The structure which provides an anchor for the mitotic spindle is?

Appeared in: DSSSB - 29 August 2019 (Shift-2)

Explanation

The kinetochore is a large protein complex that assembles on the centromere region of a chromosome.
Its primary function is to act as the attachment site for the microtubules of the mitotic spindle.
This connection is essential for anchoring the chromosome to the spindle apparatus.
During anaphase, the kinetochore-microtubule interaction generates the force needed to pull the sister chromatids apart to opposite poles of the cell, ensuring proper chromosome segregation.

Option B: Telomeres are protective caps at the ends of chromosomes. Their role is to maintain chromosomal integrity, not to attach to the mitotic spindle.
Option C: A polysome (or polyribosome) is a structure involved in protein synthesis, consisting of multiple ribosomes translating a single mRNA strand simultaneously.
Option D: Lysosomes are organelles that contain digestive enzymes and are responsible for breaking down cellular waste and foreign material. They are not involved in cell division.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Cellular structures involved in mitosis as background academic context rather than a clinical decision trigger.
Several important chemotherapy drugs, known as antimitotic agents, target the function of the mitotic spindle. Understanding the kinetochore's role is key to understanding how these drugs work.
Drugs like Vinca alkaloids (e.g., vincristine, vinblastine) prevent the assembly of microtubules, while Taxanes (e.g., paclitaxel) prevent their disassembly. Both actions disrupt spindle function, arrest cells in mitosis, and lead to cell death, which is particularly effective against rapidly dividing cancer cells.
Nursing care for patients on these drugs involves vigilant monitoring for side effects related to the disruption of cell division in healthy tissues, such as myelosuppression (low blood counts), peripheral neuropathy (nerve damage), and alopecia (hair loss).

How to Approach the Question

First, identify the key concepts in the question: 'anchor' and 'mitotic spindle'. This points to the process of cell division (mitosis).
Recall the major structures involved in chromosome segregation during mitosis.
Evaluate each option based on its known biological function.
Kinetochore is a protein structure on the chromosome for spindle attachment. This directly matches the 'anchor' function described.
Telomere is related to chromosome ends and protection, not spindle attachment.
Polysome is involved in protein synthesis, unrelated to mitosis mechanics.

Concept Tested & Keywords

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E6 Anatomy Grays 43e Vol 1 Part 1 p. 47-49

E6 Physiology Guyton 4SAE Part 1 p. 65-67

Practise the full DSSSB - 29 August 2019 (Shift-2)

Attempt every question from this paper in a timed mock, then review the full solution for each one.