IB Biology

What is the sliding filament theory?

• The sliding filament theory is a theory that explains how muscles relax.

• The sliding filament theory is a theory that explains how bones move.

• The sliding filament theory is a theory that explains how muscles contract.

• The sliding filament theory is a theory that explains how muscles grow.

Which proteins are involved in the sliding filament theory?

• collagen and elastin

• actin and myosin

• tubulin and keratin

• hemoglobin and insulin

What is the function of actin in muscle contraction?

• Actin regulates the release of calcium ions during muscle contraction.

• Actin stores energy for muscle contraction.

• Actin helps in the transmission of nerve impulses in muscle contraction.

• Actin provides the structural framework for muscle contraction and allows for the generation of force.

What is the function of myosin in muscle contraction?

• Myosin generates force for muscle contraction by interacting with actin.

• Myosin provides structural support to the muscle fibers.

• Myosin helps in muscle relaxation by inhibiting actin.

• Myosin is responsible for transmitting nerve signals to the muscles.

What is the role of calcium ions in muscle contraction?

• Calcium ions directly generate muscle contraction.

• Calcium ions bind to troponin and initiate muscle contraction.

• Calcium ions inhibit muscle contraction.

• Calcium ions have no role in muscle contraction.

Which of the following is the smallest unit of muscle contraction?

• myosin

• myofibril

• actin

• sarcomere

___are thin filaments.

• troponin

• tropomyosin

• actin

• myosin

___are thick filaments.

• actin

• myosin

• troponin

• tropomyosin

___are regulatory proteins that cover the myosin binding site on the actin.

• troponin-tropomyosin

• sarcomere

• sarcolemma

• sarcoplasmic reticulum

Calcium binds to ___of the troponin-tropomyosin complex.

• troponin

• tropomyosin

• actin

• myosin