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Q411.
Cnidocytes are specialized cells used for?
[Animal-Kingdom] [class-xi]
Correct option: C [ Defense and prey capture ]
Remark: Cnidocytes (or cnidoblasts) contain stinging capsules called nematocysts. They are used for anchorage, defense against predators, and capturing prey.
Q412.
Choanocytes (Collar cells) are characteristic of which Phylum?
[Animal-Kingdom] [class-xi]
Correct option: B [ Porifera ]
Remark: Choanocytes are specialized flagellated collar cells found lining the spongocoel and canals of sponges (Porifera). They generate water currents and help in filtering food.
Q413.
Which group possesses a persistent notochord throughout their entire life?
[Animal-Kingdom] [class-xi]
Correct option: B [ Chondrichthyes ]
Remark: Chondrichthyes (cartilaginous fishes like sharks and rays) retain the notochord throughout their adult life, unlike Osteichthyes where it is largely replaced.
Q414.
The Water Vascular System is a unique characteristic of which Phylum?
[Animal-Kingdom] [class-xi]
Correct option: B [ Echinodermata ]
Remark: The Water Vascular System is a distinct hydraulic system found only in Echinoderms. It aids in functions like locomotion, food capture, and transport.
Q415.
Which of the following is NOT a direct function of the Water Vascular System?
[Animal-Kingdom] [class-xi]
Correct option: D [ Digestion ]
Remark: While the Water Vascular System helps in locomotion, capture and transport of food, and respiration/excretion, digestion itself is a function of the digestive system, not the vascular system.
Q416.
Which locomotory structures in Echinoderms are connected to the Water Vascular System?
[Animal-Kingdom] [class-xi]
Correct option: B [ Tube feet ]
Remark: Tube feet (podia) are small, active tubular projections connected to the Water Vascular System. They are the primary organs for locomotion in Echinoderms.
Q417.
Sponges are placed in Phylum Porifera primarily due to the presence of?
[Animal-Kingdom] [class-xi]
Correct option: B [ Water Canal System ]
Remark: The Water Canal System is the defining characteristic of Porifera. It creates a path for water flow which brings in food and oxygen and removes waste.
Q418.
Which organ is typically absent in birds to reduce body weight for flight?
[Animal-Kingdom] [class-xi]
Correct option: C [ Urinary Bladder ]
Remark: To minimize body weight and facilitate flight, most birds lack a urinary bladder. They excrete nitrogenous waste as uric acid paste rather than storing liquid urine.
Q419.
Which bird is an exception to the rule and possesses a urinary bladder?
[Animal-Kingdom] [class-xi]
Correct option: B [ Ostrich ]
Remark: The Ostrich is a flightless bird and is a notable exception among aves as it possesses a urinary bladder for storing urine.
Q420.
The primary excretory organ in all Chordates (Vertebrates) is the?
[Animal-Kingdom] [class-xi]
Correct option: C [ Kidney ]
Remark: Kidneys are the paired organs responsible for excretion and osmoregulation in all vertebrates (chordates), filtering blood to remove waste products.