Science & Technology · Chapter 02

61 solved questions

Chapter 2: Classification of Living Beings

Every question in this chapter, answered and explained — step-by-step solutions drawn live from the chapter library across 7 question sections.

Very Short Answer Questions17 Short Answer Questions18 Give Reason Questions8 Differentiate Between7 Long Answer Questions3 Diagram-Based Questions3 Application / Conceptual Questions5

Very Short Answer Questions

1SEE Boardqb-q0

Who classified organisms into five kingdoms?

Ans.Robert Harding Whittaker classified organisms into five kingdoms.

2SEE Boardqb-q1

Name the five kingdoms of classification.

Ans.Monera, Protista, Fungi, Plantae and Animalia.

3SEE Boardqb-q2

What is a thallus?

Ans.A plant body in which root, stem and leaf are not differentiated.

4SEE Boardqb-q3

Name the three divisions of kingdom Plantae.

Ans.Algae, Bryophyta and Tracheophyta.

5SEE Boardqb-q4

Why are bryophytes called amphibian plants?

Ans.Because they need water for fertilization, like amphibians need water/land both.

6SEE Boardqb-q5

Name the three sub-divisions of Tracheophyta.

Ans.Pteridophyta, Gymnosperm and Angiosperm.

7SEE Boardqb-q6

What are sori?

Ans.Brown spots found on the lower surface of fern leaves that contain sporangia.

8SEE Boardqb-q7

Name the two classes of angiosperms.

Ans.Monocotyledon and Dicotyledon.

9SEE Boardqb-q8

How many phyla are there in kingdom Animalia?

Ans.Nine phyla (eight invertebrate phyla and phylum Chordata).

10SEE Boardqb-q9

What is coelenteron?

Ans.A hollow, gastrovascular cavity found in coelenterates that performs digestion and transportation.

11SEE Boardqb-q10

Which is the largest phylum of the animal kingdom?

Ans.Arthropoda is the largest phylum of the animal kingdom.

12SEE Boardqb-q11

What is a notochord?

Ans.A developed, elastic, rod-like structure found between the nerve cord and alimentary canal in chordates.

13SEE Boardqb-q12

Name the four sub-phyla of Chordata.

Ans.Hemichordata, Urochordata, Cephalochordata and Vertebrata.

14SEE Boardqb-q13

Name the five classes of sub-phylum Vertebrata.

Ans.Pisces, Amphibia, Reptilia, Aves and Mammalia.

15SEE Boardqb-q14

How many chambers does the heart of a fish have?

Ans.Two chambers.

16SEE Boardqb-q15

How many chambers does the heart of a crocodile have?

Ans.Four chambers.

17SEE Boardqb-q16

What is meant by poikilothermic animals?

Ans.Animals whose body temperature changes according to the surrounding environment.

Short Answer Questions

1SEE Boardqb-q17

What is the basis of the five kingdom classification?

Ans.Whittaker classified organisms into five kingdoms on the basis of cell structure (prokaryotic/eukaryotic), body structure, mode of nutrition, and presence or absence of cell wall.

2SEE Boardqb-q18

Write the main characteristics of kingdom Plantae.

Ans.Plants have a cellulose cell wall, contain chlorophyll and are autotrophic. They may be unicellular or multicellular, and some bear flowers while others do not.

3SEE Boardqb-q19

What are the main characteristics of division Algae?

Ans.Algae have a thallus body (root, stem, leaf not differentiated), are autotrophic with a cellulose cell wall, reproduce both sexually and asexually, and are mostly found in water.

4SEE Boardqb-q20

Explain alternation of generation in bryophytes.

Ans.In bryophytes, the gametophyte generation produces male and female gametes that fuse to form a zygote; the zygote develops into a sporophyte that produces spores by meiosis. Gametophyte and sporophyte generations alternate to complete the life cycle, with the gametophyte generation being dominant.

5SEE Boardqb-q21

Write the main characteristics of Pteridophyta.

Ans.Pteridophytes are seedless plants found in moist, shady places. Their body is differentiated into root, underdeveloped stem (rhizome) and feather-like leaf, with developed vascular tissue. Sori on the lower leaf surface contain sporangia producing spores; spores germinate into a prothallus (gametophyte).

6SEE Boardqb-q22

Why are gymnosperms called naked-seeded plants?

Ans.Gymnosperms bear cones instead of flowers, and since there is no ovary in the cone, no fruit is formed. As a result, their seeds are not enclosed by any fruit wall, so they are called naked-seeded plants.

7SEE Boardqb-q23

What are the main characteristics of angiosperms?

Ans.Angiosperms are the most advanced plants of kingdom Plantae with well-developed root, stem, leaf, flower and fruit. They bear real flowers containing ovary and ovule, and their seeds are enclosed inside a fruit.

