Which one of the following represents a mismatch or incorrect description? A prophase: chromosomes become more tightly coiled B telophase: chromosomes line up and separate C anaphase: there is movement of the chromosomes to the poles
The correct answer and explanation is:
The incorrect description is B telophase: chromosomes line up and separate.
Explanation:
- Prophase: This is the first stage of mitosis where the chromosomes begin to condense and become more tightly coiled. During prophase, the nuclear envelope starts to break down, and the spindle fibers begin to form. The chromosomes become visible as distinct structures, making this description accurate.
- Telophase: This is the final stage of mitosis, not the stage where chromosomes line up and separate. During telophase, the separated chromatids reach opposite poles of the cell, and the nuclear envelope reforms around each set of chromosomes, resulting in the formation of two distinct nuclei. The chromosomes begin to de-condense, and the cell is preparing for cytokinesis. Therefore, the statement that “chromosomes line up and separate” is incorrect for telophase, as this actually occurs during metaphase and anaphase.
- Anaphase: This is the stage when the sister chromatids, which were previously attached at the centromere, are pulled apart towards opposite poles of the cell. The movement of the chromosomes to the poles is facilitated by the spindle fibers. This description is accurate, as anaphase is characterized by the physical separation of chromatids.
In summary, telophase is the stage where the chromosomes de-condense and the nuclear membrane reforms, making it an incorrect description to say that chromosomes “line up and separate” during this phase. That event occurs earlier during metaphase and anaphase.