Prepare for NEET Biology Locomotion And Movement with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert explanations of muscles and skeleton.
A unique characteristic of the ciliary movement is its:
Dependence on calcium ions for power stroke
Presence of a central sheath connecting microtubule doublets
Sliding filament mechanism involving actin and myosin
Metachronal rhythm leading to unidirectional flow
Which of the following is NOT associated with muscle contraction?
Release of calcium ions from the sarcoplasmic reticulum
Binding of calcium ions to troponin
Sliding of actin filaments over myosin filaments
Depolymerization of microtubules
The movement of flagella is primarily driven by:
Actin-myosin interaction
Dynein-mediated sliding of microtubules
Hydrostatic pressure changes
Calcium influx into the flagellar matrix
Which of the following is NOT a characteristic of smooth muscle?
Involuntary control
Presence of gap junctions
Presence of T-tubules
Slow, sustained contractions
The specialized synapse between a motor neuron and a skeletal muscle fiber is called the:
Synaptic cleft
Myoneural junction
Neuromuscular junction
Motor end plate
Which unique characteristic of cardiac muscle allows for coordinated contraction of the heart?
Multinucleated fibers
Fusiform shape
Intercalated discs
Absence of striations
A defect in dystrophin protein primarily affects which type of muscle tissue and leads to what condition?
Smooth muscle; Myasthenia gravis
Cardiac muscle; Myocardial infarction
Skeletal muscle; Muscular dystrophy
Cardiac muscle; Arrhythmia
Rigor mortis, the stiffening of muscles after death, occurs because:
$Ca^{2+}$$ influx into the sarcoplasm ceases.
Troponin-tropomyosin complex permanently blocks myosin binding sites.
ATP depletion prevents detachment of myosin heads from actin.
Acetylcholine is no longer released at the neuromuscular junction.
In a skeletal muscle fiber, during a single twitch, the amount of tension generated during the contraction phase is directly proportional to:
The concentration of ATP in the sarcoplasm
The duration of the action potential
The frequency of nerve stimulation
The number of cross-bridges formed between actin and myosin
Which of the following statements accurately describes the role of ATP in muscle contraction?
ATP hydrolysis provides energy for the power stroke, but not for detachment of myosin from actin.
ATP binding to myosin causes the power stroke.
ATP is only required for the detachment of myosin heads from actin.
ATP is required for both the attachment and detachment of myosin heads to actin.
