Which component of the skeletal muscle fibre is primarily responsible for muscle contraction?

A. Endomysium

B. Perimysium

C. Myofibril

D. Epimysium

What is the primary function of synovial joints in the human body?

A. Providing structural support

B. Facilitating movement

C. Producing red blood cells

D. Storing calcium ions

How do ATP hydrolysis and calcium ions contribute to muscle contractions?

A. By inhibiting actin and myosin interaction

B. By promoting the relaxation of muscle fibres

C. By enabling the cross-bridge cycle and regulating troponin-tropomyosin complex

D. By decreasing the sensitivity of muscle fibres to neural stimuli

Which structure is essential for the sliding filament theory of muscle contraction?

A. Sarcomere

B. Sarcoplasmic reticulum

C. T-tubule

D. Mitochondrion

What role do bones play in movement?

A. Providing energy for muscle contraction

B. Acting as levers and providing structural support

C. Producing synovial fluid for joint lubrication

D. Regulating the contraction of muscle fibres

a) Discuss the role of bones in movement and how they interact with skeletal muscle fibres. [3]

b) Explain the sliding filament theory of muscle contraction involving actin and myosin. [4]

a) Describe the function of synovial joints and how they facilitate movement. [3]

b) Discuss the role of ATP hydrolysis, calcium ions, and proteins in muscle contractions. [4]

a) Discuss the structure of skeletal muscle fibres and how this structure is adapted for contraction. [4]

b) Explain the role of myofibrils and sarcomeres in muscle contraction. [3]

a) Explain the concept of the sliding filament theory and how it contributes to muscle contraction. [3]

b) Discuss the role of calcium ions in the sliding filament theory. [2]

c) How does ATP hydrolysis facilitate the detachment of myosin heads from actin filaments during muscle contraction? [3]

a) Describe the function and structure of synovial joints. [3]

b) How do bones and skeletal muscle fibres interact to facilitate movement? [3]

c) Discuss the significance of exoskeletons in the movement of arthropods. [2]