookworm)
  • Wuchereria (Filarial worm)
6. What are the key features of the animal kingdom according to NCERT Class 11 Biology

Animals are multicellular, heterotrophic, and have well-developed sense organs. Most can move and respond to stimuli. They are classified based on features like symmetry and body structure.

7. How is the classification of the animal kingdom done in Class 11 Biology Chapter 4?

Classification is based on features like body symmetry, presence of a coelom, and notochord. Animals are grouped into phyla such as Porifera, Arthropoda, and Chordata.

8. What are the differences between chordates and non-chordates in Class 11 NCERT solutions?

The differences between chordates and non-chordates in Class 11 NCERT solutions are given in the table below:

Feature

Chordates

Non-Chordates

Notochord

Present at some stage

Absent

Dorsal Hollow Nerve Cord

Present

Absent

Pharyngeal Slits

Present at some stage

Absent

9. How are animals classified based on symmetry in Class 11 Biology?

Animals are classified as asymmetrical, radially symmetrical, or bilaterally symmetrical based on their body structure.

10. What are the different phyla of the animal kingdom explained in NCERT Class 11?

Major phyla include Porifera, Coelenterata, Platyhelminthes, Annelida, Arthropoda, Mollusca, Echinodermata, Hemichordata, and Chordata.

11. Why are sponges considered as primitive animals in NCERT Class 11 Chapter 4?

Sponges are considered primitive due to their simple cellular-level organization and lack of tissues or organs.

12. What are the main criteria used for classifying animals in the Animal Kingdom chapter?

Animals are classified based on features such as body organization, symmetry, coelom, level of organization, segmentation, and patterns of organ systems.


Articles

A block of mass 0.50 kg is moving with a speed of 2.00 ms-1 on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is

Option 1)

0.34\; J

Option 2)

0.16\; J

Option 3)

1.00\; J

Option 4)

0.67\; J

A person trying to lose weight by burning fat lifts a mass of 10 kg upto a height of 1 m 1000 times.  Assume that the potential energy lost each time he lowers the mass is dissipated.  How much fat will he use up considering the work done only when the weight is lifted up ?  Fat supplies 3.8×107 J of energy per kg which is converted to mechanical energy with a 20% efficiency rate.  Take g = 9.8 ms−2 :

Option 1)

2.45×10−3 kg

Option 2)

 6.45×10−3 kg

Option 3)

 9.89×10−3 kg

Option 4)

12.89×10−3 kg

 

An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range

Option 1)

2,000 \; J - 5,000\; J

Option 2)

200 \, \, J - 500 \, \, J

Option 3)

2\times 10^{5}J-3\times 10^{5}J

Option 4)

20,000 \, \, J - 50,000 \, \, J

A particle is projected at 600   to the horizontal with a kinetic energy K. The kinetic energy at the highest point

Option 1)

K/2\,

Option 2)

\; K\;

Option 3)

zero\;

Option 4)

K/4

In the reaction,

2Al_{(s)}+6HCL_{(aq)}\rightarrow 2Al^{3+}\, _{(aq)}+6Cl^{-}\, _{(aq)}+3H_{2(g)}

Option 1)

11.2\, L\, H_{2(g)}  at STP  is produced for every mole HCL_{(aq)}  consumed

Option 2)

6L\, HCl_{(aq)}  is consumed for ever 3L\, H_{2(g)}      produced

Option 3)

33.6 L\, H_{2(g)} is produced regardless of temperature and pressure for every mole Al that reacts

Option 4)

67.2\, L\, H_{2(g)} at STP is produced for every mole Al that reacts .

How many moles of magnesium phosphate, Mg_{3}(PO_{4})_{2} will contain 0.25 mole of oxygen atoms?

Option 1)

0.02

Option 2)

3.125 × 10-2

Option 3)

1.25 × 10-2

Option 4)

2.5 × 10-2

If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will

Option 1)

decrease twice

Option 2)

increase two fold

Option 3)

remain unchanged

Option 4)

be a function of the molecular mass of the substance.

With increase of temperature, which of these changes?

Option 1)

Molality

Option 2)

Weight fraction of solute

Option 3)

Fraction of solute present in water

Option 4)

Mole fraction.

Number of atoms in 558.5 gram Fe (at. wt.of Fe = 55.85 g mol-1) is

Option 1)

twice that in 60 g carbon

Option 2)

6.023 × 1022

Option 3)

half that in 8 g He

Option 4)

558.5 × 6.023 × 1023

A pulley of radius 2 m is rotated about its axis by a force F = (20t - 5t2) newton (where t is measured in seconds) applied tangentially. If the moment of inertia of the pulley about its axis of rotation is 10 kg m2 , the number of rotations made by the pulley before its direction of motion if reversed, is

Option 1)

less than 3

Option 2)

more than 3 but less than 6

Option 3)

more than 6 but less than 9

Option 4)

more than 9

Back to top