CBSE Class 9 Science Diversity in Organisms Sure Shot Questions Set 03

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1. Find out incorrect sentence [1 Mark]
(A) Protista includes unicellular eukaryotic organisms
(B) Whittaker considered cell structure, mode and source of nutrition for classifying the organisms in five kingdoms
(C) Both Monera and Protista may be autotrophic and heterotrophic
(D) Monerans have well defined nucleus

Answer: (D) Monerans have well defined nucleus

1. Monerans are prokaryotic organisms which lack a well-defined nucleus and membrane-bound organelles.
2. Protista consists of unicellular eukaryotes, making statement (A) correct.
3. Whittaker used cell structure, thallus organization, mode of nutrition, and phylogenetic relationships, making (B) correct.
4. Hence, the incorrect statement is (D).

Teacher's Note:
a) Prokaryotes do not possess a true nuclear membrane.
b) Read all options carefully before selecting the false statement.

2. Which among the following has specialised tissue for conduction of water? [1 Mark]
(i) Thallophyta
(ii) Bryophyta
(iii) Pteridophyta
(iv) Gymnosperms
(A) (i) and (ii)
(B) (ii) and (iii)
(C) (iii) and (iv)
(D) (i) and (iv)

Answer: (C) (iii) and (iv)

1. Vascular tissues xylem and phloem for conduction appear first in Pteridophyta.
2. Gymnosperms and Angiosperms also possess well-developed vascular tissues.
3. Thallophytes and Bryophytes lack specialized vascular tissues.
4. Hence, the correct combination is (iii) and (iv), which corresponds to option (C).

Teacher's Note:
a) Pteridophytes are the first vascular cryptogams.
b) Thallophytes and bryophytes rely on diffusion for transport.

3. Which among the following produce seeds? [1 Mark]
(A) Thallophyta
(B) Bryophyta
(C) Pteridophyta
(D) Gymnosperms

Answer: (D) Gymnosperms

1. Gymnosperms and angiosperms are phanerogams, meaning they bear seeds.
2. Thallophytes, bryophytes, and pteridophytes are cryptogams, meaning they produce naked embryos called spores without seeds.
3. Gymnosperms bear naked seeds not enclosed inside a fruit.
4. Hence, the correct option is (D).

Teacher's Note:
a) Phanerogams are seed-bearing plants.
b) Cryptogams reproduce via spores.

4. Which one is a true fish? [1 Mark]
(A) Jellyfish
(B) Starfish
(C) Dogfish
(D) Silverfish

Answer: (C) Dogfish

1. Dogfish (Scoliodon) belongs to class Chondrichthyes under vertebrates, making it a true fish.
2. Jellyfish is a coelenterate.
3. Starfish is an echinoderm.
4. Silverfish is an insect (arthropod).

Teacher's Note:
a) Many common names include the word fish incorrectly.
b) True fishes possess gills, fins, and a vertebrate column.

5. Which among the following is exclusively marine? [1 Mark]
(A) Porifera
(B) Echinodermata
(C) Mollusca
(D) Pisces

Answer: (B) Echinodermata

1. All members of phylum Echinodermata are exclusively marine living in the sea.
2. Porifera, Mollusca, and Pisces have many freshwater representatives.
3. Echinoderms lack freshwater or terrestrial adaptations.
4. Hence, the correct option is (B).

Teacher's Note:
a) Echinoderms possess a unique water vascular system.
b) Phylum Echinodermata includes starfish and sea urchins.

6. Which among the following have open circulatory system? [1 Mark]
(i) Arthropoda
(ii) Mollusca
(iii) Annelida
(iv) Coelenterata
(A) (i) and (ii)
(B) (iii) and (iv)
(C) (i) and (iii)
(D) (ii) and (iv)

Answer: (A) (i) and (ii)

1. Arthropods and most molluscs have an open circulatory system where blood flows in open spaces called sinuses.
2. Annelids possess a closed circulatory system.
3. Coelenterates lack a distinct circulatory system entirely, utilizing gastrovascular cavities.
4. Hence, the correct combination is (i) and (ii), matching option (A).

Teacher's Note:
a) Open circulatory systems have blood bathing tissues directly.
b) Cephalopod molluscs are an exception with a closed system.

7. In which group of animals, coelom is filled with blood? [1 Mark]
(a) Arthropoda
(b) Annelida
(c) Nematoda
(d) Echinodermata

Answer: (a) Arthropoda

1. Arthropods possess an open circulatory system where the blood-filled cavity is termed haemocoel.
2. The true coelom is reduced and filled with blood.
3. Hence, the correct option is (a).

Teacher's Note:
a) Arthropoda is characterised by an open circulatory system.
b) Recall that coelom is reduced to haemocoel in this phylum.

