Name the ion responsible for unmasking of active sites for myosin for cross-bridge activity during muscle contraction.

(1)  Calcium              

(2)  Magnesium

(3)  Sodium              

(4)  Potassium.

Lack of relaxation between successive stimuli in sustained muscle contraction is known as 

(1) fatigue   

(2) tetanus   

(3) tonus   

(4) spasm

Which of the following is not a function of the skeletal system?

1. Production of erythrocytes

2. Storage of minerals

3. Production of body heat

4. Locomotion

Sliding filament theory can be best explained as

1. when myofilaments slide pass each other actin filaments shorten while myosin

filament do not shorten

2. actin and myosin filaments shorten and slide pass each other

3. actin and myosin filaments do not shorten but rather slide pass each other

4. when myofilament slide pass each other myosin filament shorten while actin filaments

do not shorten

Select the correct matching of the type of the joint with the example in human skeletal

system

Types of joint                                     Example

1.  Cartilaginous joint                   Between frontal and parietal

2.  Pivot joint                               Between third and fourth Cervical vertebrae

3. Hinge joint                               Between humerus and pectoral girdle

4. Gliding joint                             Between carpals 

The characteristics and an example of a synovial joint in humans is 

Which one of the following items gives its correct total number?

1.  Floating ribs in humans           - 4 

2.  Amino acids found in proteins  -16

3.  Types of diabetes                   - 3

4.  Cervical vertebrae in humans  - 8

In human body, which one of the following is anatomically correct ?

1. Floating ribs-2 pairs

2. Collar bones-3 pairs

3. Salivary glands-1 pair

4. Cranial nerves-10 pairs

The contractile protein of skeletal muscle involving ATPase activity is :

1. tropomyosin                 

2. myosin       

3. $\mathrm{\alpha }$-actinin                     

4. troponin

The process by which most of the cartilaginous tissue is transformed into bones is

1. endochondral ossification

2. intermembranous ossification

3. calcification

4. none of the above