Question

A student was asked to identify a permanent slide of mitosis. He made the following observations.
(i) Splitting of centromere and formation of daughter chromatids.
(ii) Chromatids are migrating towards the opposite poles.
The stage would be

• A. Metaphase
• B. Telophase
• C. Anaphase
• D. Prophase

Hint:

Remember key actions: Metaphase = Middle (alignment), Anaphase = Apart (splitting and migration).

Answer 1

The Correct Option is C

Step 1: Understanding the Problem:
Mitosis is divided into four main sequential stages: Prophase, Metaphase, Anaphase, and Telophase. Each stage is characterized by specific, recognizable chromosomal behaviors.
Step 2: Approach and Formula:
Identify the unique cytological markers provided in the observation and match them to the defining events of the specific mitotic phase.
Step 3: Detailed Explanation:
- Prophase: Condensation of chromatin into visible chromosomes; nuclear envelope breaks down.
- Metaphase: Chromosomes reach maximum condensation and align perfectly at the equatorial plate.
- Anaphase: The hallmark event is the sudden and simultaneous splitting of the centromeres. The sister chromatids separate to become individual daughter chromosomes and immediately begin migrating towards the opposite poles of the cell.
- Telophase: Chromosomes reach the poles and begin to decondense; nuclear envelope reforms.
The observations (splitting of centromeres and polar migration) distinctly describe Anaphase.
Step 4: Final Answer:
The stage is Anaphase.