8. Elephantiasis is caused by [1 Mark]
(a) Wuchereria
(b) Pinworm
(c) Planarians
(d) Liver flukes

Answer: (a) Wuchereria

1. Elephantiasis is caused by filarial worms belonging to the genus Wuchereria.
2. They block lymphatic vessels leading to severe swelling.
3. Hence, the correct option is (a).

Teacher's Note:
a) Wuchereria bancrofti is a parasitic nematode.
b) Note the vector-borne transmission through mosquitoes.

9. Which one is the most striking or (common) character of the vertebrates? [1 Mark]
(a) Presence of notochord
(b) Presence of triploblastic condition
(c) Presence of gill pouches
(d) Presence of coelom

Answer: (a) Presence of notochord

1. Vertebrates are a subphylum of Chordata defined by the presence of a vertebral column and notochord at some stage.
2. Notochord is the fundamental diagnostic feature of chordates and vertebrates.
3. Hence, the correct option is (a).

Teacher's Note:
a) All vertebrates are chordates, possessing a notochord.
b) Other options like coelom are shared with non-vertebrate groups.

10. Which among the following have scales? [1 Mark]
(i) Amphibians
(ii) Pisces
(iii) Reptiles
(iv) Mammals
(a) (i) and (iii)
(b) (iii) and (iv)
(c) (ii) and (iii)
(d) (i) and (ii)

Answer: (c) (ii) and (iii)

1. Pisces (fishes) possess scales covering their skin for protection and locomotion.
2. Reptiles have epidermal scales or scutes.
3. Amphibians have moist, glandular skin without scales, while mammals possess hair or fur.
4. Hence, the correct option is (c).

Teacher's Note:
a) Pisces and reptiles both possess external scales.
b) Amphibians lack scales entirely to aid in cutaneous respiration.

11. Find out the false statement [1 Mark]
(a) Aves are warm blooded, egg laying and have four chambered heart
(b) Aves have feather covered body, fore limbs are modified as wing and breathe through lungs
(c) Most of the mammals are viviparous
(d) Fishes, amphibians and reptiles are oviparous

Answer: (d) Fishes, amphibians and reptiles are oviparous (the marking scheme also accepts option (d) as generally considered broadly true, but note that some reptiles and certain fish/amphibians are viviparous or ovoviviparous, though option (d) is intended as the textbook standard answer in typical multiple choice questions).

1. Statements (a), (b), and (c) state established biological facts about Aves and mammals.
2. While most fishes, amphibians, and reptiles lay eggs, certain species show viviparity or ovoviviparity, making absolute generalisation tricky, but in the context of class 9 diversity, this is marked as the exception or textbook false statement compared to others.
3. Hence, the correct option is (d).

Teacher's Note:
a) Read each statement carefully against general vertebrate characteristics.
b) Watch out for exceptions in reproductive modes across animal groups.

12. Pteridophyta do not have [1 Mark]
(a) root
(b) stem
(c) flowers
(d) leaves

Answer: (c) flowers

1. Pteridophytes are cryptogams, meaning they do not produce flowers, fruits, or seeds.
2. They possess well-differentiated roots, stems, and leaves along with vascular tissue.
3. Hence, the correct option is (c).

Teacher's Note:
a) Cryptogams lack flowers and seeds, unlike phanerogams.
b) Remember that pteridophytes do have true roots, stems, and leaves.

13. Identify a member of porifera [1 Mark]
(a) Spongilla
(b) Euglena
(c) Penicillium
(d) Hydra

Answer: (a) Spongilla

1. Spongilla is a freshwater sponge belonging to the phylum Porifera.
2. Euglena is a protozoan protist, Penicillium is a fungus, and Hydra belongs to Cnidaria.
3. Hence, the correct option is (a).

Teacher's Note:
a) Sponges are pore-bearing multicellular animals of Porifera.
b) Always distinguish animal phyla from fungi and protists.

14. Which is not an aquatic animal? [1 Mark]
(a) Hydra
(b) Jelly fish
(c) Corals
(d) Filaria

Answer: (d) Filaria

1. Hydra, jelly fish, and corals are aquatic invertebrates found in water habitats.
2. Filaria (Wuchereria bancrofti) is a parasitic roundworm that lives inside human lymphatic vessels.
3. Hence, filaria is not an aquatic animal, and the correct option is (d).

Teacher's Note:
a) Filarial worm is an endoparasite causing filariasis in humans.
b) Pay close attention to parasitic versus free-living habits in classification.

15. Amphibians do not have the following [1 Mark]
(a) Three chambered heart
(b) Gills or lungs
(c) Scales
(d) Mucus glands

Answer: (c) Scales

1. Amphibians possess a three-chambered heart and respire through gills, lungs, or skin.
2. Their skin is moist and contains mucus glands.
3. Scales are absent in amphibians, unlike reptiles and fishes. Hence, the correct option is (c).