8SEE Boardqb-q24

Write the characteristics of phylum Porifera.

Ans.Poriferans are the first multicellular organisms, mostly asymmetrical, with pores (ostia and osculum) forming a water canal system. They respire through the body surface, show high regeneration capacity, and reproduce both sexually and asexually.

9SEE Boardqb-q25

Write the characteristics of phylum Coelenterata.

Ans.Coelenterates are diploblastic, radially symmetrical animals with a single body opening (mouth) surrounded by tentacles bearing stinging cells. They have a gastrovascular cavity (coelenteron) for digestion and transportation.

10SEE Boardqb-q26

Why are animals of phylum Platyhelminthes called flatworms?

Ans.Because their body is flat, leaf-like or long ribbon-like in shape ('platy' means flat and 'helminthes' means worms).

11SEE Boardqb-q27

Write the main features of phylum Arthropoda.

Ans.Arthropods have a hard chitinous exoskeleton, jointed legs, and a body divided into head, thorax and abdomen. They are bilaterally symmetrical, triploblastic and segmented, and are found in all types of habitats.

12SEE Boardqb-q28

Write the characteristics of phylum Mollusca.

Ans.Molluscs are soft-bodied animals with a body divided into head, visceral mass, muscular feet and mantle. Most have a calcium exoskeleton (shell), tentacles and eyes on the head, and well-developed digestive, circulatory and nervous systems.

13SEE Boardqb-q29

What are the characteristics of phylum Echinodermata?

Ans.Echinoderms have a hard calcareous spiny covering, radially symmetrical and triploblastic bodies, no distinct head, move using tube feet, and are found only in marine water.

14SEE Boardqb-q30

Write the main characteristics of phylum Chordata.

Ans.Chordates possess a developed, elastic, rod-like notochord between the nerve cord and alimentary canal at some stage of life, paired lateral gill openings in the embryonic stage, a hollow tubular nervous tissue, and a closed circulatory system.

15SEE Boardqb-q31

Write the characteristics of class Pisces.

Ans.Fish have an elongated, streamlined, scale-covered body with gills for respiration, fins for locomotion, a two-chambered heart, and are poikilothermic and mostly oviparous.

16SEE Boardqb-q32

Write the characteristics of class Amphibia.

Ans.Amphibians have moist skin, two pairs of limbs, and a three-chambered heart. They are poikilothermic; their young ones (tadpoles) respire through gills while adults use lungs and moist skin, and they need water for reproduction.

17SEE Boardqb-q33

Write the characteristics of class Aves.

Ans.Birds have a feather-covered body, forelimbs modified into wings, hollow pneumatic bones, a four-chambered heart, and are homeothermic, oviparous animals with air sacs in their bodies.

18SEE Boardqb-q34

Write the characteristics of class Mammalia.

Ans.Mammals have a hair-covered body, developed mammary glands, a four-chambered heart, and are homeothermic. They are unisexual with internal fertilization and are mostly viviparous.

Give Reason Questions

1SEE Boardqb-q35

Living beings need to be classified.

Ans.There are millions of organisms with wide variation in structure and function. Classification groups organisms with similar characteristics together, which makes it easier to study, identify, name and understand the relationships and evolutionary history of living beings.

2SEE Boardqb-q36

Fucus and Marchantia look alike, but Fucus is classified as algae while Marchantia is classified as bryophyta.

Ans.Although both have a thallus-like body, Fucus is found in water, lacks well-developed sex organs and vascular tissue like a typical alga, while Marchantia is found on moist land, produces gametes in antheridium/archegonium and shows a clear alternation of generation, which are bryophyte characteristics.

3SEE Boardqb-q37

Gymnosperms do not bear fruit.

Ans.In gymnosperms, there is no ovary inside the cone. Since fruit develops from a fertilized ovary, and gymnosperms lack an ovary, their seeds remain naked without being enclosed by any fruit.

4SEE Boardqb-q38

Although a crocodile has a four-chambered heart, it belongs to the reptilian class.

Ans.Classification is based on the overall set of characteristics, not a single feature. A crocodile has dry, horny scales, two pairs of limbs used for crawling, is poikilothermic and lays eggs like other reptiles - these features place it in class Reptilia despite its four-chambered heart.

5SEE Boardqb-q39

Although bats and whales have dissimilar characteristics, they belong to the same class.

Ans.Both bats and whales have a body covered with hair, developed mammary glands, a four-chambered heart, are homeothermic, and give birth directly to young ones which they feed with milk - these shared mammalian features place them in class Mammalia despite their different habitats and body forms.

6SEE Boardqb-q40

Riccia is an amphibian plant.

Ans.Riccia needs water for the male gamete to swim from the antheridium to the archegonium for fertilization, similar to how amphibian animals need both land and water; hence it is called an amphibian plant.

