Answer:
Atmospheric oxygen is too reactive
Explanation:
 
        
             
        
        
        
Q1-  D
q2- C
q3- B 
I am assuming you only need one answer for each, good luck! 
        
                    
             
        
        
        
The complementary sequence of nucleotides found on the other strand of DNA is <u>ACGAAT</u> when one strand in a segment of a gene has the base sequence TGCTTA.
<u>Explanation:</u>
Deoxyribonucleic acid is the one which carries the genetic information from the parent to the offspring.  During DNA replication one strand of DNA replicates to produce another strand.         
The DNA molecule have a anti-parallel structure and the two strands run in opposite direction. If in one strand in a segment of a gene has the base sequence TGCTTA the complementary sequence of nucleotides found on the other strand of DNA will be ACGAAT. 
 
        
             
        
        
        
Answer:
the diagram explains the process of DNA digestion and DNA ligation, which is usually used in molecular cloning techniques  
Explanation:
Molecular cloning can be defined as the process used to synthesize multiple copies of a particular DNA fragment. Molecular cloning requires the insertion of a foreign DNA fragment into an appropriate vector (e.g., a plasmid) through the action of specific enzymes that serve to cut and ligate DNA fragments. DNA digestion and DNA ligation use specific restriction enzymes and DNA ligases, respectively, in order to insert the foreign DNA fragment. For this purpose, restriction enzymes that generate single-stranded overhangs are preferred to create sticky ends which bind by complementary base pairing. Subsequently, a DNA ligase enzyme joins the DNA fragments together in order to create recombinant DNA molecules. DNA Ligation is often achieved by using a specific T4 DNA ligase, while there are many restriction enzymes that generate sticky-ends (e.g., BamHI, EcoRI, BaI228I, etc).
 
        
             
        
        
        
On my work the answer was D ..