6. Cleavage of DNA by EcoRI endonuclease results in the formation of

A. two 3′-OH ends and two 5′-phosphate ends
B. one 3′-OH end and one 5′-phosphate end
C. two 3′-phosphate ends and two 3′-OH ends
D. one 3′-OH end and two 5′-phosphate end

7. Which of the following amino acids interact with the DNA or RNA backbone (i.e. phosphate)?

A. Ile and Val
B. Lys and Arg
C. Leu and Ala
D. Cys and Met