Name the ion responsible for the 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

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

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

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. α-actinin
4. troponin

If a stimulus, several times greater than the threshold stimulus, is provided to a muscle fiber, it will
1. Contract with a larger force
2. Contract with a smaller force
3. Contract with the same force
4. Undergo tetany

Which one of the following is a sesamoid bone?
1. Pelvis
2. Patella
3. Pterygoid
4. Pectoral girdle

Given diagram shows bone of the left human hind limb as seen from front. It has certain mistakes in labeling. Two of the wrongly labelled bones are
    

Consider the following statements:
I. A motor neuron along with the muscle fibres connected to it constitute a motorunit.
II. The neurotransmitter released at the neuro-muscular junction is Acetylcholine.
III. Myosin head has ATPase activity.
Which of the above statements are true?
1. I and II only           2. I and III only
3. II and III only        4. I, II, and III