Teacher's Note:
a) Amphibian skin lacks external scales and is kept moist by mucus secretions.
b) Distinguish vertebrate classes by external body covering features.

16. Organisms without nucleus and cell organelles belong to [1 Mark]
(i) fungi
(ii) protista
(iii) cyano bacteria
(iv) archae bacteria
(a) (i) and (ii)
(b) (iii) and (iv)
(c) (i) and (iv)
(d) (ii) and (iii)

Answer: (b) (iii) and (iv)

1. Organisms without a defined nucleus and membrane-bound cell organelles are prokaryotes.
2. Fungi and protists are eukaryotes with a distinct nucleus and cell organelles.
3. Cyanobacteria and archaebacteria are prokaryotic microorganisms. Hence, the correct option is (b).

Teacher's Note:
a) Prokaryotic cells lack a nuclear membrane and bound organelles.
b) Remember that Monera comprises all prokaryotes such as bacteria and cyanobacteria.

17. Which of the following is not a criterion for classification of living organisms? [1 Mark]
(a) Body design of the organism
(b) Ability to produce one’s own food
(c) Membrane bound nucleus and cell organelles
(d) Height of the plant

Answer: (d) Height of the plant

1. Fundamental characteristics used for classification include cell structure, mode of nutrition, and body organization.
2. Plant height is a variable morphological feature influenced by environment rather than a fundamental taxonomic criterion.
3. Hence, the correct option is (d).

Teacher's Note:
a) Taxonomic criteria rely on stable, fundamental evolutionary traits.
b) Avoid confusing superficial variations like size with genetic classification traits.

18. The feature that is not a characteristic of protochordata? [1 Mark]
(a) Presence of notochord
(b) Bilateral symmetry and coelom
(c) Jointed legs
(d) Presence of circulatory system

Answer: (c) Jointed legs

1. Protochordates possess a notochord at some stage of life, bilateral symmetry, and a coelom.
2. They also exhibit a circulatory system.
3. Jointed legs are the characteristic feature of phylum Arthropoda, not protochordata. Hence, the correct option is (c).

Teacher's Note:
a) Jointed appendages define arthropods, the largest animal phylum.
b) Protochordates are exclusively marine animals showing chordate affinities.

19. The locomotory organs of Echinodermata are [1 Mark]
(a) tube feet      (b) muscular feet
(c) jointed legs      (d) parapodia

Answer: (a) tube feet

1. Echinoderms possess a unique water-vascular system.
2. Tube feet are hydraulic structures operated by this system used for locomotion, respiration, and food capture.
3. Hence, the correct option is (a).

Teacher's Note:
a) Water vascular system is a defining diagnostic feature of echinoderms.
b) Parapodia are found in annelids like Nereis.

20. Corals are [1 Mark]
(a) Poriferans attached to some solid support
(b) Cnidarians, that are solitary living
(c) Poriferans present at the sea bed
(d) Cnidarians that live in colonies

Answer: (d) Cnidarians that live in colonies

1. Corals belong to the phylum Cnidaria (Coelenterata).
2. They secrete hard calcium carbonate skeletons and typically live in large interconnected colonies.
3. Hence, the correct option is (d).

Teacher's Note:
a) Coral reefs are formed by the skeletal deposits of colonial cnidarians.
b) Poriferans are sponges, which differ structurally from cnidarians.

21. Who introduced the system of scientific nomenclature of organisms [1 Mark]
(A) Robert Whittaker
(B) Carolus Linnaeus
(C) Robert Hooke
(D) Ernst Haeckel

Answer: (B) Carolus Linnaeus

1. Carolus Linnaeus introduced the binomial nomenclature system for naming organisms.
2. This system uses a two-part naming method consisting of genus and species names.
3. Hence, the correct option is (B).

Teacher's Note:
a) Binomial nomenclature standardizes biological names globally.
b) Robert Whittaker proposed the five-kingdom classification system.

22. Two chambered heart occurs in [1 Mark]
(A) crocodiles
(B) fish
(C) aves
(D) amphibians

Answer: (B) fish

1. Fishes possess a simple two-chambered heart consisting of an atrium and a ventricle.
2. Deoxygenated blood is pumped to the gills for oxygenation in a single circulation loop.
3. Hence, the correct option is (B).

Teacher's Note:
a) Amphibians and most reptiles have a three-chambered heart.
b) Birds and mammals possess an advanced four-chambered heart.

23. Skeleton is made entirely of cartilage in [1 Mark]
(A) Sharks
(B) Tuna
(C) Rohu
(D) None of these

Answer: (A) Sharks

1. Sharks belong to Chondrichthyes, which are cartilaginous fishes.
2. Tuna and Rohu are bony fishes belonging to Osteichthyes with a bony skeleton.
3. Hence, the correct option is (A).

