Download CBSE Class 11 Biology Chapter 4 Important Questions Free PDF
Very Short Answer Questions. (1 Mark)
1. What is mesoglea? Where is it found?
Ans: Mesoglea is an undifferentiated layer present in between ectoderm and endoderm. It is found in Coelenterates.
2. When is the development of an organism called indirect?
Ans: The development of an organism is called indirect when a larval stage (birth form) is morphologically distinct from an adult.
3. Why are corals important?
Ans: Corals have a skeleton composed of calcium carbonate which gets deposited and can lead to the formation of landforms. Example: - Lakshadweep (a coral island).
4. What is the difference between class Amphibia and class Reptilia in respect of their skin?
Ans: The difference between amphibia and reptilia are:
5. Which phylum consists of organisms with a cellular level of organisation?
Ans: Phylum Porifera consists of organisms with a cellular level of organisation. Example: - Sponges
6. Name the arthropod which is an (i) Living fossil, (ii) Gregarious pest.
Ans:
(i) Living fossil: - Limulus (King crab),
(ii) Gregarious pest: - Locusta (Locust).
7. Which organ helps in excretion in (i) Arthropods, (ii) Hemichordates?
Ans:
(i) Organs of excretion in Arthropods: - Malpighian tubules,
(ii) Organs of excretion in Hemichordates: - Proboscis gland.
8. Name an example of egg-laying mammals.
Ans: The duck-billed platypus is an example of an egg-laying mammal.
9. What is polymorphism?
Ans: The phenomenon when an organism has different kinds of zooids for different functions is called polymorphism.
10. Which animal is popularly called ploughman of nature & why?
Ans: Earthworms are popularly referred to as ploughmen of nature (or friends of farmers) because they bring subsoil to the surface and create fine burrows for aeration.
11. What are the organs of excretion in annelids & insects?
Ans:
(i) Organs of excretion in annelids: - Nephridia
(ii) Organs of excretion in insects: - Malpighian tubules
12. Name a free-living & parasitic Platyhelminthes.
Ans:
(i) Free-living Platyhelminthes: – Planaria (Freshwater flatworm)
(ii)Parasitic Platyhelminthes: – Taenia (Tapeworms)
13. Name two adaptations for an aerial mode of life.
Ans: Two adaptations for an aerial mode of life are: -
(i) Forelimbs are modified into wings.
(ii) Uricotelic excretion & pneumatic bones.
14. Name the organs of defence in paramecium.
Ans: Trichocysts are organs of defence in paramecium.
15. Name the second largest animal phylum.
Ans: Mollusca is the second-largest animal phylum.
16. What are acoelomate animals?
Ans: The animals which do not have a coelom or body cavity are called acoelomate animals. Examples are Porifera, coelenterates and flatworms.
17. Name the larva found in Mollusca & Annelid.
Ans: The larva found in Mollusca and Annelida is the Trochophore larva.
18. Name two viviparous fishes.
Ans: Pristis (Sawfish) and scoliodon (Dogfish)are two viviparous fishes.
19. What are flame cells?
Ans: Flame cells are excretory organs found in Platyhelminthes and related animals. They have flickering cilia or flagella that move the absorbed excretory products into a system of ducts.
20. Name a vertebrate in which jaws are absent.
Ans: Petromyzon (Sea lamprey) is a vertebrate in which jaws are absent.
21. Assign the phylum to which the following animals belong – pheretima & sponge.
Ans: Pheretima belongs to phylum Annelida & sponge belongs to phylum Sponge (Porifera).
22. What is metamerism?
Ans: In some Bilateria, the body consists of many segments & shows repetitions of parts. This type of segmentation is called metamerism.
Short Answer Questions (2 Marks)
1. Distinguish between poikilotherms and homeotherms organisms.
Ans: The difference between poikilotherms and homeotherms organisms are:
2. Define metagenesis with a suitable example.
Ans: Metagenesis is the phenomenon of alternation of generations between sexual and asexual modes of reproduction. Cnidarians have two forms in their life cycle: - the polyp form and the medusa form. Polyps (sporophyte) produces medusa asexually whereas the medusa (gametophyte) produces the polyp sexually. Example: - Obelia.
