In which among the following phases of Mitosis do the chromosomes reach the poles of their respective spindle… - AIIMS Raipur lecturer 2021

AIIMS Raipur lecturer 2021

Applied Physiology

Easy

Appeared in: AIIMS Raipur lecturer 2021

Explanation

Telophase is the final stage of mitosis, where the key event is the arrival of the separated chromosomes at the opposite poles of the cell.
Once the chromosomes reach the poles, they begin to decondense, and a new nuclear envelope forms around each set, marking the end of nuclear division.
The question specifically asks when the chromosomes reach the poles, which is the defining characteristic that marks the beginning of Telophase and the end of Anaphase.

Option A: Anaphase is the phase during which the sister chromatids separate and move toward the opposite poles. They have not yet reached their final destination.
Option B: In Metaphase, the chromosomes are aligned at the center of the cell, along the metaphase plate (equator), not at the poles.
Option C: Prophase is the initial stage where chromatin condenses into visible chromosomes and the nuclear envelope breaks down. The chromosomes are not yet organized at the poles.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Phases of Mitosis as background academic context rather than a clinical decision trigger.
Understanding the cell cycle is fundamental in oncology. Cancer is characterized by uncontrolled cell division, often due to defects in cell cycle checkpoints.
Many chemotherapy drugs, known as antineoplastics, target specific phases of mitosis to halt the proliferation of cancer cells. For example, Vinca alkaloids (like vincristine) disrupt spindle formation, arresting cells in Metaphase, while Taxanes (like paclitaxel) stabilize the spindle, preventing chromosome separation in Anaphase.
What if? If a cell had a mutation that prevented the spindle fibers from shortening, the chromosomes would fail to separate during Anaphase, leading to a mitotic arrest and potentially cell death (apoptosis) or the formation of an aneuploid cell (abnormal chromosome number), which is a hallmark of many cancers.

How to Approach the Question

First, identify the core concept of the question, which is the sequence of events during mitosis.
Analyze the specific action described: 'chromosomes reach the poles'.
Recall the key events of each phase of mitosis: Prophase (condensation), Metaphase (alignment at equator), Anaphase (separation and movement towards poles), and Telophase (arrival at poles and decondensation).
Differentiate between 'moving toward' the poles (Anaphase) and 'reaching' the poles (Telophase).
Select the phase that corresponds to the completion of the chromosome's journey, which is Telophase.

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