This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Molecular Biology Techniques, Subject name: Biochemistry
Function of endonucleases: 
Select and explain. 
A. Cut DNA at specific DNA sequences, B. To point out the coding regions, C. Enhancers, D. To find out antibiotic resistance
A: Cut DNA at specific DNA sequences
Answer: A: Cut DNA at specific DNA sequences 
Explanation: Ans. A. Cut DNA at specific DNA sequences(Ref: Harper 31/e page433)Restriction endonuclease cut DNA at specific palindromic sites.These enzymes are isolated from bacteria.They restrict the entry of phages into the bacteria.