3. List any four identifying features of Arthropoda & give examples.
Ans: Four identifying features of Arthropoda are: -
(i) Animals with jointed appendages;
(ii) Triploblastic, coelomate, and bilaterally symmetrical animals;
(iii) The body of animals is covered by a chitinous cuticle (hard exoskeleton), and segments are not separated by septa.
(iv) Arthropods are unisexual animals.
(v) Examples include Crab, Apis, Spider and Anopheles.
4. Distinguish between diploblastic & triploblastic animals.
Ans: The difference between diploblastic and triploblastic animals are:
5. What are protochordates? How is it classified?
Ans: Protochordate is an organism that belongs to the lower chordates and is generally found in marine water. Their body is bilaterally symmetrical, triploblastic, and coelomate. At a certain stage of their lives, their bodies develop a long, rod-like structure called the notochord. There are three subphyla: -
(i) Hemichordata (Half chordate)
Example: - Balanoglossus
(ii) Urochordata (Tail cord)
Example: - Salpa & Herdmania
(iii) Cephalochordata (Head cord)
Example: - Amphioxus
6. Mention the unique features of nematodes.
Ans: The unique features of nematodes are: -
(i) Syncytial (no mesodermal lining).
(ii) Body wall musculature is made of special types of muscles.
(iii) Sexual dimorphism is quite clear.
(iv) Their body is triploblastic and bilaterally symmetrical.
(v) They are generally cylindrical in shape.
(vi) Their body has a false cavity (pseudocoelomate).
(vii) The alimentary canal is distinct, having the mouth and the anus.
7. Point out differences between dogfish & catfish.
Ans: The differences between a dogfish and catfish are:
8. Outline the role of the coelom in animals.
Ans: The coelom is the space between the body wall & the alimentary canal of organisms. It is lined by mesoderm. Visceral organs lie in the coelom. Flatworms do not have a coelom. Hence, they are called acoelomates. Pseudocoelom is found in the roundworm. Annelids are coelomate animals.
9. Mention the unique features of the phylum Mollusca.
Ans: Unique features of phylum Mollusca are: -
(i) Body soft as well as unsegmented.
(ii) The body is covered by a calcareous shell and mantle.
(iii) The body is divided into - head, visceral mass and foot.
(iv) Buccal mass possesses radula.
Figure: Unique features of Mollusca
10. Distinguish between insects & Arachnida.
Ans: The difference between insects and arachnids are:
11. Why are echinoderms considered closer to chordates than any other phylum?
Ans: Echinoderms are considered closer to chordates because, like chordates, they are deuterostomes i.e., the anal region develops earlier than the mouth region. Their larvae are also closer to protochordate.
12. Distinguish between bony fish & cartilaginous fish.
Ans: The difference between bony fish and cartilaginous fish are:
13. Give the reason why a snail & an octopus are classified under the same phylum?
Ans: Snails and octopus are classified under the phylum Mollusca due to the following three common characteristics: -
(i) Presence of a mantle cavity for respiration and excretion etc.
(ii) Presence of radula for feeding.
(iii) Presence of foot and shell.
14. List three basic chordate characters.
Ans: The three basic characters of chordates are: -
(i) Notochord: - A dorsal solid notochord is present throughout life or within the larval stage.
(ii) Nerve cord: - A hollow nerve cord is present dorsally.
(iii) Pharyngeal gill slits: - A perforated pharynx is present in young conditions or throughout life.
15. Give any four characteristics of hemichordate.
Ans: The four characteristics of hemichordate are: -
(i) These are worm-like marine animals that have an organ-system level of organization.
(ii) Their body is bilaterally symmetrical, triploblastic and coelomate (having true coelom).
(iii) The body is cylindrical and is divided into anterior proboscis, collar and a long trunk.
(iv) Respiration occurs through gills.
16. Distinguish between centipede & millipede.
Ans: The difference between centipede and millipede are:
17. Give the reason why Arthropoda constitute the largest group of the animal kingdom.
Ans: Arthropoda constitutes the largest group of the animal kingdom: -
(i) Have an organ level of organization.
(ii) Bilaterally symmetrical, segmented, triploblastic, coelomate animals.
(iii) Body enclosed by the chitinous cuticle.
