Final answer:
The statement that DNA cannot be unwound without breaking certain parts is false. Helicase unwinds DNA and topoisomerase enzymes cut and rejoin the DNA backbone to relieve tension without breaking the helix into individual nucleotides.
Step-by-step explanation:
True or False: DNA cannot simply be unwound without breaking certain parts. This statement is false. DNA replication involves the opening of the double helix at the origin of replication by enzymes such as helicase that unwind DNA. However, this unwinding causes supercoiling or twisting of the DNA further down the strand. To relieve this tension, another set of enzymes called topoisomerases cut the phosphate backbone of the DNA to allow it to unwind without breaking into individual nucleotides, then reconnect the DNA. In contrast, replication is facilitated by polymerase that moves along the helix, unwinding the DNA ahead of the replication fork, and rewinding it behind, ensuring that DNA integrity is maintained during this process. DNA binding proteins also aid in preventing the complete unwinding of the helix.