Diversity in the Animal Kingdom — ICSE Class 9 Biology Important Questions
15 ICSE Class 9 Biology practice questions on Diversity in the Animal Kingdom, each with a full model answer, covering 4 topics from the chapter in the question formats used in the exam.
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Reviewed by Classmate AI Team · 18 October 2026
Last updated 25 October 2026
- 15
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- Key concepts
- ₹0
- With answers
ICSE Class 9 Diversity in the Animal Kingdom questions cover the eight non-chordate phyla from Porifera to Echinodermata (with their main features and examples), how chordates differ from non-chordates, and the five classes of vertebrates (Pisces, Amphibia, Reptilia, Aves and Mammalia), including identifying specimens from a diagram as in the practical.
About Diversity in the Animal Kingdom
Within the ICSE Class 9 Biology chapter Diversity in the Animal Kingdom you study Kingdom Animalia: the non-chordates, from Porifera to Echinodermata, and the chordates, with all five classes of vertebrates. You learn the main feature and typical examples of each group so you can place a given animal or specimen in its phylum or class. This unit replaces Five Kingdom Classification from the ICSE 2028 examination.
Key concepts & formulas
Animals without a notochord, in eight phyla: Porifera (pores), Coelenterata (tentacles), Platyhelminthes (flat body), Nemathelminthes (round body), Annelida (ring-like segments), Arthropoda (jointed legs), Mollusca (soft body, shell) and Echinodermata (spiny skin, tube feet).
Animals with a notochord, a dorsal hollow nerve cord and gill slits at some stage of life. In vertebrates the notochord is replaced by a backbone.
Pisces (scales, gills), Amphibia (moist skin, tadpole larva), Reptilia (dry scaly skin), Aves (feathers, wings) and Mammalia (hair, mammary glands). Birds and mammals are warm-blooded; the other three are cold-blooded.
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Important questions with answers
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Multiple-choice questions (1 mark)
The animals whose body wall has many small pores (ostia) through which water enters, and which are mostly fixed to rocks, belong to the phylum:
- (a)
Porifera
- (b)
Coelenterata
- (c)
Annelida
- (d)
Mollusca
Show model answer
Answer: (a) Porifera.
Porifera means 'pore-bearing'. Sponges such as Sycon and Spongilla draw water in through the ostia and pass it out through a larger opening, the osculum.
Jointed legs and a hard outer covering of chitin (exoskeleton) are the main features of the phylum:
- (a)
Annelida
- (b)
Mollusca
- (c)
Arthropoda
- (d)
Echinodermata
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Answer: (c) Arthropoda.
Arthropoda means 'jointed legs'. Cockroach, prawn, spider and scorpion are examples; it is the largest phylum of the animal kingdom.
Tube feet worked by a water vascular system, a spiny skin and a body with five arms are found in:
- (a)
octopus
- (b)
jellyfish
- (c)
crab
- (d)
starfish
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Answer: (d) starfish.
The starfish is an echinoderm. All echinoderms are marine, have a spiny skin and move with tube feet operated by the water vascular system.
Which pair is wrongly matched?
- (a)
Pisces: two-chambered heart
- (b)
Amphibia: moist skin without scales
- (c)
Aves: cold-blooded
- (d)
Mammalia: mammary glands
Show model answer
Answer: (c) Aves: cold-blooded.
Birds, like mammals, are warm-blooded: they keep a constant body temperature. Fishes have a two-chambered heart, amphibians have moist skin without scales, and mammals have mammary glands, so the other three pairs are correct.
Assertion–Reason questions (1 mark)
Assertion (A): The whale is placed in class Mammalia and not in class Pisces.
Reason (R): The whale breathes through lungs and feeds its young on milk from mammary glands.