(iv) They have jointed appendages.
(v) Trachea or book gills for respiration.
18. Differentiate between male & female Ascaris.
Ans: The difference between male and female Ascaris are:
19. List three adaptations that help the birds (Aves) in flying.
Ans: The three adaptations that help the birds (Aves) in flying are: -
(i) Lightweight smooth feathers.
(ii) Flight muscles contain white fibres which are poorer in mitochondria and lack myoglobin.
(iii) The long bones are hollow (Pneumatic bones) and filled with air.
20. List the characteristic features of class Mammalian.
Ans: The characteristic features of class Mammalian are: -
(i) These animals are warm-blooded (homeotherms), hairy, and have mammary glands, which produce milk.
(ii) Oil glands and sweat glands are present in their skin.
(iii) The skull is dicondylic, i.e., it has two occipital condyles.
(iv) The lungs are responsible for respiration.
(v) The heart has four chambers.
Short Answer Question (3 Marks)
1. What are the features of Class Aves that help them for flying?
Ans: The features of class Aves that help them in flying are - lightweight smooth feathers, long bones (pneumatic bones) with internal spaces filled with air, air sacs connected to lungs to supplement respiration and streamlined shape of the body.
2. “All vertebrates are chordates but all chordates are not vertebrates” justify the statement.
Ans: All vertebrates are chordates because they possess three basic chordate features:
(i) All chordates possess a dorsal solid notochord throughout life or in the larval stage.
(ii) All chordates possess a dorsal hollow nerve cord.
(iii) All chordates have pharyngeal gill slits in some stages of the life cycle.
All chordates are not vertebrates. Vertebrates have vertebral columns but protochordate and agnatha have notochord that is not replaced by the vertebral column.
3. “Mammals are the most successful & dominant animals today” Give evidence.
Ans: Mammals are the most successful and dominant animals on the planet today. They thrive in the majority of the world's environments. The unique characteristics of mammals are: -
(i) Body covered with hair.
(ii) Presence of sweat and sebaceous glands in the skin.
(iii) Presence of mammary glands in females that produce milk.
(iv) Presence of a pair of external ears and three ear ossicles i.e., malleus, incus and stapes.
(v) The heart has four chambers.
(vi) RBCs are biconcave and lack a nucleus (enucleated).
(vii) The testis is located outside the abdomen in a special pouch called the scrotum.
(viii) Mostly viviparous (produces young ones).
(ix) The embryo is attached to the uterine wall with the help of the placenta.
(x) The skull is dicondylic, i.e., it has two occipital condyles.
4. Enlist the main characteristics & examples of phylum Porifera.
Ans: The main characteristics of phylum Porifera are: -
(i) They are commonly known as sponges.
(ii) They are generally marine.
(iii) Their body is diploblastic and bilaterally symmetrical.
(iv) They possess a water transport mechanism.
(v) They are extremely primitive multicellular animals with a cellular level of organisation.
(vi) Water can enter by pores called Ostia in the body wall directly or through the canal into the spongocoel. It goes out through the osculum. It is known as the canal system.
(vii) The body is supported by a skeleton that consists of spicules
(viii) Sexes are not separate.
(ix) They reproduce asexually by fragmentation.
(x) They also reproduce sexually by the formation of gametes.
(xi) Fertilization is internal.
(xii) Example- Euplectella, Spongilla, Sycon, Euspongia etc.
5. What is the basis of the classification of Animalia?
Ans: The basis of classification of Animalia are: -
(i) Notochord: - It is a rod-like structure found in the chordates. It is not found in non-chordates.
(ii) Symmetry: - It is the plan of arrangement of body parts. They are of three types: - Asymmetrical, radially symmetrical, and bilaterally symmetrical.
(iii) Organisation: - Animals have a cellular grade of organisation. Their bodies are made up of cells, while others have tissues, organs, and organ systems.
Embryonic layers: - Ectoderm, mesoderm and endoderm are three embryonic layers that give rise to different organs in the body. These are also called germinal layers. Some animals are diploblastic, for example-sponges, but others are triploblastic having three germinal layers.
6. Give important characters of phylum Nemathelmintnes.
Ans: The important characters of phylum Nemathelmintnes are: -
(i) They are commonly known as nematodes or roundworms.
