What is the primary function of cardiac muscle tissue?

• Regulating the size of the iris

• Voluntary movements of the body

• Pumping blood throughout the body

• Digesting food

Which muscle tissue type is characterized by involuntary control?

• Cardiac muscle tissue

• None of the above

• Skeletal muscle tissue

• Both smooth and cardiac muscle tissues

Which muscle tissue is responsible for voluntary movements?

• Smooth muscle tissue

• Cardiac muscle tissue

• Skeletal muscle tissue

• None of the above

How do skeletal muscles attach to bones?

• Through tendons

• Through ligaments

• Directly without any connecting tissue

• Through cartilage

What is the significance of sarcomeres in muscle fibers?

• They produce myosin

• They transport calcium ions

• They are the basic unit of contraction in muscle fibers

• They store ATP

Which proteins are involved in muscle contraction?

• Actin and Troponin

• Actin and Myosin

• Myosin and Tropomyosin

• Troponin and Tropomyosin

What causes the sliding of thin filaments towards the center of the sarcomere?

• The shortening of thick filaments

• The binding of ATP to actin

• The movement of Z lines

• The power stroke of myosin heads

What is the role of ATP in muscle contraction?

• It prevents contraction

• It causes the myosin heads to detach from actin

• It blocks the myosin binding sites on actin

• It is not involved in muscle contraction

What happens when calcium ions bind to troponin?

• ATP is hydrolyzed

• Tropomyosin moves off the myosin binding sites on actin

• Tropomyosin blocks the myosin binding sites on actin

• Muscle contraction stops