Question

19. Below is a model of DNA.Which process takes place before mitosis occurs in a cell containing this DNA?Covalent bonds at 4 break and two double-stranded DNA molecules are synthesized.Covalent bonds at 2 and 6 break and one double-stranded DNA molecule results.Hydrogen bonds break at 6 and one double-stranded DNA molecules results.Hydrogen bonds at 5 break and two double-stranded DNA molecules are synthesized.

Answer 1

Explanation:

Remember that before the cell decides to enter mitosis, the cell is in interphase. One of the phases of interphase is the synthesis (S) phase where DNA is replicated. Semiconservative DNA replication involves two steps. In the first step, the DNA is unwound to separate the two template strands and make them available for base pairing. Remember that pairs of complementary bases form hydrogen bonds that hold the two strands of the DNA double helix together.

Thus, according to this information and the following picture given in the problem:

we can conclude that the correct answer is:

Answer:

Hydrogen bonds at 5 break and two double-stranded DNA molecules are synthesized.