The first phase of cell division is?

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2021

Explanation

Prophase is the first stage of mitosis, the process of nuclear cell division in eukaryotic cells.
During prophase, the chromatin (a complex of DNA and proteins) condenses and coils to form visible chromosomes.
The nuclear envelope, which encloses the nucleus, starts to break down, and the mitotic spindle begins to form from the centrosomes.
This preparatory phase is the longest of the four mitotic stages, setting the stage for chromosome segregation.

Option A: Anaphase is the third phase of mitosis, occurring after prophase and metaphase.
Option B: Metaphase is the second phase of mitosis, following prophase.
Option D: Cell division is a sequential process with distinct, ordered phases. It does not begin with all phases simultaneously.

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 to oncology. Cancer is characterized by uncontrolled cell division, often due to mutations in genes that regulate the cell cycle checkpoints.
Many chemotherapy drugs, known as antimitotic agents (e.g., Vinca alkaloids, Taxanes), specifically target the mitotic phase. They disrupt the formation or function of the mitotic spindle, arresting cancer cells in mitosis and leading to their death (apoptosis).
What if? If a cell has a mutation that prevents it from properly completing prophase (e.g., the spindle doesn't form correctly), a functional cell cycle checkpoint (the spindle assembly checkpoint) should arrest the cell cycle, preventing it from proceeding to anaphase. This prevents aneuploidy (abnormal chromosome numbers) in daughter cells. If this checkpoint fails, it can contribute to genetic instability and cancer progression.

How to Approach the Question

Identify the core question: The question asks to identify the 'first phase' of cell division.
Recall the stages of mitosis. A helpful mnemonic is PMAT: Prophase, Metaphase, Anaphase, Telophase.
Based on the PMAT mnemonic, 'P' for Prophase is the first stage.
Evaluate the given options: Anaphase (A), Metaphase (M), and Prophase (P).
Select the option that corresponds to the first letter of the mnemonic, which is Prophase.
Eliminate the other options based on their position in the sequence (Metaphase is second, Anaphase is third) and logical impossibilities ('All phases').

Concept Tested & Keywords

QfqZHhWe_Dp0Fcng5RFUPB

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

E6 Physiology Guyton 4SAE Part 1 p. 66-68

E6 Pathology-Textbook of PATHOLOGYHarsh Mohan Part 1 (1-214) p. 49-51

Practise the full RUHS, Jaipur, PB B.Sc Nursing Entrance-2021

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