(ii) Their body is covered by a cuticle.
(iii) Their body is bilaterally symmetrical.
(iv) Animals have elongated cylindrical and spindle-shaped bodies with pointed ends.
(v) The body cavity is pseudocoelomate (false coelom).
(vi) There is no muscle layer in the alimentary canal.
(vii) There is no respiratory organ or blood vascular system.
(viii) Example – Ascaris, Rhabditis and Ancylostoma.
7. Members of which phylum are known as “segmented worm” Write about their body symmetry, mode of excretion & respiration.
Ans: Members of the phylum Annelida are also referred to as segmented worms. Their body is metamerically segmented. Example: - Nereis, Pheretima and Hirudinaria.
(i) Body Symmetry: - Segmented worms have typical metameric segmentation. Their body consists of segments called metamere or somites and ring-like grooves called annuli.
(ii) Excretion: - The excretory unit is coiled tubules called nephridia.
(iii) Respiration: - Respiration occurs by means of gills or skin. The skin is supplied with a large number of blood vessels. It is permeable and plays an important role in the exchange of gases.
8. Differentiate between Annelida & Arthropoda.
Ans: The difference between Annelida and Arthropoda are:
9. What are the basic plans of body design in animals?
Ans: Animals can be classified into three basic plans:
(i) Cell Aggregate Plan: - It is found in simple animals such as sponges, which have clusters of cells with the rudimentary division of labour.
(ii) Blind Sacs Plan: - It is found in coelenterates and flatworms. They have a digestive cavity with only one opening to the outside world. Food is ingested and undigested waste is expelled through this opening in the mouth. The cells are more specialised and have a division of labour.
(iii) Tube- within a tube plan: - It is found in more complex forms. In this plan, the body cavity forms one tube within which another tube, the alimentary canal, is located, opening on one side by the mouth and the other by the anus.
10. Mention the important characters of the phylum Echinodermata and give examples.
Ans: The important characters of phylum Echinodermata are: -
(i) The term Echinodermate means "spiny skin," and it refers to a group of animals represented by common forms such as starfish and sea urchins.
(ii) The skin forms a hard, spiny protective skeletal covering.
(iii) They are sluggish marine forms.
(iv) They usually show pentamerous radial symmetry.
(v) The radial symmetry is superficial and the body in fact can be divided only into two halves.
(vi) They have a coelom as well as a water vascular system.
(vii) Locomotion takes place through the use of numerous hollow tube feet.
(viii) Excretion occurs by means of diffusion through the body.
(ix) Fertilization occurs in the open sea.
(x) The development includes free swimming diploneural larva.
(xi) Example: - Asterias, Sea Urchin and Sea cucumber.
11. Give three important distinguishing characters of arthropods, reptiles and mammals.
Ans: Three important distinguishing characters of arthropods, reptiles and mammals are:
(i) Arthropods: - Arthropods have jointed appendages, segmented bodies divided into the head, thorax, and abdomen, a hard non-living chitinous exoskeleton, and compound eyes. Example: - Insects, centipedes, etc.
(ii) Reptiles: - They are cold-blooded, the body is covered by scales, possess two pairs of limbs and lay eggs. Example: - Lizard, snake etc.
(iii) Mammals: They are warm-blooded, have a hairy body, an external ear, give birth to young, have small pointed teeth, and a long snout. Example: - Dog, monkey, lion etc.
12. Mention the important characteristics of coelenterate and give examples.
Ans: The important characteristics of coelenterates are: -
(i) They are marine animals that may be solitary or colonial.
(ii) The body consists of two germ layers, the ectoderm and endoderm (diploblastic).
(iii) Their body is radially symmetrical.
(iv) They are acoelomate animals i.e., lack true coelom. They exhibit a blind sac body plan.
(v) They have a holozoic form of nutrition.
(vi) The body encloses a large central cavity known as coelenteron, which has a single opening to the outside. Coelenterons is also known as a gastrovascular cavity.
(vii) They have either intracellular or extracellular modes of digestion.
(viii) They commonly show polymorphism. There are two types of individuals: a polyp (asexual form) and a medusa (sexual form).
(ix) They have tentacles, which are usually thread-like outgrowths.
