Q. Which of the following shows correct chronological order of the events occurring during callus culture?
A) Callus $\rightarrow$ Cell division $\rightarrow$ Explant $\rightarrow$ Addition of cytokinin $\rightarrow$ Cells acquire merstematic property
B) Explant $\rightarrow$ Callus $\rightarrow$ Cell division $\rightarrow$ Addition of cytokinin $\rightarrow$ Cells acquire meristematic property
C) Explants $\rightarrow$ Cell division $\rightarrow$ Callus $\rightarrow$ Addition of cytokinin $\rightarrow$ Cells acquire meristematic property
D) Callus $\rightarrow$ Explant $\rightarrow$ Cell division $\rightarrow$ Addition of cytokinin $\rightarrow$ Cells acquire meristematic property
Explanation
In callus culture, cell division in explant forms a callus. Callus is irregular unorganized and undifferentiated mass of actively dividing cells. Darkness and solid medium gelled by agar stimulates callus formation. The culture medium contains growth regulators auxin 2, 4-D and often a cytokinin like BAP. Both of these growth regulators stimulate meristematic property in callus.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.