Suppose a scientist working on a new drug for cancer developed a chemical that irreversibly breaks the hydrogen bonds in the DNA molecules within cancerous cells but leaves all of the covalent bonds intact. Hydrogen bonds are relatively weak compared to covalent bonds, and they are routinely broken and reformed as the DNA molecule is replicated in a normal cell. Their stability is nonetheless critical for maintaining certain aspects of the structure and function of the DNA molecule. Based on this scenario and your knowledge of DNA, how would this newly discovered chemical affect the "molecule of heredity" in a human cancer cell?

Question

Quizplus · Accepted Answer

Hydrogen bonds play a critical role in holding the two strands of the DNA molecule together in a double helix structure. Breaking these bonds would therefore weaken or break apart the structure of the DNA molecule and prevent it from functioning normally. Since the question states that this chemical irreversibly breaks the hydrogen bonds, it cannot be reformed during replication as they are in a normal cell, leading to constant DNA replication (answer B) or impairment of DNA function (answer A) as well. Thus, the best answer is C.

Suppose a Scientist Working on a New Drug for Cancer