- (a)
Both A and R are true and R is the correct explanation of A
- (b)
Both A and R are true but R is not the correct explanation of A
- (c)
A is true but R is false
- (d)
A is false but R is true
Show model answer
Answer: (a) Although it lives in water and has a fish-like shape, the whale breathes air through lungs, is warm-blooded and suckles its young. These are mammalian features, so R correctly explains A.
Assertion (A): The earthworm is placed in phylum Annelida.
Reason (R): The earthworm has jointed legs.
- (a)
Both A and R are true and R is the correct explanation of A
- (b)
Both A and R are true but R is not the correct explanation of A
- (c)
A is true but R is false
- (d)
A is false but R is true
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Answer: (c) A is true: the earthworm's long body is divided into ring-like segments, the mark of Annelida. R is false: it has no legs at all and moves with the help of tiny bristles called setae. Jointed legs belong to Arthropoda.
Very short answer questions (2 marks)
Name the phylum to which each animal belongs: (a) Hydra, (b) Ascaris, (c) tapeworm, (d) octopus.
Show model answer
(a) Hydra: Coelenterata.
(b) Ascaris (roundworm): Nemathelminthes.
(c) Tapeworm: Platyhelminthes.
(d) Octopus: Mollusca.
State two differences between chordates and non-chordates.
Show model answer
| Chordates | Non-chordates |
|---|---|
| A notochord is present at some stage of life | No notochord at any stage |
| A dorsal, hollow nerve cord | Nerve cord, where present, is ventral and solid |
(Any two; another accepted difference: gill slits in the throat region at some stage in chordates, never in non-chordates.)
Name the class of each animal: (a) bat, (b) penguin, (c) salamander, (d) tortoise.
Show model answer
(a) Bat: Mammalia (body hair, feeds young on milk; it flies but is not a bird).
(b) Penguin: Aves (feathers and a beak; it cannot fly but is still a bird).
(c) Salamander: Amphibia (moist skin without scales).
(d) Tortoise: Reptilia (dry scaly skin, shelled eggs laid on land).
Short answer questions (3 marks)
Study the specimens A, B and C below.
For each specimen, (i) name it, (ii) name its phylum and (iii) give one feature visible in the diagram that places it in that phylum.
Show model answer
| Specimen | Name | Phylum | Visible feature |
|---|---|---|---|
| A | Hydra | Coelenterata | Tubular body with a ring of tentacles round the mouth (a bud grows on the side) |
| B | Earthworm | Annelida | Long body divided into ring-like segments (thick band: clitellum) |
| C | Starfish | Echinodermata | Five arms from a central disc and a spiny skin |
Distinguish between Platyhelminthes, Nemathelminthes and Annelida with respect to (i) body shape, (ii) segmentation and (iii) one example each.
Show model answer
| Feature | Platyhelminthes | Nemathelminthes | Annelida |
|---|---|---|---|
| Body shape | Flat, leaf- or ribbon-like (flatworms) | Round, thread-like, tapering at both ends (roundworms) | Long and cylindrical |
| Segmentation | Not segmented | Not segmented | Divided into ring-like segments |
| Example | Tapeworm, liver fluke, Planaria | Ascaris, hookworm | Earthworm, leech |
Which of the five classes of vertebrates are cold-blooded and which are warm-blooded? Give the number of chambers in the heart of each class.
Show model answer
Cold-blooded (body temperature changes with the surroundings): Pisces, Amphibia and Reptilia.
Warm-blooded (constant body temperature): Aves and Mammalia.
| Class | Heart chambers |
|---|---|
| Pisces | 2 |
| Amphibia | 3 |
| Reptilia | 3 (4 in crocodiles) |
| Aves | 4 |
| Mammalia | 4 |
Long answer questions (5 marks)
Give one main characteristic and one example of each of the eight non-chordate phyla from Porifera to Echinodermata.
