Answer:
Sequence of nucleotides in the DNA strand
Explanation:
Deoxyribonuceic acid or DNA is a biological material that stores the genetic information of an organism. 
DNA encodes the information through the order or sequence of the nuceotides along each strand. Organisms differ from one another because their respective DNA molecule have different nucleotide sequences and consequently, carry different biological instructions.
A DNA strand consists of two polynucleotide chains, composed of four nucleotide subunits. Each of these chains is known as DNA strand. Hydrogen bonds between the base portions of the nucleotides hold the two chains together. DNA nucleotides are composed of a 5-carbon sugar (Deoxyribose) to which are attached one phosphate group and a nitrogenous base (Adenine, Guanine, Cytosine and Thymine). The nucleotides are covalently linked together.
 
        
             
        
        
        
The process of making multiple copies of a gene by inserting it into a host genome and culturing the host is an example of gene cloning.
        
             
        
        
        
Answer:
A. is repeated many times to ensure that the results are accurate 
Explanation:
A controlled experiment is repeated many times to ensure that the results are accurate 
 
        
                    
             
        
        
        
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