Q11. Which class within the subphylum Vertebrata includes animals with mammary glands for lactation?
a) Amphibia
b) Reptilia
c) Aves
d) Mammalia
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Correct Answer: d) Mammalia
Explanation: Mammals, belonging to the class Mammalia, are characterized by the presence of mammary glands, which produce milk for nourishing their young. They also possess hair or fur, a differentiated dentition, and a four-chambered heart.
Q12. Animals in the class Amphibia typically undergo which type of metamorphosis?
a) Incomplete metamorphosis
b) Holometabolous metamorphosis
c) Hemimetabolous metamorphosis
d) Direct development
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Correct Answer: a) Incomplete metamorphosis
Explanation: Amphibians typically undergo incomplete metamorphosis, characterized by a larval stage that resembles the adult but lacks certain adult features, such as limbs or lungs. The larva undergoes gradual transformation into the adult form through a series of molts.
Q13. Which of the following is a characteristic feature of animals in the class Mammalia?
a) Presence of feathers
b) Internal fertilization
c) Ectothermy
d) Oviparous reproduction
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Correct Answer: b) Internal fertilization
Explanation: Mammals possess internal fertilization, meaning fertilization occurs inside the female’s body. This adaptation allows for greater protection of developing embryos and offspring, as well as the possibility of parental care.
Q14. The subphylum Vertebrata includes animals with which of the following types of symmetry?
a) Bilateral symmetry
b) Radial symmetry
c) Asymmetry
d) Spiral symmetry
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Correct Answer: a) Bilateral symmetry
Explanation: Vertebrates exhibit bilateral symmetry, meaning their body can be divided into two mirror-image halves along a single plane. This symmetry allows for directional movement and organization of sensory organs and appendages.
Q15. The notochord in chordates serves primarily as:
a) A site for muscle attachment
b) A support structure
c) A respiratory organ
d) A digestive organ
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Correct Answer: b) A support structure
Explanation: The notochord in chordates serves primarily as a support structure, providing rigidity and support to the body. It also serves as a developmental scaffold around which the vertebral column forms in vertebrates.
Q16. The pharyngeal gill slits found in chordates function primarily in:
a) Respiration
b) Filter feeding
c) Excretion
d) Sensory perception
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Correct Answer: b) Filter feeding
Explanation: Pharyngeal gill slits in chordates primarily function in filter feeding. In primitive chordates such as lancelets and tunicates, these slits allow water to pass through the pharynx, where food particles are trapped and ingested while excess water is expelled.
Q17. The dorsal nerve cord found in chordates is part of the:
a) Peripheral nervous system
b) Autonomic nervous system
c) Central nervous system
d) Enteric nervous system
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Correct Answer: c) Central nervous system
Explanation: The dorsal nerve cord in chordates is part of the central nervous system. It serves as a conduit for transmitting sensory information from the body to the brain and motor signals from the brain to the body.
Q18. Which of the following structures is derived from the embryonic notochord in vertebrates?
a) Brain
b) Spinal cord
c) Vertebral column
d) Heart
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Correct Answer: c) Vertebral column
Explanation: In vertebrates, the embryonic notochord gives rise to the vertebral column, also known as the backbone or spine. The vertebral column provides structural support and protection for the spinal cord and serves as attachment sites for muscles.
Q19. The presence of a cranium is a characteristic feature of which group of chordates?
a) Urochordata
b) Cephalochordata
c) Vertebrata
d) Hemichordata
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Correct Answer: c) Vertebrata
Explanation: Vertebrates, belonging to the subphylum Vertebrata, possess a cranium, which is a bony or cartilaginous structure surrounding and protecting the brain. The cranium is a key evolutionary innovation that distinguishes vertebrates from other chordates.
Q20. Which of the following is a characteristic feature of chordates during at least some stage of their development?
a) Post-anal tail
b) Exoskeleton
c) Jointed appendages
d) Compound eyes
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Correct Answer: a) Post-anal tail
Explanation: A post-anal tail is a characteristic feature of chordates during at least some stage of their development. In vertebrates, the tail may be present during embryonic development and is typically lost or reduced in adults of some species.