Question

In plant tissue culture formation of organ primordia-like shoot or root in callus cells is called -

• A. Dedifferentiation
• B. Redifferentiation
• C. Somatic embryogenesis
• D. Regeneration

Hint:

Memorize the sequence in organogenesis via callus culture: {Explant (Differentiated)} \(\rightarrow\) {Dedifferentiation} \(\rightarrow\) {Callus (Undifferentiated)} \(\rightarrow\) {Redifferentiation} \(\rightarrow\) {Organs (Differentiated)}.

Answer 1

The Correct Option is B

Step 1: Concept Overview:
The question identifies the term for the process by which undifferentiated callus cells develop specialized structures, such as shoot or root primordia.
Step 2: Term Definitions:
Consider the following definitions within plant tissue culture:
Dedifferentiation: Specialized cells from an explant revert to an unorganized, proliferative state (callus).
Redifferentiation: Callus cells differentiate, forming specialized cells, tissues, and organized structures like organ primordia (shoots, roots). This aligns directly with the question.
Somatic embryogenesis: Somatic cells form zygotic embryo-like structures (bipolar with shoot and root poles), unlike the formation of just a shoot or root primordium.
Regeneration: Overall development of a plant from cell or tissue culture. Redifferentiation is the specific cellular process causing organ formation during regeneration.
Step 3: Conclusion:
The formation of organ primordia from callus cells is redifferentiation.