The 3' end of DNA a refers to the end that has a hydroxyl group attached to the number 3 carbon. b attaches to the 5' phosphate group of the incoming nucleotide. c always has thymine attached to it. d usually has guanine attached to it. e a and b

The answer is E) options a and b are correct.

Explanation:

The 3' end is the one that has a hydroxyl (OH) group on the deoxyribose of the 3' carbon of the deoxyribose and it attaches to the 5' phosphate group of the incoming or newly formed nucleotide.

Option E (A and B)

Explanation:

The DNA is a polynucleotide having a specific sequence of deoxyribonucleotide units covalently joined through 3',5'-phosphodiester bonds. Hence, the 3' end of DNA refers to the third carbon on the deoxyribose sugar with a hydroxyl group attached while it also attaches to the phosphate group carried by the fifth carbon of the deoxyribose sugar present on the incoming nucleotide.

Thus, both options A and B describes the 3' end of DNA.

i think the answer would d