Browse exam-wise, subject-wise, and country-wise MCQs with explanations.
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Smooth muscle occurs in walls of organs such as blood vessels and digestive tract. It supports involuntary movements rather than voluntary limb movement.
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Skeletal muscle contraction depends on actin and myosin filaments sliding past one another. Blocking their interaction prevents force production and therefore movement.
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A flagellum produces wave-like motion that propels a sperm cell. It is a cellular movement mechanism, not a skeletal or circulatory adaptation.
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Paramecium uses coordinated ciliary beating for swimming and feeding currents. It lacks muscles and a skeleton, so movement is cellular rather than organ-system based.
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Cilia are cell surface organelles that create movement or water currents by coordinated beating. This differs from movement produced by muscles pulling on skeletons.
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Calcium salts are important for mineralization and hardness of vertebrate bone. Poor mineral availability can weaken skeletal strength and normal support.
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Bird skeletons contain lightweight adaptations while still providing rigid support. This combination helps flight by lowering mass without sacrificing wing control.
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Jumping in frogs depends on strong hind limb muscles acting on skeletal levers. Bones and joints convert muscle contraction into powerful movement.
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The vertebrate skeleton supports the body and works with muscles and fins to produce swimming movements. Its flexibility and segmental arrangement are linked to aquatic locomotion.
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The molluscan shell protects soft tissues and provides attachment points for muscles such as adductor muscles. It is not the main system for endocrine control or nerve conduction.
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A hydrostatic skeleton uses incompressible body fluid and muscle contractions to change body shape. Earthworms use circular and longitudinal muscles with coelomic fluid for burrowing locomotion.
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Arthropod muscles attach to the inner surfaces of the exoskeleton. Contraction moves jointed appendages, making the exoskeleton both protective and mechanical support.