Teacher's Note:
a) Cartilaginous fish lack true bone tissue entirely.
b) Remember that rays and skates are also cartilaginous fishes.

24. One of the following is not an Annelid [1 Mark]
(A) Nereis
(B) Earthworm
(C) Leeches
(D) Urchins

Answer: (D) Urchins

1. Sea urchins belong to the phylum Echinodermata, not Annelida.
2. Nereis, earthworms, and leeches are segmented worms belonging to phylum Annelida.
3. Hence, the correct option is (D).

Teacher's Note:
a) Annelids are characterized by metameric segmentation and a coelom.
b) Echinoderms are spiny-skinned marine invertebrate animals.

25. The book Systema Naturae was written by [1 Mark]
(A) Linnaeus
(B) Haeckel
(C) Whittaker
(D) Robert Brown

Answer: (A) Linnaeus

1. Systema Naturae is a foundational work written by Carolus Linnaeus.
2. It outlines his system for classifying plants and animals.
3. Hence, the correct option is (A).

Teacher's Note:
a) This publication established binomial nomenclature as standard practice in botany and zoology.
b) Note the spelling and historical significance of the text.

26. Karl Von Linne was involved with which branch of science? [1 Mark]
(A) Morphology
(B) Taxonomy
(C) Physiology
(D) Medicine

Answer: (B) Taxonomy

Karl Von Linne, also known as Carolus Linnaeus, is widely regarded as the father of modern taxonomy. 1. Taxonomy is the science of naming, describing, and classifying organisms.
2. Hence, the correct option is (B).

Teacher's Note:
a) Taxonomy provides hierarchical categories like kingdom, phylum, and class.
b) Morphology studies form and structure rather than classification systems.

27. Real organs are absent in [1 Mark]
(A) Mollusca
(B) Coelenterata
(C) Arthropoda
(D) Echinodermata

Answer: (B) Coelenterata

1. Coelenterates (Cnidarians) exhibit tissue-level organization without true organ systems.
2. Molluscs, arthropods, and echinoderms possess well-developed organ systems.
3. Hence, the correct option is (B).

Teacher's Note:
a) Tissue level means cells performing similar functions are grouped into tissues.
b) Porifera exhibits cellular level, while Coelenterata exhibits tissue level.

28. Hard calcium carbonate structures are used as skeleton by [1 Mark]
(A) Echinodermata
(B) Protochordata
(C) Arthropoda
(D) Nematoda

Answer: (A) Echinodermata

1. Echinoderms possess a hard exoskeleton or endoskeleton made of calcium carbonate plates and spines.
2. Arthropods use chitinous exoskeletons instead.
3. Hence, the correct option is (A).

Teacher's Note:
a) Starfish and sea urchins are classic examples of echinoderms with calcareous structures.
b) Do not confuse the calcium carbonate skeleton of echinoderms with the chitinous exoskeleton of insects.

29. Differentiation in segmental fashion occurs in [1 Mark]
(A) Leech
(B) Starfish
(C) Snails
(D) Ascaris

Answer: (A) Leech

1. Leech belongs to phylum Annelida, which is characterized by metameric segmentation.
2. Starfish belongs to Echinodermata.
3. Snails belong to Mollusca.
4. Hence, the correct option is (A).

Teacher's Note:
a) Segmental segmentation means the body is divided into similar segments externally and internally.
b) Annelids show true metameric segmentation, which is absent in roundworms and molluscs.

30. In taxonomic hierarchy family comes between [1 Mark]
(A) Class and Order
(B) Order and Genus
(C) Genus and Species
(D) Division and Class

Answer: (B) Order and Genus

1. The hierarchical sequence of taxonomic categories is Kingdom, Phylum/Division, Class, Order, Family, Genus, Species.
2. Family is placed precisely between Order and Genus.
3. Hence, the correct option is (B).

Teacher's Note:
a) Memorize the ascending or descending order of taxonomic ranks to avoid confusion.
b) Genus comes immediately before species, and order comes immediately before family.

31. The 5-Kingdom classification has given by [1 Mark]
(A) Morgan
(B) R. Whittaker
(C) Linnaeus
(D) Haeckel

Answer: (B) R. Whittaker

1. Robert H. Whittaker proposed the famous five-kingdom classification in 1969.
2. The five kingdoms are Monera, Protista, Fungi, Plantae, and Animalia.
3. Hence, the correct option is (B).

Teacher's Note:
a) Classification is based on cell structure, mode of nutrition, and thallus organization.
b) Linnaeus proposed the two-kingdom system earlier.

32. Well defined nucleus is absent in [1 Mark]
(A) blue green algae
(B) diatoms
(C) algae
(D) yeast

Answer: (A) blue green algae

1. Blue green algae are cyanobacteria, which are prokaryotic organisms lacking a well-defined nucleus and membrane-bound organelles.
2. Diatoms, algae, and yeast are eukaryotes with a true, well-defined nucleus.
3. Hence, the correct option is (A).

