Question

In which stage of mitosis ,Centromere in chromosomes divide and comes in 'V' shaped ?

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

Hint:

Remember chromosome shapes during anaphase:
- V-shape: Metacentric chromosomes (equal arms).
- L or J-shape: Sub-metacentric chromosomes (unequal arms).
- J-shape: Acrocentric chromosomes (extremely unequal arms).
- I-shape Rod-shape: Telocentric chromosomes (terminal centromere).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Mitosis is a process of nuclear division in eukaryotic cells that ensures each daughter cell receives an identical set of chromosomes.
It is divided into four main sequential stages: prophase, metaphase, anaphase, and telophase.
During these stages, chromosomes undergo changes in structure, alignment, and movement.

Step 2: Detailed Explanation:
Let us trace the behavior of chromosomes during mitotic division:
- During Prophase, chromatin condenses into visible chromosomes, and the nuclear envelope begins to disintegrate.
- During Metaphase, chromosomes reach their highest level of condensation and align along the equatorial metaphase plate of the spindle.
- During Anaphase, the centromere of each chromosome splits or divides.
This splits the sister chromatids into independent daughter chromosomes.
Spindle fibers (microtubules) attached to the kinetochores contract, pulling the chromosomes toward opposite poles of the cell.
As the centromere is pulled first, the chromosome arms trail behind.
This movement causes the chromosomes to assume characteristic shapes.
Metacentric chromosomes, which have centromeres in the middle, appear as distinct 'V' shapes.
Sub-metacentric chromosomes appear as 'L' or 'J' shapes, and acrocentric chromosomes appear as rod-like structures.
- During Telophase, the chromosomes reach the poles, decondense back into chromatin, and the nuclear membrane reforms.

Step 3: Final Answer:
The centromere divides and chromosomes take on a 'V' shape during Anaphase.