Question

darcy graphed the mass of the dna in a cells nucleus over time, and noticed that the dna mass changed. which statement best explains the increase in dna mass at the beginning of hours 12 and 36? a the dna unwinds and separates into two daughter cells. b the dna replicates prior to cell division. c the cell completed a second round of cell division, segregating the dna into four daughter cells. d the cell grows and increases the volume of the cytoplasm.

Explanation:

During the cell cycle, DNA replication (synthesis phase) occurs before cell division (mitosis or meiosis). This doubles the DNA mass. Option A is incorrect as DNA separation into daughter cells would decrease mass. Option C is wrong as segregation into four cells would reduce mass. Option D is about cytoplasm, not DNA mass. Only DNA replication (Option B) explains the increase in DNA mass.

Answer:

B. The DNA replicates prior to cell division.