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 Concept: Mitosis is divided into four main stages (Prophase, Metaphase, Anaphase, Telophase), each characterized by specific chromosomal movements.
Step 2: Key Formula or Approach: Identify the unique defining cellular events listed in the observations and match them to the corresponding phase of the cell cycle.
Step 3: Detailed Explanation:
In Prophase, chromosomes condense, and the nuclear envelope breaks down.
In Metaphase, chromosomes align flawlessly at the cellular equator (metaphase plate).
In Anaphase, the centromere holding the sister chromatids together undergoes sudden splitting. The newly separated sister chromatids (now considered individual daughter chromosomes) are rapidly pulled apart and migrate toward opposite poles of the cell by the shortening spindle fibers.
In Telophase, chromosomes decondense at the poles, and nuclear envelopes reform.
The observations provided exactly describe the key events of Anaphase.
Step 4: Final Answer: The stage identified is Anaphase.