7SEE Boardqb-q41

Fern, Cycas and banana are kept in the same division (Tracheophyta) despite differences in their reproductive structures.

Ans.All three have a body differentiated into root, stem and leaf with developed vascular tissue (xylem and phloem) for transportation of substances, which is the main basis for placing them under division Tracheophyta, regardless of whether they reproduce by spores, naked seeds, or seeds inside fruit.

8SEE Boardqb-q42

Sponges (Porifera) can regenerate a new individual from a broken piece.

Ans.Sponges lack well-developed tissues and organs and have a high regeneration capacity; each piece of the body contains cells capable of dividing and reorganizing into a complete new individual.

Differentiate Between

1SEE Boardqb-q43

Differentiate: Plant Kingdom and Animal Kingdom

Plant Kingdom	Animal Kingdom
Have a cellulose cell wall.	No cell wall in cells.
Mostly autotrophic (prepare own food).	Heterotrophic (depend on other organisms for food).

2SEE Boardqb-q44

Differentiate: Fish and Starfish

Fish	Starfish
Belongs to phylum Chordata (vertebrate).	Belongs to phylum Echinodermata (invertebrate).
Body streamlined with fins; bilaterally symmetrical.	Body star-shaped with spines; radially symmetrical.

3SEE Boardqb-q45

Differentiate: Jellyfish and Cuttlefish

Jellyfish	Cuttlefish
Belongs to phylum Coelenterata.	Belongs to phylum Mollusca.
Radially symmetrical, has tentacles with nematocysts.	Asymmetrical body, has tentacles used mainly as sense organs and muscular feet for movement.

4SEE Boardqb-q46

Differentiate: Moss and Club Moss

Moss	Club Moss
Belongs to division Bryophyta.	Belongs to sub-division Pteridophyta (division Tracheophyta).
No true vascular tissue; grows only a few centimetres tall.	Has developed xylem and phloem; sporophyte generation is dominant.

5SEE Boardqb-q47

Differentiate: Pinus and Peepal

Pinus	Peepal
Gymnosperm; bears cones, naked seed, no fruit.	Angiosperm; bears real flowers, seed enclosed in fruit.
Needle-like leaves.	Broad leaves.

6SEE Boardqb-q48

Differentiate: Fish and Whale

Fish	Whale
Belongs to class Pisces; gills for respiration; poikilothermic.	Belongs to class Mammalia; lungs for respiration; homeothermic.
Two-chambered heart; mostly oviparous.	Four-chambered heart; viviparous, suckles milk to young.

7SEE Boardqb-q49

Differentiate: Dove and Bat

Dove	Bat
Belongs to class Aves; body covered with feathers.	Belongs to class Mammalia; body covered with hair.
Oviparous.	Viviparous, suckles milk to young ones.

Long Answer Questions

1SEE Boardqb-q50

Describe the classification of division Tracheophyta with examples.

Ans.Tracheophyta includes plants with a body differentiated into root, stem and leaf, and having xylem and phloem as vascular tissue. It is classified into three sub-divisions: (1) Pteridophyta - seedless plants with rhizome-like stems, feather-like leaves, and sori containing sporangia that produce spores; sporophyte generation is dominant (e.g., fern, horsetail, clubmoss). (2) Gymnosperm - plants bearing cones instead of flowers, with naked seeds and no fruit, needle-like leaves, and wind pollination (e.g., Pinus, Cycas, Juniper). (3) Angiosperm - the most advanced plants bearing real flowers with ovary and ovule, and seeds enclosed inside fruit; further divided into Monocotyledon (one cotyledon, parallel venation, fibrous root, e.g., maize) and Dicotyledon (two cotyledons, reticulate venation, taproot, e.g., pea).

2SEE Boardqb-q51

Describe the classes of sub-phylum Vertebrata with their main characteristics.

Ans.Sub-phylum Vertebrata is divided into five classes based on structure and development: (1) Pisces - aquatic, scale-covered, gill-breathing, two-chambered heart, poikilothermic, mostly oviparous (e.g., fish, shark). (2) Amphibia - moist skin, gill-breathing young and lung/skin-breathing adults, three-chambered heart, poikilothermic, need water for reproduction (e.g., frog, toad). (3) Reptilia - dry scaly skin, lung-breathing, three-chambered heart (four in crocodile), poikilothermic, oviparous (e.g., snake, lizard, crocodile). (4) Aves - feather-covered, wings, hollow bones, four-chambered heart, homeothermic, oviparous (e.g., pigeon, hen). (5) Mammalia - hair-covered, mammary glands, four-chambered heart, homeothermic, mostly viviparous (e.g., human, whale, bat).

3SEE Boardqb-q52

Explain the relationship between classification of living beings and evolution.

