Only the bases varies from one nucleotide to another.
        
                    
             
        
        
        
Answer: b - Chondroblasts within the cartilage divide and secrete new matrix
Explanation: Chondroblasts are derived from two sources; mesenchymal cells within the center of chondrification and chondrogenic cells of the inner cellular layer of the perichondrium (coverings that lie over most cartilage). 
At the chondrification centers, the cartilage forming cells (Chondroblasts) begin to secrete the components of extracellular matrix of cartilage. As the amount of matrix increases, the Chondroblasts become separated from each other and they are located in small cavity within the matrix called lacunae. 
Concurrently, the cells differentiate into matured cartilage cells called chondrocytes. 
 
        
             
        
        
        
B - store and transmit hereditary information
 
        
             
        
        
        
Answer:It is called The Foramen Magnum
Explanation: It is a large oval opening linking the Spinal cord and the Brain
Hope this helps : )