Study the events given below. Identify the set given in the choice that has the events in correct chronological order of their occurrence:
a. Ca2+ combines with tropomyosin
b. Ca2+ combines with troponin
c. tropomyosin pulls away from actin
d. troponin pulls away from actin
e. tropomyosin pulls away from myosin
f. troponin pulls away from myosin
g. myosin binds to actin
1. | a, d, g | 2. | b, e, f |
3. | a, c, g | 4. | b, c, g |
The majority of the muscle fibers in the skeletal muscles of the leg of a long distance runner is expected to have:
1. adaptation for sudden outburst of activity
2. primarily anaerobic source of energy
3. numerous mitochondria
4. large deposits of glycogen
During relaxation in smooth muscle:
1. calcium is removed from troponin.
2. bind to calmodulin.
3. myosin phosphatase removes phosphate from myosin.
4. Calcium is released from the sarcoplasmic reticulum.
Cylindrical, branched muscle cells that are arranged into functional syncytium are:
1. cardiac muscles.
2. skeletal muscles.
3. single unit smooth muscles.
4. multi unit smooth muscles.
A muscle cell is called as a:
1. | sarcomere | 2. | fiber |
3. | myofibril | 4. | myofilament |
All the following are parts of the actin myofilament in a sarcomere except:
1. actin
2. cisternae
3. tropomyosin
4. troponin
An ATPase activity is associated with:
1. G actin molecule
2. head of myosin molecule
3. troponin molecule
4. F actin
Overlap between actin and myosin myofilaments in a sarcomere is seen in:?
1. A band
2. H zone
3. I band
4. M line
The Z line is present in:
1. | A band | 2. | H zone |
3. | I band | 4. | M line |
The drug curare causes:
1. flaccid paralysis.
2. spastic paralysis.
3. smooth muscle degeneration.
4. cardiac failure.