Q.5 - Biology

Question

The pectoral girdle consists of the: 

a. clavicle and sternum 

b. sternum and scapula 

c. clavicle and scapula 

d. clavicle and coccyx 

Step-by-Step Solution

Answer

The correct answer is (c) clavicle and scapula  

The pectoral girdle consists of the clavicle and scapula.  

Step 1. Introduction

The pectoral girdle is a part of the appendicular skeleton, which connects the upper limbs to the axial skeleton. The human skeleton is divided into two sections, the axial skeleton and the appendicular skeleton.

Step 2. Explanation for the correct answer

(c) clavicle and scapula  

Pectoral girdle can be divided into two equal halves. Each half of the pectoral girdle consists of two bones, namely scapula (shoulder blade) and clavicle (collar bone). 

Scapula (Shoulder blade)

• It is a triangular-shaped flat bone, which forms the posterior side of the shoulder. It is present dorsally in the thorax region between the second and the seventh ribs.

Clavicle (Collar bone)

• It is a long s-shaped bone, which forms the anterior part of the pectoral girdle. It is present horizontally and is also known as the collar bone.

Step 3. Explanation for the incorrect answer

a. clavicle and sternum 

• The sternum is a partially T-shaped vertical bone that forms the anterior portion of the chest wall centrally.
• The pectoral girdle consists of the clavicle and scapula. Hence, this option is not correct. 

b. sternum and scapula 

• The pectoral girdle consists of the clavicle and scapula. Hence, this option is not correct. 

d. clavicle and coccyx 

• The coccyx, also known as the tailbone, is a small, triangular bone resembling a shortened tail located at the bottom of the spine.
• The pectoral girdle consists of the clavicle and scapula. Hence, this option is not correct.