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Q291.
Assertion (A): Segmentation is a characteristic feature of arthropods.
Reason (R): The phenomenon where the body is externally and internally divided into segments is called metamerism.
[Animal-Kingdom] [class-xi]
Correct option: A [ ]
Remark: Both A and R are true and R is the correct explanation of A. Explanation: Arthropods are segmented animals and metamerism refers to serial segmentation of the body.
Q292.
Assertion (A): The body of a hemichordate consists of a proboscis, collar, and trunk.
Reason (R): Hemichordates are bilaterally symmetrical, triploblastic, and coelomate animals.
[Animal-Kingdom] [class-xi]
Correct option: B [ ]
Remark: Both A and R are true but R is not the correct explanation of A. Explanation: Both statements describe hemichordate structure and body plan; the body divisions do not directly explain the germ layer/coelom condition.
Q293.
Assertion (A): Aves and Mammalia are grouped under Tetrapoda.
Reason (R): They bear two pairs of limbs.
[Animal-Kingdom] [class-xi]
Correct option: A [ ]
Remark: Both A and R are true and R is the correct explanation of A. Explanation: Aves and Mammalia are tetrapods characterized by two pairs of limbs a defining trait of Tetrapoda.
Q294.
Match List-I with List-II and select the correct option.
List-I (Distinctive Feature)
List-II (Phylum)
(a) Canal system
(i) Ctenophora
(b) Water vascular system
(ii) Annelida
(c) Metamerism (Segmentation)
(iii) Echinodermata
(d) Comb plates
(iv) Porifera
[Animal-Kingdom] [class-xi]
Correct option: A [ ]
Remark: (a) Canal system ? (iv) Porifera: Members of the Phylum Porifera (sponges) have a characteristic water transport or canal system where water enters through pores (ostia) into a central cavity.
(b) Water vascular system ? (iii) Echinodermata: The most distinctive feature of Phylum Echinodermata is the presence of a water vascular system, which aids in locomotion, food capture, and respiration.
(c) Metamerism ? (ii) Annelida: Phylum Annelida is characterized by metameric segmentation, where the body is externally and internally divided into repeating segments.
(d) Comb plates ? (i) Ctenophora: Phylum Ctenophora is distinguished by having eight external rows of ciliated comb plates, which are used for locomotion.
Remark: (a) Pneumatic bones ? (ii) Aves: Birds have hollow bones with air cavities (pneumatic) that reduce weight for flight. (b) Mammary glands ? (iv) Mammalia: Mammals are uniquely characterized by the presence of mammary glands for nourishing young. (c) Operculum ? (iii) Osteichthyes: Bony fishes have their gills covered by a bony flap called an operculum. (d) Poison sting ? (i) Chondrichthyes: Some cartilaginous fishes, such as Trygon (stingray), possess a poison sting.
Q297.
List-I (Class)
List-II (Distinctive Feature)
(a) Reptilia
(i) Dry cornified skin, Scales
(b) Aves
(ii) Feathers, Pneumatic bones
(c) Mammalia
(iii) Mammary glands, Hair
(d) Amphibia
(iv) Cloaca, Three-chambered heart
[Animal-Kingdom] [class-xi]
Correct option: C [ 3. (a)-(iv), (b)-(i), (c)-(ii), (d)-(iii) ]
Remark: (a) Reptilia ? (iv) Dry cornified skin, Scales: Reptiles are mostly terrestrial and their body is covered by dry, cornified skin with scales or scutes.
(b) Aves ? (i) Feathers, Pneumatic bones: Birds are characterised by feathers and hollow (pneumatic) bones for flight.
(c) Mammalia ? (ii) Mammary glands, Hair: Mammals possess mammary glands and hair.
(d) Amphibia ? (iii) Cloaca, Three-chambered heart: Amphibians have a cloaca and a three-chambered heart.
Q298.
Match List-I with List-II and select the correct option.
List-I (Phylum)
List-II (Distinctive Feature)
(a) Porifera
(i) Comb plates
(b) Coelenterata
(ii) Water vascular system
(c) Ctenophora
(iii) Cnidoblasts
(d) Echinodermata
(iv) Canal system
[Animal-Kingdom] [class-xi]
Correct option: A [ 1. (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii) ]
Remark: Porifera ? Canal system: Members of Phylum Porifera (sponges) show a water canal system with ostia and spongocoel.
Coelenterata (Cnidaria) ? Cnidoblasts: Presence of stinging cells (cnidoblasts) is characteristic.
Ctenophora ? Comb plates: Ctenophores bear eight rows of ciliated comb plates for locomotion.
Echinodermata ? Water vascular system: Echinoderms possess a water vascular system used in locomotion and food capture.
Q299.
List-I (Phylum)
List-II (Level of Organisation)
(a) Porifera
i) Organ system level
(b) Coelenterata
ii) Tissue level
(c) Platyhelminthes
iii) Cellular level
(d) Annelida
iv) Organ level
[Animal-Kingdom] [class-xi]
Correct option: C [ C ]
Remark: Porifera exhibits a cellular level of organisation, where cells are arranged as loose aggregates. Coelenterata has tissue level organisation. Platyhelminthes exhibits organ level organisation. Annelida has organ system level organisation.