Insertion of Biceps is on_________?

A. Ulna
B. Radius
C. Olecronon process of ulna.
D. Scapula

Rigor mortis i.e, stiffening of body after death results from__________?

A. Accunulation of rigid proteins molecules in sarcoplam.
B. Unavailability of atp, which is necessary to break the link between actin and myosin.
C. Decrease in body temperature after death.
D. Death of tissue due to unavailability of o2.

Which of the following statement about fatigue is correct?

A. The major event in it is accumulation of lactic acid.
B. Lactic acid accumulation turns ph in acidic range leading to muscle ache.
C. Ionic imbalance may also cause it.
D. All of these

Tetany is caused by__________?

A. Hypocalcemia
B. Hypercalcemia
C. Clostridum tetani.
D. Low o2 level

The most important function of troponin is___________?

A. To bind with actin
B. To bind with tropomyosin.
C. To bind with ca2+ ions.
D. All of these

If a cross section of a sarcomere is seen, each myosin is surrounded by how many actin molecules:

A. 9
B. 5
C. 6
D. 7

What happens during muscle contraction to the length of each myosin and action filament?

A. Z- lines get closer
B. A band becomes short
C. 1 band elongates
D. There is no change in sarcomere

Which of the following step occurs immediately after binding of Ca2+ with troponin molecule during muscle contraction.

A. Binding sites of actin get attached to the myosin head.
B. Troponin uncovers the actin binding sites.
C. Tropomyosin gets removed from the binding sites of actin filaments.
D. Ca2+ goes back inside sarcoplasmic reticulum.

Which of the following statements is incorrect about skeletal muscle fibers?

A. They are multinucleated.
B. They are 10 – 100 ?m in diameter & surrounded by sarcolemma
C. They contain o2 storing molecules called hemoglobin.
D. Their cytoplasm contains high concentration of carbohydrates

A smallest contractile unit of muscle contraction called sarcomere is the area between two:

A. H- zone
B. M- line
C. Z- line
D. A band