Teacher's Note:
a) Prokaryotes lack a nuclear membrane, whereas eukaryotes possess a distinct nucleus.
b) Do not get confused by the word algae in blue green algae; they are actually bacteria (cyanobacteria).

33. The 'Origin of Species' is written by [1 Mark]
(A) Linnaeus
(B) Darwin
(C) Hackel
(D) Whittaker

Answer: (B) Darwin

1. The landmark book 'On the Origin of Species' was written by Charles Darwin in 1859.
2. It laid the foundation of evolutionary biology through natural selection.
3. Hence, the correct option is (B).

Teacher's Note:
a) Ernst Haeckel coined the term ecology and proposed three kingdoms.
b) Charles Darwin's evolutionary concepts link closely with biological classification and relationships.

34. Meena and Hari observed an animal in their garden. Hari called it an insect while Meena said it was an earthworm. Choose the character from the following which confirms that it is an insect. [1 Mark]
(A) Bilateral symmetrical body
(B) Body with jointed legs
(C) Cylindrical body
(D) Body with little segmentation

Answer: (B) Body with jointed legs

1. Insects belong to the phylum Arthropoda, which is characterized by jointed appendages.
2. Earthworms belong to Annelida, which lack jointed legs.
3. Hence, the correct option is (B).

Teacher's Note:
a) Arthropoda means jointed legs, the largest phylum in the animal kingdom.
b) Both insects and earthworms exhibit bilateral symmetry, so that cannot distinguish them.

35. Write true (T) or false (F) [6 Marks]
(a) Whittaker proposed five kingdom classification.
(b) Monera is divided into Archaebacteria and Eubacteria.
(c) Starting from Class, Species comes before the Genus.
(d) Anabaena belongs to the kingdom Monera.
(e) Blue green algae belongs to the kingdom Protista.
(f) All prokaryotes are classified under Monera.

Answer:
1. (a) True - R.H. Whittaker proposed the five-kingdom classification in 1969.
2. (b) True - Kingdom Monera includes diverse prokaryotes broadly grouped into Archaebacteria and Eubacteria.
3. (c) False - In taxonomic hierarchy, Genus comes before Species when moving from broad to specific (Kingdom, Phylum, Class, Order, Family, Genus, Species).
4. (d) True - Anabaena is a cyanobacterium, which is a prokaryote belonging to Monera.
5. (e) False - Blue green algae are prokaryotic cyanobacteria and belong to Monera, not Protista.
6. (f) True - All prokaryotic organisms are placed under the kingdom Monera.

Teacher's Note:
a) Statements test foundational knowledge of biological classification principles.
b) Pay close attention to taxonomic ranking order and prokaryotic versus eukaryotic kingdom assignments.

36. Fill in the blanks [7 Marks]
(a) Fungi shows ——— mode of nutrition.
(b) Cell wall of fungi is made up of ———.
(c) Association between blue green algae and fungi is called as ———.
(d) Chemical nature of chitin is ———.
(e) ——— has smallest number of organisms with maximum number of similar characters
(f) Plants without well differentiated stem, root and leaf are kept in ———.
(g) ——— are called as amphibians of the plant kingdom.

Answer:
1. (a) heterotrophic (saprophytic/parasitic)
2. (b) chitin
3. (c) lichen
4. (d) complex sugar (polysaccharide / N-acetylglucosamine polymer)
5. (e) Species
6. (f) Thallophyta
7. (g) Bryophytes

Teacher's Note:
a) Fungi lack chlorophyll and absorb nutrients from dead or living organic matter.
b) Chitin provides rigid structural support to fungal cell walls.
c) Lichens represent a classic mutualistic symbiotic association.
d) Species is the lowest taxonomic category sharing the maximum similarities.

37. You are provided with the seeds of gram, wheat, rice, pumpkin, maize and pea. Classify them whether they are monocot or dicot. [3 Marks]

Answer:
1. Monocot seeds: Wheat, Rice, Maize.
2. Dicot seeds: Gram, Pumpkin, Pea.
3. Classification is based on the presence of single cotyledon in monocots and two cotyledons in dicots.

Teacher's Note:
a) Monocots typically have parallel venation in leaves and fibrous root systems.
b) Dicots generally possess reticulate venation and a tap root system.
c) Cereals like wheat, rice and maize are monocotyledonous seeds.

38. Match items of column (A) with items of column (B) [7 Marks]

Answer:
1. (a) - (B)
2. (b) - (A)
3. (c) - (D)
4. (d) - (C)
5. (e) - (F)
6. (f) - (E)
7. (g) - (G)

Teacher's Note:
a) Gymnosperms bear unenclosed seeds whereas angiosperms have enclosed seeds within fruits.
b) Euglena is a unicellular protist moving via flagella.
c) Plant kingdom subdivisions range from thallophytes lacking differentiated plant bodies to seed plants.

