Question

Complete dissociation of chromatin material in the nucleus is termed as

• A. Karyorhexis
• B. Karyolysis
• C. Pyknosis
• D. Nucleolysis

Hint:

Remember the progression of nuclear death:
Pyknosis (Shrinkage) $\rightarrow$ Karyorrhexis (Fragmentation) $\rightarrow$ Karyolysis (Dissolution/Dissociation).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Cell death (necrosis) is accompanied by a sequence of characteristic structural changes in the nucleus, which can be observed histopathologically.

Step 2: Detailed Explanation:
When a cell undergoes necrosis, the nucleus displays three classic sequential morphological changes:
1. Pyknosis: This is the initial stage, characterized by nuclear shrinkage and increased basophilia. The chromatin condenses into a solid, dark, structureless mass.
2. Karyorrhexis: Following pyknosis, the condensed nucleus undergoes fragmentation, breaking apart into small, dark chromatin dust particles scattered throughout the cytoplasm.
3. Karyolysis: This is the final stage of nuclear destruction.
In karyolysis, the chromatin material undergoes complete enzymatic dissolution and biochemical degradation, primarily driven by DNases and other lysosomal hydrolases.
As the DNA is digested, the staining intensity of the nucleus fades until it completely disappears from the cell, leaving an empty, necrotic cell outline.
Therefore, the complete dissociation and dissolution of chromatin material in the nucleus is termed karyolysis.

Step 3: Final Answer:
The complete dissociation of chromatin material in the nucleus is termed Karyolysis.