Use the figure to answer the question below.

In the figure, why does the amount of DNA in nucleus decrease from IV to V?

Question

Use the figure to answer the question below.

In the figure, why does the amount of DNA in nucleus decrease from IV to V?

BlackTom AI · Accepted Answer

To begin analyzing the figure, observe how the labeled regions change in DNA content across the stages shown.
Option 1: 'cells have lost chromosomes' — This is not accurate for a standard cell cycle diagram; lost chromosomes would imply an abnormal event like a chromosome loss, which is not what is depicted here. The chart shows normal progression, not chromosomal loss.
Option 2: 'cells have gone through mitosis and cytokinesis' — This is the plausible explanation. After mitosis and cytokinesis, the original nucleus partitions its DNA into two daughter cells, so the DNA content in a single nucleus decreases as the cell completes division. In the diagram, the drop from IV to V aligns with the completion of cytokinesis in the second cycle, resulting in reduced DNA content per nucleus.
Option 3: 'cells are in S phase' — During S phase, DNA is replicated, so the amount of DNA in the nucleus increases, not decreases. The graph would show an upward slope or plateau, not a drop, if the cells were in S phase.
Option 4: 'cells are in G2 phase' — G2 occurs after DNA replication but before mitosis; the DNA content remains the same as after S phase. A decrease at IV to V would not be expected in G2, so this choice contradicts the typical DNA-content pattern of the cell cycle.
In summary, the only option that appropriately explains a reduction in nuclear DNA content between those stages is that the cells have undergone mitosis and cytokinesis, which physically partitions and reduces DNA content per nucleus.

Use the figure to answer the question below. In the figure, why does the amount of DNA in nucleus decrease from IV to V?单项选择题

类似问题

In which phase of the cell cycle does DNA replication (making a second copy of DNA) occur?

Question at position 7 The majority of the lifespan of a cell is spent as this phaseinterphaseanaphaseprophasetelophase

At what stage of the cell cycle would you expect there to be twice the amount of DNA as normal?

Question at position 91 In eukaryotes the replication of chromosomal DNA occurs during:G2 phaseanaphaseG1 phaseprophaseS phase

If A, B, and C represent G1, S, and G2, respectively, then which phase of the cell cycle would you predict to last the longest in duration? Use the data shown in the left panel (Cells without treatment graph) to answer this question.

After S phase of interphase, each chromosome contains two sister chromatids.

Chromosome replication in a somatic cell takes place during

During what portion of the cell cycle does interphase occur?

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单