(x) Stinging cells or nematocysts are present.
(xi) Their larvae are ciliated and free-swimming.
(xii) Example: - Obelia, Aurelia, Hydra, Metridium etc.
Figure: Alteration of generation in coelenterates
13. Differentiate between flightless and flying birds.
Ans: The difference between flightless and flying birds are:
Long Answer Questions (5 Marks)
1. How are non-chordates different from chordates? Write the major phyla of non-chordate and give examples.
Ans: The non-chordates are different from chordates in the following ways:
The following are the major phyla of non-chordates: -
(i) Phylum Porifera: - They are commonly known as sponges. They are generally marine; the body is diploblastic and bilaterally symmetrical. They possess a water transport mechanism. Example- Euplectella, Spongilla, Sycon and Euspongia etc.
(ii) Phylum Coelenterata: - They are marine animals. Their body is radially symmetrical, diploblastic and acoelomate. They exhibit a blind sac body plan. They commonly show polymorphism. There are two types of individuals: a polyp (asexual form) and a medusa (sexual form). Example: - Obelia, Aurelia, Hydra and Metridium etc.
(iii) Phylum Platyhelminthes: - Their body is dorsoventrally flattened and exhibits bilateral symmetry. They are triploblastic and acoelomate. Their body is soft and unsegmented. They are mostly parasitic in nature. Example: - Taenia (Tapeworms), Fasciola (Liver fluke) and Taenia saginata (Beef tapeworm).
(iv) Phylum Nematoda: - They are generally cylindrical in shape. Body wall musculature is made of special types of muscles. Sexual dimorphism is quite clear. Their body is triploblastic, bilaterally symmetrical and has a false cavity (pseudocoelomate). The alimentary canal is distinct, having the mouth and the anus. Example: - Ascaris and Enterobius.
(v) Phylum Annelida: - They are coelomate, triploblastic and exhibit organ system level organization. Their body is elongated and metamerically segmented. They have a well-developed circulatory and digestive system. They respire through their body surface and the excretory organs are Nephridia. Example: - Earthworm, Leeches, Lugworms and Polychaetes.
(vi) Phylum Arthropoda: - They have an organ level of organization. Their body is bilaterally symmetrical, segmented, triploblastic and coelomate. They have jointed appendages and the body is enclosed by the chitinous cuticle. They possess trachea or book gills for respiration. Example: - Lobsters, Crabs and Spiders.
(vii) Phylum Mollusca: - They are bilaterally symmetrical and triploblastic. They have an organ-system level of organization. Their body is soft, unsegmented and covered by a mantle and shell. Their body is divided into three main regions – head, a visceral mass, and ventral foot. Example: - Clams, Octopus, Mussels, Pila and Oyster.
(viii) Phylum Echinodermata: - They are sluggish marine forms. Their skin forms a hard, spiny protective skeletal covering. They usually show pentamerous radial symmetry. They have a coelom as well as a water vascular system. Locomotion takes place through the use of numerous hollow tube feet. Example: - Sea Urchins and Seastar.
2. Enlist the main features of Aschelminthes and give examples.
Ans: The main features of Aschelminthes are: -
(i) They are called roundworms as they appear circular in C.S.
(ii) Free-living, aquatic, terrestrial or parasitic.
(iii) The organization of the body is organ level.
(iv) Bilaterally symmetrical animals.
(v) They are triploblastic and pseudocoelomate.
(vi) Alimentation is complete with the muscular or pharynx.
(vii) Sexes are Separate.
(viii) The body is covered by a cuticle.
(ix) Fertilization is internal.
(x) Example: - Filarial worm (Wuchereria), Ascaris, Pinworm (Enterobius) and Hookworm (Ancylostoma).
Figure: Male and female Ascaris
3. Enlist the main salient features of phylum Ctenophora.
Ans: The main salient features of phylum Ctenophora are:
(i) Ctenophores are marine animals having transparent and flat or oval body shapes.
(ii) The polyp phase is absent in the life cycle of ctenophores.
(iii) These are bilaterally symmetrical and lack cnidoblast cells.
(iv) When the tentacles are present, they are two in number and contain colloblast cells.
(v) They move by cilia which join together to form comb plates. There are eight median comb plates.
