Q. Correct chronological order during callus formation is :
(a) Explant → Cell division → Callus → Addition of Cytokinin → Cells acquire meristematic property
(b) Callus → Explant → Cell division → Addition of Cytokinin → Cells acquire meristematic property
(c) Callus → Cell division → Explant → Addition of Cytokinin → Cells acquire meristematic property
(d) Explant → Callus → Cell division → Addition of Cytokinin → Cells acquire meristematic property
Solution : Correct option : A In callus culture, a plant tissue or an explant is taken and is introduced into the medium for rapid cell division. It forms callus and further addition of phytohormones like cytokinin in required amounts will result in meristematic activity.