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Q191.
Animals possessing a notochord only during the embryonic period belong to the subphylum __________.
[Animal-Kingdom] [class-xi]
Correct option: C [ Urochordata ]
Remark: In Urochordates (like Ascidia), the notochord is present only in the larval stage and disappears in the adult, whereas in Cephalochordates it persists throughout life.
Q192.
In most coelenterates, the body shows __________ symmetry and the arrangement of cells is __________.
[Animal-Kingdom] [class-xi]
Correct option: B [ Radial; Diploblastic ]
Remark: Coelenterates (Cnidarians) exhibit radial symmetry, meaning their body parts are arranged around a central axis. They are diploblastic, derived from two embryonic layers — ectoderm and endoderm — with a non-cellular mesoglea in between.
Q193.
Homoiothermous (warm-blooded) animals are characterized by __________.
[Animal-Kingdom] [class-xi]
Correct option: C [ The ability to maintain a constant body temperature ]
Remark: Homoiothermous (warm-blooded) animals, like birds and mammals, are able to maintain a constant internal body temperature regardless of the external environment.
Q194.
The digestive tract of birds has additional chambers called the __________.
[Animal-Kingdom] [class-xi]
Correct option: C [ Crop and gizzard ]
Remark: The digestive tract of birds has two additional chambers: the crop for storing food and the gizzard for grinding it.
Q195.
The most unique mammalian characteristic is the presence of __________.
[Animal-Kingdom] [class-xi]
Correct option: C [ Milk producing glands (mammary glands) ]
Remark: The most unique characteristic of mammals is the presence of milk-producing mammary glands used to nourish their young.
Q196.
Which of the following is an oviparous (egg-laying) mammal? __________
[Animal-Kingdom] [class-xi]
Correct option: D [ Ornithorhynchus (Platypus) ]
Remark: While most mammals are viviparous (give live birth), there are exceptions. The Platypus (Ornithorhynchus) is an oviparous mammal, meaning it lays eggs.
Q197.
In Arthropoda, the body cavity is filled with blood and is therefore called a __________.
[Animal-Kingdom] [class-xi]
Correct option: C [ Haemocoel ]
Remark: In arthropods, the true coelom is reduced and replaced by a haemocoel, a cavity filled with blood (haemolymph). Their circulatory system is open type, meaning blood does not flow entirely within vessels.
Q198.
The water vascular system is a characteristic of which group? __________
[Animal-Kingdom] [class-xi]
Correct option: C [ Echinodermata ]
Remark: The water vascular system is the characteristic and most distinctive feature of the phylum Echinodermata.
Q199.
In which of the following phyla is segmentation first observed? __________
[Animal-Kingdom] [class-xi]
Correct option: C [ Annelida ]
Remark: Body segmentation (metamerism) is first observed in the Phylum Annelida.
Q200.
Assertion (A): The classification of over a million animal species is important.
Reason (R): Classification helps in assigning a systematic position to newly described species.
[Animal-Kingdom] [class-xi]
Correct option: A [ ]
Remark: Both A and R are true and R is the correct explanation of A. Explanation: The need for classification is important precisely because it allows for the systematic placement of newly discovered species among the vast number of known species.