(vi) The gastrovascular cavity is branched and open to the outside by the stomodeum.
(vii) They are diploblastic, but the mesoglea differs from that of cnidaria.
(viii) The presence of special sense organs at the opposite end of the mouth is the main characteristic of this phylum.
(ix) They reproduce only by means of sexual reproduction.
(x) They do not have a larval phase in their life cycle.
(xi) Example: -Ctenophora (Pleurobrachia), ctenophore, ctenoplana, Beroe and Hormiphora.
Figure: Ctenophora
Download Important Questions of Animal Kingdom Class 11 PDF
Topics covered in Class 11 Biology Chapter 4 important questions are:
Animals features and basis of classification
Levels of the organization
The symmetry of animals
Coelom
Notochord
Segmentation
The study of different types of the phylum.
Class 11 Biology Chapter 4 - Animal Kingdom Summary
The animal kingdom is one of the five-kingdom proposed by R.H. Whittaker and it comprises multicellular eukaryotic organisms that do not possess a cell wall. As millions of species are described till now of different structures and forms. The classification was very necessary for the systematic positioning of newly described species.
Basis of Classification - Animal kingdom is classified based on the different essential characteristics like level of organization, habitat, and symmetry. There are different levels of organization such as the cellular level of organization, tissue level of the organization, organ level of organization, and the organ system level of organization.
There are different patterns of the organ system like the digestive system, in which some might be complete and others can be an incomplete digestive system. Circulatory system, open type, and closed type. The symmetry of the animal is of three types bilateral symmetry, radial symmetry, and asymmetrical.
Coelom - The body cavity which is lined by the mesoderm is known as a coelom. Some of the classifications are made on the presence and absence of coelom. On the basics of the coelom, animals can be divided into three different types: coelomates, pseudocoelomates, and coelomates.
Mainly animals have three types of the body like cell aggregate body plan, this type of body plan is found in the sponges. Blind sac body plan and is found in the coelenterates, flatworms, and ctenophores. And the third one is a tube within the tube body plan and it is found in the aschelminthes.
Segmentation - Body of some of the animals are divided into segments externally, as well as internal or some of them with a serial repetition of at least some organs. Segmentation can be mainly of two types: metameric segmentation and pseudo metameric segmentation. Metameric segmentation divides the body both externally as well as internally and in pseudo metameric segmentation, the body is divided into parts or segments.
Practice Questions for CBSE Class 11 Biology Chapter 4: Animal Kingdom
Very Short Answer Type Questions
Define permanent tissues.
Write three different types of meristematic tissue.
Which cell is responsible for curling the leaves in plants during water stress?
Short Answer Type Questions
Why are phloem and xylem considered as complex tissues?
Write the difference between guard cell and epidermal cell.
Define guard cells.
Long Answer Type Questions
Explain the secondary growth in roots with a diagram.
What are monocotyledonous plants?
What is the difference between dicot roots and monocot roots?
Extra Questions for Practice
What are bulliform cells?
What are guard cells and epidermal cells?
Explain Hutchinson’s system of classification?
Define Mesophyll.
Define Pith.
Benefits of Solving CBSE Class 11 Biology Chapter 4 Important Questions
Following are some of the benefits of solving CBSE Class 11 Biology Chapter 4 Important Questions
Practising important questions will give students an overall idea about the important topics of the chapter.
Students can enhance their time management skills by solving important questions in a given time period.
Solving various types of questions for this chapter will enhance their problem-solving skills.
Students will be aware of the difficulty level of the questions, and the way questions can be framed in the exam
Practising questions repeatedly will enhance their confidence level.
Students will be able to handle any type of question in the exam, even the complex ones.
Conclusion
CBSE Class 11 Biology Chapter 4 important questions are the perfect study material for the students to get a strong hold on the important concepts. Practising the questions repeatedly will surely help students to confidently attempt questions in less time during exams. Apart from Class 11 Biology Chapter 4 important questions, Vedantu also provides Class 11 Chapter wise and Subject wise important questions. Explore the website to get the Class 11 Chapter wise and Subject wise important questions.