Show model answer
| Phylum | Main characteristic | Example |
|---|---|---|
| Porifera | Body with many pores; mostly marine and fixed | Sponge (Sycon) |
| Coelenterata | Hollow body; tentacles with stinging cells round the mouth | Hydra, jellyfish |
| Platyhelminthes | Flat body; many are parasites | Tapeworm |
| Nemathelminthes | Round, unsegmented body pointed at both ends | Ascaris |
| Annelida | Body of ring-like segments | Earthworm |
| Arthropoda | Jointed legs and a chitin exoskeleton | Cockroach |
| Mollusca | Soft, unsegmented body, usually inside a hard shell; a muscular foot | Snail |
| Echinodermata | Spiny skin, tube feet; all marine | Starfish |
Describe the five classes of vertebrates under the headings: body covering, organ of breathing, and one example.
Show model answer
| Class | Body covering | Breathing | Example |
|---|---|---|---|
| Pisces | Scales | Gills | Rohu, shark |
| Amphibia | Moist, glandular skin without scales | Gills in the tadpole; lungs and moist skin in the adult | Frog, toad |
| Reptilia | Dry skin with horny scales | Lungs | Lizard, snake |
| Aves | Feathers | Lungs (with air sacs) | Pigeon, sparrow |
| Mammalia | Hair (fur) | Lungs | Human, cow |
All five have a backbone (vertebral column), which is why they are called vertebrates.
Case-based questions (4 marks)
On a school trip to the seashore, students recorded these animals: a sponge fixed to a rock, a jellyfish, a crab, an octopus, a starfish and a fish.
(i) Which of these is a chordate? (ii) Which one has jointed legs, and what is its phylum? (iii) Name the phylum of the octopus and give one of its features. (iv) Why is the sponge placed in Porifera?
Show model answer
(i) The fish. It has a backbone and belongs to class Pisces; all the others are non-chordates.
(ii) The crab, phylum Arthropoda.
(iii) Mollusca: a soft, unsegmented body (the octopus has no outer shell).
(iv) Its body wall is full of pores (ostia) through which water enters; Porifera means 'pore-bearing'.
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Frequently asked questions
What are the important questions in Diversity in the Animal Kingdom ICSE Class 9?
The eight non-chordate phyla from Porifera to Echinodermata with examples, chordates versus non-chordates, and the five vertebrate classes, including identifying specimens. This page has 15 such questions with answers, including a seashore-trip case study.What are the eight non-chordate phyla?
Porifera (sponges, with pores), Coelenterata (Hydra, with tentacles), Platyhelminthes (tapeworm, flat), Nemathelminthes (Ascaris, round), Annelida (earthworm, ringed segments), Arthropoda (insects, jointed legs), Mollusca (octopus, soft body) and Echinodermata (starfish, spiny skin and tube feet).Why is a whale a mammal and not a fish?
A whale breathes air with lungs, is warm-blooded, has some hair, gives birth to live young and feeds them milk from mammary glands. Fish breathe with gills, are cold-blooded and have scales. Living in water does not make an animal a fish.Which vertebrate classes are warm-blooded?
Only birds (Aves) and mammals (Mammalia) keep a constant body temperature. Fish, amphibians and reptiles are cold-blooded, their temperature changing with the surroundings. Birds and mammals also have four-chambered hearts.Where is animal classification covered in ICSE Class 9?
Diversity in the Animal Kingdom is Chapter 20 of ICSE Class 9 Biology, for the 2028 syllabus. Health Organisations (Chapter 18) is the previous chapter with an important-questions page here.How do I identify a specimen's phylum in the practical?
Look for one key feature: pores (Porifera), tentacles (Coelenterata), flat or round unsegmented body (Platyhelminthes, Nemathelminthes), ring segments (Annelida), jointed legs (Arthropoda), shell or soft body (Mollusca), or spiny skin with five arms (Echinodermata).Can I download Diversity in the Animal Kingdom ICSE questions?
Yes. Enter your email in the free PDF box on this page to open all 15 animal-classification questions with answers as a printable worksheet. It includes the specimen-identification questions.
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