39. Match items of column (A) with items of column (B) [6 Marks]

Answer:
1. (a) - (C)
2. (b) - (B)
3. (c) - (F)
4. (d) - (A)
5. (e) - (E)
6. (f) - (D)

Teacher's Note:
a) Porifera members possess a canal system with pores for water transport.
b) Arthropoda is the largest animal phylum characterized by jointed appendages.
c) Metameric segmentation implies body division into serial segments internally and externally.

40. Classify the following organisms based on the absence/presence of true coelom (i.e., acoelomate, pseudocoelomate and coelomate) Spongilla, Sea anemone, Planaria, Liver fluke Wuchereria, Ascaris, Nereis, Earthworm, Scorpion, Birds, Fishes, Horse. [4 Marks]

Answer:
1. Acoelomate organisms: Spongilla, Sea anemone, Planaria, Liver fluke.
2. Pseudocoelomate organisms: Wuchereria, Ascaris.
3. Coelomate organisms: Nereis, Earthworm, Scorpion, Birds, Fishes, Horse.
4. True coelom is a body cavity arising within the mesoderm.

Teacher's Note:
a) Acoelomates lack a body cavity between the body wall and digestive tract.
b) Pseudocoelomates possess a fluid-filled body cavity not lined entirely by mesoderm.
c) Coelomates have a true coelom lined by mesodermal epithelium on all sides.

41. Endoskeleton of fishes are made up of cartilage and bone; classify the following fishes as cartilagenous or bony Torpedo, Sting ray, Dog fish, Rohu, Angler fish, Exocoetus. [3 Marks]

Answer:
1. Cartilaginous fishes: Torpedo, Sting ray, Dog fish.
2. Bony fishes: Rohu, Angler fish, Exocoetus.
3. Cartilaginous fishes possess a skeleton made entirely of cartilage, whereas bony fishes have a hard bony endoskeleton.

Teacher's Note:
a) Chondrichthyes (cartilaginous fishes) have ventral mouths and placoid scales.
b) Osteichthyes (bony fishes) feature terminal mouths and operculum covering gills.
c) Torpedo and sting ray belong to cartilaginous marine fishes.

42. Classify the following based on number of chambers in their heart. Rohu, Scoliodon, Frog, Salamander, Flying lizard, King Cobra, Crocodile, Ostrich, Pigeon, Bat, Whale [4 Marks]

Answer:
1. Two-chambered heart: Rohu, Scoliodon.
2. Three-chambered heart: Frog, Salamander, Flying lizard, King Cobra.
3. Four-chambered heart (exceptions and standard): Crocodile (4-chambered), Ostrich, Pigeon, Bat, Whale.
4. Fishes have 2 chambers, amphibians and most reptiles have 3, and birds and mammals have 4 chambers.

Teacher's Note:
a) Crocodile is a unique reptile possessing a four-chambered heart.
b) Amphibians and reptiles generally exhibit mixing of oxygenated and deoxygenated blood due to incomplete partitioning.
c) Birds and mammals maintain complete separation of oxygenated and deoxygenated blood streams.

43. Classify Rohu, Scolidon, Flying lizard, King Kobra, Frog, Salamander, Ostrich, Pigeon, Bat, Crocodile and Whale into the cold blooded/warm blooded animals. [3 Marks]

Answer:
1. Cold-blooded (Poikilothermic) animals: Rohu, Scolidon, Flying lizard, King Kobra, Frog, Salamander, Crocodile.
2. Warm-blooded (Homeothermic) animals: Ostrich, Pigeon, Bat, Whale.
3. Cold-blooded animals cannot regulate their internal body temperature according to the environment, whereas warm-blooded animals maintain a constant body temperature.

Teacher's Note:
a) Pisces, amphibians and reptiles are poikilotherms.
b) Aves (birds) and mammals are homeotherms.
c) Crocodile is classified as cold-blooded despite having a four-chambered heart.

44. Name two egg laying mammals. [1 Mark]

Answer:
1. Platypus and Echidna (Spiny anteater) are egg-laying mammals (monotremes).

Teacher's Note:
a) Monotremes represent an exceptional primitive group of mammals that lay large yolky eggs rather than giving birth to live young.

45. Fill in the blanks [4 Marks]
(a) Five kingdom classification of living organisms is given by - - - .
(b) Basic smallest unit of classification is - - - .
(c) Prokaryotes are grouped in Kingdom - - - .
(d) Paramecium is a protista because of its - - - .
(e) Fungi do not contain - - - .
(f) A fungus - - - can be seen without microscope.
(g) Common fungi used in preparing the bread is - - - .
(h) Algae and fungi form symbiotic association called - - - .

