Which of the following statements about the 5ʹ end of a polynucleotide strand of DNA is correct?
A) The 5ʹ end has a hydroxyl group attached to the number 5 carbon of ribose.
B) The 5ʹ end has a phosphate group attached to the number 5 carbon of ribose.
C) The 5ʹ end has thymine attached to the number 5 carbon of ribose.
D) The 5ʹ end has a carboxyl group attached to the number 5 carbon of ribose.
E) The 5ʹ end is the fifth position on one of the nitrogenous bases.
Answer: B) The 5ʹ end has a phosphate group attached to the number 5 carbon of ribose.