IB Bio 11.2

What is the order of increasing size of muscle structures?

• A. muscle, muscle fibre, myofibril, sarcomere

• B. myofibril, muscle fibre, sarcomere, muscle

• C. sarcomere, myofibril, muscle fibre, muscle

• D. muscle fibre, sarcomere, myofibril, muscle

What are features of both endoskeletons of mammals and exoskeletons of insects?

• A. They are both made of bone.

• B. They both have cartilage.

• C. They are both moved by antagonistic sets of muscles.

• D. Both consist of dead tissue.

What is the role of the joint capsule in an elbow joint?

• A. It seals the joint to retain the synovial fluid.

• B. It provides a point of attachment for muscles.

• C. It produces cartilage to reduce friction during movement. Clumping due to antibody reaction

• D. It directs the formation of bone tissue during growth and development.

What is the role of the joint capsule in an elbow joint?

• A. It seals the joint to retain the synovial fluid.

• B. It provides a point of attachment for muscles.

• C. It produces cartilage to reduce friction during movement. Clumping due to antibody reaction

• D. It directs the formation of bone tissue during growth and development

What is a similarity between human and insect muscles?

• A. They are attached to an exoskeleton.

• B. They work as antagonistic pairs.

• C. The flexor muscles straighten the joint.

• D. They move bones.

What is the role of calcium ions in muscle contraction?

• A. To enable actin to expose binding sites on myosin

• B. To bind to troponin, exposing binding sites on actin

• C. To prevent an action potential in the muscle membrane

• D. To bind to tropomyosin, blocking binding sites on actin

The diagram shows structures involved in contraction of a sarcomere.

What is X?

• A. Myosin filament

• B. Sarcomere

• C. Actin filament

• D. Myofibril

The diagram represents a sarcomere. Which structure is myosin?

• A.

• B.

• C.

• D.

What is the role of calcium in muscle contraction?

• A. To release tropomyosin from myosin

• B. To bind to troponin so myosin-binding sites on actin are exposed

• C. To bind to tropomyosin so ATP can bind to actin

• D. To release ATP from actin so myosin can bind to troponin

Which process is part of the mechanism that controls muscle contraction?

• A. Troponin enables actin heads to attach to ATP and slide along myosin.

• B. Myosin heads attach to troponin and tropomyosin pulls on actin filaments.

• C. Tropomyosin attaches to calcium and breaks the bond between actin and myosin.

• D. Calcium frees actin filaments for myosin heads to attach.