Question 9
In tissue culture, what is the callus?
The right answer is the one marked above.
A new tissue that forms on the tissue piece, from which roots and shoots grow. It is the second of the four steps, and the shoots are separated from it afterwards.
The gelatinous medium confuses the callus with what it grows in, which is made gelatinous by agar and also carries sucrose, mineral salts, vitamins and growth substances. Sterility and hardening are real parts of the process but neither is a tissue.