Related Study Materials for Class 11 Biology Chapter 4
CBSE Class 11 Biology Chapter-wise Important Questions
CBSE Class 11 Biology Chapter-wise Important Questions and Answers cover topics from all 19 chapters, helping students prepare thoroughly by focusing on key topics for easier revision.
Additional Study Materials for Class 11 Biology
FAQs on CBSE Important Questions for Class 11 Biology Chapter 4- Animal Kingdom
1. What are the most important topics within Chapter 4, Animal Kingdom, for the CBSE Class 11 Biology exam 2025-26?
For the 2025-26 exams, focus on the basis of classification (coelom, symmetry, segmentation) and the salient features of major phyla. Specifically, Phylum Arthropoda (largest phylum), Phylum Chordata, and the comparison between classes Chondrichthyes and Osteichthyes are high-weightage topics often appearing in 3 and 5-mark questions.
2. How can I score full marks on a question that asks to differentiate between Chordates and Non-chordates?
To score full marks, present the differences in a tabular format. Key points to include are:
- Notochord: Present in Chordates, absent in Non-chordates.
- Central Nervous System: Dorsal, hollow, and single in Chordates; ventral, solid, and double in Non-chordates.
- Pharynx: Perforated by gill slits in Chordates.
- Heart: Ventral in Chordates, dorsal (if present) in Non-chordates.
- Post-anal Tail: Present in Chordates, absent in Non-chordates.
3. What are some expected 3-mark questions from the phyla Platyhelminthes and Aschelminthes?
Important questions often focus on comparative features that highlight evolutionary advancements. For instance:
- List three distinguishing features of Phylum Platyhelminthes with examples.
- Explain the concept of a 'tube-within-a-tube' body plan with reference to Aschelminthes.
- Differentiate between Platyhelminthes and Aschelminthes based on their coelom, body symmetry, and level of organisation.
4. Why is the basis of classification considered a critical topic for exams, and not just the phyla descriptions?
The basis of classification is crucial because it forms the foundation for all comparative questions in the exam. Examiners use this topic to test your understanding of evolutionary relationships between different animal groups. Questions are designed to see if you can link features like the presence of a true coelom or bilateral symmetry to an animal's complexity and its position in the kingdom. Simply memorising phyla features without understanding these fundamentals leads to incomplete answers.
5. What is a common mistake students make when answering questions about Phylum Arthropoda?
A common mistake is only mentioning that it's the "largest phylum" and listing "jointed appendages." To score well, you must elaborate on the reasons for its success. Important points to include are the presence of a versatile chitinous exoskeleton, a segmented body (head, thorax, abdomen), and well-developed sensory organs like antennae and compound eyes. Forgetting to mention the diverse respiratory organs (gills, book gills, book lungs, tracheal system) is another frequent error.
6. What kind of Higher-Order Thinking Skills (HOTS) questions can be framed from the comparison of classes within Vertebrata?
HOTS questions often require you to apply knowledge. For example, a question might be, "All vertebrates are chordates, but all chordates are not vertebrates. Justify this statement with examples from the subphyla Urochordata and Cephalochordata." Another typical HOTS question could be to explain the evolutionary significance of the development of an amnion, which led to the success of Reptiles, Aves, and Mammals on land compared to Amphibians.
7. From an exam perspective, what are the three key distinguishing features between Class Aves and Class Mammalia?
While both are warm-blooded, the key distinguishing features for exams are:
- Integument: Aves have an exoskeleton of feathers, while Mammals are characterised by the presence of hair or fur.
- Reproduction: Aves are oviparous (lay eggs), whereas most Mammals are viviparous (give birth to live young) and possess mammary glands to nourish their young.
- Forelimbs: In Aves, the forelimbs are modified into wings for flight. In Mammals, forelimbs are adapted for various functions like walking, running, swimming, or grasping.
8. Are MCQs and very short answer questions from Animal Kingdom important for the final exam?
Yes, they are very important. This chapter is rich in terminology and specific examples, making it ideal for objective-type questions. Expect questions on the specific level of organisation (e.g., cellular, tissue), type of coelom (acoelomate, pseudocoelomate, coelomate), or a unique feature of a minor phylum (e.g., the water vascular system in Echinodermata or bioluminescence in Ctenophora). These questions test your precise knowledge and can significantly impact your overall score.
