Answer:
C
Explanation:
The major histocompatibility complex (MHC) is a group of genes whose function is to codify proteins that participate in the immune response, helping the system to <u>recognize foreign substances to develop an immune response</u>. 
<u>Histocompatibility or compatibility of tissue </u>is given by self-identifications molecules (antigens) located on the surface of cells, membrane, these molecules are almost <u>unique to each person</u>, letting the body to distinguish self from non-self. 
 
        
             
        
        
        
Answer:
DNA replication
Explanation:
DNA replication is the process whereby the genetic material (DNA) duplicates itself into two identical copies. This process must occur prior to any cellular division (meiosis or mitosis) in order to ascertain that each daughter cell gets an even and correct amount of DNA. 
The process of DNA replication begins with the unwinding of the double stranded DNA molecule into two single strands of DNA. One strand called leading strand runs from 3'-5' while the other strand runs from 5'-3'. However, DNA replication proceeds in the 5'-3' direction. 
 
        
             
        
        
        
Ans. 
Genetic codes provide information for the protein synthesis as each code specifically codes a particular amino acid that gets joined in polypeptide chain during the process of translation. 
Each genetic code is three letter code, made up of three nitrogenous bases. There are four different bases in DNA or RNA that make sixty four codes with different combinations, out of which sixty one code for amino acids and three act as stop codons.
Thus, nitrogenous bases are important in preserving the genetic codes. 
 
        
             
        
        
        
Answer: Theoretrical framework
Explanation: got it right on apex