A. Z- lines get closer
B. A band becomes short
C. 1 band elongates
D. There is no change in sarcomere
Related Mcqs:
- 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. - The contraction of which of the following muscle fibers, is controlled by hormones?
A. A smooth muscle
B. A cardiac muscle
C. A skeletal muscle.
D. All of these - 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 - In an annelids, the contraction of circular muscle results in___________?
A. Lengthening of the body.
B. Shortening of the body.
C. Widening of body
D. Thinning of body - Actin and myosin are the basic proteins involved in contractile machinery of our body to which type of proteins do they belong____________?
A. Globular proteins
B. Fibrous Proteins
C. Both a and b
D. None 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 - Detachment of myosin head and actin in rigor mortis occurs due to__________?
A. stored ATP in body
B. hypercalcemia
C. autolysis in body
D. hyperactivity of mitochondriaSubmitted by: Maryam Aftab
- The one which causes contraction of wall of the uterus during and after birth?
A. ADH
B. MSH
C. Oxytocin
D. Progesterone - Diameter of thick filament is____________?
A. 7 nm.
B. 8 nm
C. 16nm
D. 10-100 ?m. - 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