Answer:
1. (a) Whittaker
2. (b) Species
3. (c) Monera
4. (d) unicellular eukaryotic structure
5. (e) chlorophyll
6. (f) Mushroom (Agaricus)
7. (g) Yeast
8. (h) Lichen

Teacher's Note:
a) R.H. Whittaker proposed the five-kingdom system.
b) Species is the lowest and most basic taxonomic rank.
c) Fungi are heterotrophic eukaryotic organisms lacking chlorophyll.

46. Give True (T) and False (F) [3 Marks]
(a) Gymnosperms differ from Angiosperms in having covered seed.
(b) Non flowering plants are called Cryptogamae.
(c) Bryophytes have conducting tissue.
(d) Funaria is a moss.
(e) Compound leaves are found in many ferns.
(f) Seeds contain embryo.

Answer:
1. (a) False (Gymnosperms have naked seeds, whereas Angiosperms have covered seeds).
2. (b) True
3. (c) False (Bryophytes lack specialized vascular tissues for conduction).
4. (d) True
5. (e) True
6. (f) True

Teacher's Note:
a) Cryptogams mean hidden reproductive organs.
b) Vascular tissues xylem and phloem are absent in bryophytes.
c) Read statements carefully regarding seed covering.

47. Give examples for the following [2 Marks]
(a) Bilateral, dorsiventral symmetry is found in - - - .
(b) Worms causing disease elephantiasis is - - - .
(c) Open circulatory system is found in - - - where coelomic cavity is filled with blood.
(d) - - - are known to have pseudocoelom.

Answer:
1. (a) Liver fluke (Platyhelminthes)
2. (b) Filarial worm (Wuchereria)
3. (c) Arthropods (or Molluscs, Haemocoel)
4. (d) Nematodes (Aschelminthes)

Teacher's Note:
a) Coelomic cavity filled with blood is called haemocoel.
b) Pseudocoelomates have false body cavities derived from the blastocoel.

48. Label a, b, c and d. given in below figure. Give the function of (b) [3 Marks]

Answer:
1. Label (a) is Dorsal fin, (b) is Caudal fin (tail fin), (c) is Anal fin, and (d) is Pelvic fin.
2. Function of label (b) (Caudal fin): It helps in propelling the fish forward and in steering and changing direction in water.
3. Fins help in steering and balancing the fish in water.

Teacher's Note:
a) Aquatic adaptations in fish include streamlined bodies and fins.
b) The lateral line system is crucial for orientation and predator detection.
c) Label clearly as requested in anatomical diagrams.

49. Write names of few thallophytes. Draw a labelled diagram of Spirogyra. [3 Marks]

Answer:
1. Examples of thallophytes include Spirogyra, Ulothrix, Cladophora, Ulva, and Chara.
2. Spirogyra is a filamentous green alga with ribbon-shaped spiral chloroplasts containing pyrenoids.
3. The labeled diagram shows cell wall, spiral chloroplast, pyrenoid, nucleus, and vacuole.

Teacher's Note:
a) Thallophyta plants do not have a well-differentiated body design.
b) Pyrenoids store starch in algal cells.
c) Drawing should clearly highlight the spiral chloroplast.

50. Thallophyta, bryophyta and pteridophyta are called as 'Cryptogams'. Gymnosperms and Angiosperms are called as 'phanerogams'. Discuss why? Draw one example of Gymnosperm. [4 Marks]

[Figure: Sketch of a pine branch or Pinus tree representing a Gymnosperm]

Answer:
1. Thallophyta, bryophyta, and pteridophyta are called 'Cryptogams' because they have inconspicuous, hidden reproductive organs and do not produce seeds.
2. Gymnosperms and Angiosperms are called 'Phanerogams' because they have well-differentiated reproductive tissues that produce seeds.
3. Cryptogams reproduce via spores, whereas phanerogams bear seeds containing embryos and stored food.
4. Pinus or Cycas is a typical example of a gymnosperm with naked seeds borne on sporophylls.

Teacher's Note:
a) Cryptogamae translates to hidden flowers.
b) Phanerogamae refers to visible reproductive structures.
c) Gymnosperms bear naked seeds not enclosed in fruit walls.
d) Clear separation is based on seed habit.

51. Define the terms and give one example of each (a) Bilateral symmetry (b) Coelom (c) Triploblastic [3 Marks]

Answer:
1. (a) Bilateral symmetry: Body can be divided into identical left and right halves in only one plane. Example: Humans or Insects.
2. (b) Coelom: A true body cavity arising inside the mesoderm. Example: Annelids or Arthropods.
3. (c) Triploblastic: Animals having three primary germ layers (ectoderm, mesoderm, and endoderm). Example: Flatworms to Chordates.

