Question

Gametoclonal variations from changes in chromosome number/structure may arise due to which of the following:
A. Polyploidy
B. Aneuploidy
C. Translocations and inversions
D. Reduction division
Choose the correct answer from the options given below:

• A. A, C and D only
• B. B, A and D only
• C. C, B and A only
• D. D, C and B only

Hint:

Variations are Errors. Meiosis (Reduction Division) is the Standard Procedure, so it doesn't count as an "error" or variation source here.

Answer 1

The Correct Option is C

Concept: Gametoclonal variation refers to the genetic variation observed in plants regenerated from gametic cultures (like pollen or ovules). This variation can be due to changes in chromosome count or physical structure.

Step 1: Numerical Variations (A and B).
Changes in the total number of chromosomes are a major source of variation. This includes Polyploidy (A) (extra whole sets) and Aneuploidy (B) (gain or loss of individual chromosomes).

Step 2: Structural Variations (C).
Physical damage or rearrangement of the DNA strands leads to variations like Translocations and inversions (C). These change the gene order and can significantly alter the plant's phenotype.

Step 3: Eliminating Normal Processes.
Reduction division (D) is another name for Meiosis. This is a normal biological process required to form gametes in the first place, not an abnormal change in number or structure that causes "variation" in the context of tissue culture instability.