Free Support and Movement MCQs with Answers

51. Calcium binds to

• A. Actin
• B. Myosin
• C. Troponin
• D. Tropomyosin

Explanation: Ca2+ binds to troponin, causing tropomyosin to move and expose myosin-binding sites on actin.

52. ATP is required for muscle contraction for

• A. Only cross-bridge formation
• B. Only cross-bridge detachment
• C. Both formation and detachment
• D. Neither

Explanation: ATP is required for myosin head cocking (after power stroke) and detachment from actin.

53. Bone is composed of

• A. Only collagen
• B. Only calcium phosphate
• C. Collagen and calcium phosphate
• D. Cartilage only

Explanation: Bone contains organic collagen (flexibility) and inorganic calcium phosphate/hydroxyapatite (hardness).

54. Synovial joints are characterized by

• A. No movement
• B. Presence of synovial fluid
• C. Cartilage only
• D. Fibrous capsule only

Explanation: Synovial joints (freely movable) contain synovial fluid for lubrication and nutrition of articular cartilage.

55. Osteoblasts are

• A. Bone-destroying cells
• B. Bone-forming cells
• C. Mature bone cells
• D. Fat cells in bone

Explanation: Osteoblasts are bone-forming cells that secrete collagen and matrix, later becoming osteocytes.

56. Ligaments connect

• A. Muscle to bone
• B. Bone to bone
• C. Muscle to muscle
• D. Cartilage to cartilage

Explanation: Ligaments connect bone to bone, providing joint stability. Tendons connect muscle to bone.

57. Rigor mortis occurs due to

• A. Excess ATP
• B. Lack of ATP
• C. Excess calcium
• D. Lack of calcium

Explanation: Without ATP, myosin heads cannot detach from actin, causing persistent muscle contraction (rigor mortis).

58. The A-band contains

• A. Only actin
• B. Only myosin
• C. Both actin and myosin
• D. Neither

Explanation: The A-band (dark) contains the entire length of myosin filaments and overlapping actin filaments.

59. Which is the common feature between cardiac and smooth muscles?

• A. Voluntary
• B. Involuntary
• C. Branched
• D. Unbranched

Explanation: Both contract without conscious control, cardiac muscle beating rhythmically on its own and smooth muscle working the gut, blood vessels and other hollow organs. They differ in almost everything else: cardiac fibres are branched and striated while smooth fibres are unbranched and non striated, which is why the third and fourth options each apply to one but not both. Only skeletal muscle is voluntary.

60. The joints which cause rotational movements are

• A. Hinge
• B. Ball and Socket
• C. Cartilage
• D. Sutures

Explanation: A ball and socket joint such as the shoulder or hip allows movement in every plane including rotation, because the rounded head can turn freely within its cup. A hinge joint like the elbow is restricted to one plane and permits no rotation at all. Sutures between the skull bones are immovable and cartilaginous joints allow only slight movement.