Question

F. Skoog observed that callus proliferated from the internodal segments of tobacco stem when auxins was supplied with one of the following except :

• A. Extract of Vascular tissues
• B. Coconut milk
• C. Abscisic acid
• D. Yeast Extract

Answer 1

The Correct Option is C

F. Skoog’s experiments on tobacco callus cultures showed that callus proliferation required auxin along with extracts of vascular tissues, yeast extract, or coconut milk. These extracts contain cytokinins, which, together with auxin, are essential for cell division and growth. Coconut milk is a particularly rich source of cytokinins (specifically kinetin). Abscisic acid (ABA) is a plant hormone involved in growth inhibition, dormancy, and stress responses, and it does not promote cell division and proliferation in callus cultures.