Ans.Classification groups organisms according to their similarities and differences, while evolution is the gradual change of living beings from simpler to more complex forms over time. When we compare organisms across kingdoms and phyla, those with more common features are found to share a more recent common ancestor, while those with fewer common features diverged from their common ancestor much earlier. For example, among vertebrates, Pisces has a two-chambered heart, Reptilia a three-chambered heart, while Aves and Mammalia both have a four-chambered heart, showing a gradual increase in complexity. Aves and Mammalia share more features with each other than with Pisces, indicating they evolved from a common ancestor more recently than Pisces did. This shows that classification of living beings reflects the pattern of their evolutionary history.

Diagram-Based Questions

1SEE Boardqb-q53

Draw and label a chart showing the five kingdom classification system.

Ans.Draw a flow chart starting from 'Organism' branching into Prokaryotes and Eukaryotes. Prokaryotes (unicellular) lead to Monera. Eukaryotes branch into unicellular (Protista) and multicellular. Multicellular further branches by cell wall presence: with cell wall (heterotrophic nutrition = Fungi, autotrophic nutrition = Plantae) and without cell wall (Animalia).

2SEE Boardqb-q54

Draw a chart to show classification of kingdom Plantae according to the five kingdom system.

Ans.Draw 'Plantae' branching into three divisions - Algae, Bryophyta and Tracheophyta. Show Tracheophyta further branching into Pteridophyta, Gymnosperm and Angiosperm, with Angiosperm branching into Monocotyledon and Dicotyledon. Label one example under each group (e.g., Algae - Spirogyra, Bryophyta - Moss, Pteridophyta - Fern, Gymnosperm - Pinus, Monocotyledon - Maize, Dicotyledon - Pea).

3SEE Boardqb-q55

Draw a chart to show classification of kingdom Animalia according to the five kingdom system.

Ans.Draw 'Animalia' branching into Invertebrates (without vertebral column) and Vertebrates (Chordata, with vertebral column). Under invertebrates, list the eight phyla: Porifera, Coelenterata, Platyhelminthes, Nemathelminthes, Annelida, Arthropoda, Mollusca, Echinodermata. Under Chordata/Vertebrata, list the five classes: Pisces, Amphibia, Reptilia, Aves, Mammalia, with one example under each.

Application / Conceptual Questions

1SEE Boardqb-q56

Two animals - a tapeworm and a frog - belong to the same kingdom. Look at their features and write the main reason for grouping them under the same kingdom.

Ans.Both are multicellular, eukaryotic organisms without a cell wall, and both are heterotrophs that depend on other organisms for food. These shared basic features place them together in kingdom Animalia, even though a tapeworm is an invertebrate parasite and a frog is a vertebrate.

2SEE Boardqb-q57

Digestive system is not developed in animals of phylum Porifera. How do they digest food?

Ans.Poriferans do not have a well-developed digestive system with organs. Instead, water carrying food particles enters the body through the ostia; specialized cells lining the water canals capture and digest the food particles intracellularly (inside individual cells), and the wastes are expelled through the osculum along with the water current.

3SEE Boardqb-q58

Rakesh saw an unknown animal while playing on the ground. How can he identify its phylum using taxonomic knowledge of kingdom Animalia?

Ans.Rakesh can observe the animal's features step by step: whether it has a vertebral column (to decide vertebrate or invertebrate), the type of body covering (exoskeleton, scales, shell, spines, or soft body), body symmetry (radial or bilateral), presence of segmentation or jointed legs, and habitat. By comparing these observed features with the characteristics of each phylum discussed in the chapter, he can determine which phylum the animal most likely belongs to.

4SEE Boardqb-q59

Shark and whale both live in water. Based on their features, which is a more developed animal? Explain with reasons.

Ans.The whale is a more developed (advanced) animal. A shark is a fish (class Pisces) that breathes through gills, is poikilothermic, has a two-chambered heart, and is mostly oviparous. A whale is a mammal (class Mammalia) that breathes through lungs, is homeothermic, has a four-chambered heart, and is viviparous, giving birth to young ones and feeding them milk from mammary glands. These features show that the whale has a more advanced level of organization, even though it lives in water like a fish.

5SEE Boardqb-q60

Roshni observed only the flowers of a new plant in her garden and concluded that the plant belongs to monocotyledon. Is observation of only the flowers a right way to identify monocotyledon? Give reasons.

Ans.Observing only the flower is not sufficient by itself, although floral parts in multiples of three is one useful clue for monocotyledons. A more reliable identification requires checking multiple features together: type of leaf venation (parallel for monocot, reticulate for dicot), type of root system (fibrous for monocot, taproot for dicot), and the number of cotyledons in the seed. Using several characteristics together gives a more accurate and dependable identification than relying on the flower alone.

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