Skeletal and Muscular System

Two adjoining vertebrae articulate with each other at three distinct joints. These include two facet joints (zygapophyseal joints) located dorsally and one intervertebral disc joint located ventrally between the vertebral bodies.

All chordates are characterised by three primary chordate features the presence of a notochord, a dorsal hollow nerve cord and paired pharyngeal gill slits. The notochord, later on, gives rise to a bony vertebral column, which surrounds and protects the spinal cord. So, the correct answer is option B.

The axis vertebra, which is the second cervical vertebra, is uniquely identified by the presence of the odontoid process, also known as the dens. This bony projection acts as a pivot around which the atlas vertebra and skull rotate.

The axis vertebra is characterized by the odontoid process, which allows for the rotation of the head.

Pelvic girdle comprises of the usual three bones ilium, ischium and pubis which are fused together into a single innominate or hip bone.

In rabbit, radius and ulna are separate bones but they are joined at both ends by ligaments.

Skeletal muscles show muscle fibres having well developed sarcoplasmic reticulum these muscles are easily fatigued during exercise. Skeletal muscles show voluntary movements.  These can be found in close association with limb bones.

The biceps, also known as biceps brachii lies on the front of the upper arm between the shoulder and the elbow. The biceps brachii has two heads, or origins. Both heads originate on the scapula. The long head attaches to the supraglenoid tubercle of the scapula, which is just above the space where the humerus, or upper arm, enters the shoulder. The short head attaches to the coracoid process of the scapula. Both heads converge into one muscle, that runs the length of the humerus. The biceps brachii crosses the inside of the elbow and attaches at the radial tuberosity, which is a feature on the radius - one of the two bones (Ulna is other bone) in- the lower arm. In this way it attaches humerus with the radius and ulna. 

It forms the main axis. It consists of skull - 22 bones vertebral column - 33 vertebrae, sternum - 1 and ribs - 24.

A- The glenoid cavity or glenoid fossa of scapula is a part of the shoulder. It is a shallow, pyriform articular surface, which is located on the lateral angle of the scapula.

• The phalanges are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges.
•  Hence, Phalanges are present in both hands and foot.
• The mandible is the largest, strongest and lowest bone in the human face. It forms the lower jaw and holds the lower teeth in place. The mandible is the only movable bone of the skull, not counting the ossicles of the middle ear.
• Hence, Mandible is the only movable bone in the skull of the man.
• So, the correct answer is 'Phalanges - Mandible'.

The hip joint is a synovial joint formed by the articulation of the rounded head of the femur and the cup-like acetabulum of the pelvis. The cup-like acetabulum forms at the union of three pelvic bones - the ilium, pubis, and ischium. 

Pelvic girdle consists of two coxal bones. Each coxal bone is formed by the fusion of three bones ilium, ischium and pubis. At the point of fusion of the above bones is a cup shaped cavity called as acetabulum to which the thigh bone articulates. The two halves of the pelvic girdle meet ventrally to form the pubic symphysis containing fibrous cartilage.

The bones of the limbs along with their girdles constitute the appendicular skeleton. Each limb is made of 30 bones. The bones of the hand (fore limb) are humerus, radius and ulna, carpals (or wrist bones 8 in number), metacarpals (palm bones, 5 in number) and phalanges (digits 14 in number).