Teacher's Note:
a) Symmetry types reflect body organization complexity.
b) Coelom provides space for internal organs.
c) Triploblasty allows formation of complex organ systems.

52. You are given leech, Nereis, Scolopendra, prawn and scorpion; and all have segmented body organisation. Will you classify them in one group? If no, give the important characters based on which you will separate these organisms into different groups. [4 Marks]

Answer:
1. No, they cannot be classified into a single group despite having segmented bodies.
2. Leech and Nereis belong to Phylum Annelida, characterized by metamers separated by rings, soft bodies, and lack of jointed appendages.
3. Scolopendra, prawn, and scorpion belong to Phylum Arthropoda.
4. Arthropods are distinguished by jointed appendages, chitinous exoskeleton, and a haemocoel.

Teacher's Note:
a) Segmentation alone is not sufficient for classification.
b) Annelids possess coelom and setae/parapodia for locomotion.
c) Arthropods possess chitinous exoskeletons and jointed legs.
d) Taxonomic keys rely on multiple distinguishing morphological traits.

53. Fill in the boxes given in below figure with appropriate characteristics/plant group (s) [3 Marks]

Answer:
1. Box a: Thallophyta (Algae)
2. Box b: Without vascular tissue
3. Box c: Pteridophyta
4. Box d: Phanerogams (Seed-bearing plants)
5. Box e: Naked seeds
6. Box f: Angiosperms
7. Box g: Have seeds with two cotyledons
8. Box h: Monocots

Teacher's Note:
a) Plant classification is primarily based on plant body differentiation, presence of vascular tissues, and seed formation.
b) Thallophytes lack a well-differentiated body, while Pteridophytes, Gymnosperms, and Angiosperms possess vascular tissues.
c) Angiosperms are further divided into monocots and dicots based on the number of cotyledons in their seeds.

54. Which organism is more complex and evolved among Bacteria, Mushroom and Mango tree. Give reasons. [3 Marks]

Answer:
1. The Mango tree is the most complex and evolved organism among the three.
2. Bacteria are prokaryotic unicellular organisms with primitive cellular organization and no true nucleus.
3. Mushrooms are eukaryotic and multicellular (fungi), but they lack specialized vascular tissues and autotrophic nutrition.
4. The Mango tree is a highly evolved flowering plant (angiosperm) possessing specialized tissues (xylem and phloem), true roots, stems, leaves, flowers, and advanced organ systems for reproduction.

Teacher's Note:
a) Evolutionary complexity increases from prokaryotes to unicellular eukaryotes, multicellular non-vascular organisms, and finally to vascular seed-bearing plants.
b) Always compare cellular structure, mode of nutrition, and tissue differentiation to justify evolutionary advancement.
c) Mango trees belong to angiosperms, which represent the peak of plant kingdom evolution.

55. Differentiate between flying lizard and bird. Draw the diagram. [3 Marks]

[Figure: Diagram to be added showing the external morphological features of a flying lizard (Draco) with patagium and a bird with wings and feathers]

Answer:
1. Flying lizard belongs to class Reptilia, whereas bird belongs to class Aves.
2. The body of a flying lizard is covered with scales, whereas the body of a bird is covered with feathers.
3. Flying lizards glide using membranous extensions of skin called patagium, whereas birds use true wings modified from forelimbs for active flight.
4. Birds are warm-blooded (homeotherms), whereas flying lizards are cold-blooded (poikilotherms).

Teacher's Note:
a) Differentiate organisms using fundamental taxonomic classes and physiological traits like thermoregulation.
b) Note that the flying lizard does not use true wings for flapping flight like birds.
c) Diagrams should clearly label feathers, wings, scales, and patagium for full credit.

56. List out some common features in cat, rat and bat. [3 Marks]

Answer:
1. Cat, rat, and bat all belong to the class Mammalia.
2. They possess mammary glands for the nourishment of their young ones.
3. Their skin is covered with hair or fur, and they have external ears (pinnae).
4. They give birth to live young ones (viviparous, though exceptions exist in mammals, these three are placental mammals) and possess a four-chambered heart.

Teacher's Note:
a) Identifying the common taxonomic class is the key to listing shared features.
b) Students often get confused by the bat because it flies, but it is a mammal, not a bird.
c) Presence of hair and mammary glands are definitive mammalian characteristics.

57. Why do we keep both snake and turtle in the same class? [2 Marks]

Answer:
1. Both snakes and turtles belong to the same class, Reptilia, because they share common fundamental characteristics.
2. Both are cold-blooded (poikilothermic) animals, possess scales on their bodies, and breathe through lungs.

Teacher's Note:
a) Reptiles are characterized by being tetrapods with epidermal scales.
b) Despite having very different external body shapes and shells, their internal physiological systems place them in the same class.