Final answer:
A double-stranded DNA molecule that is 5,000 base-pairs long will have approximately 476 full turns, which means the correct answer is (e) none of these choices.
Step-by-step explanation:
A double-stranded DNA molecule that is 5,000 base-pairs long will have a certain number of complete turns based on the structure of the DNA helix. According to the updated structure, there are 10.5 base pairs per turn of the helix, with each turn measuring 3.6 nm. Therefore, to determine the number of complete turns in a 5,000 base-pair long DNA molecule, we divide the total number of base pairs by the number of base pairs per turn:
5,000 base pairs รท 10.5 base pairs/turn = approximately 476 turns
Since this number is not one of the multiple-choice options provided, the correct choice would be (e) none of these choices.