F. Skoog observed that callus proliferated from the internodal segments of tobacco stem when auxin was supplied with one of the following except :
- Extract of Vascular tissues
- Coconut milk
- Abscisic acid
- Yeast Extract
Answer
(3) Abscisic acid
Solution
F. Skoog and his co-workers observed that callus proliferated from internodal segments of tobacco stem only if, in addition to auxins, the nutrient medium was supplemented with extracts of vascular tissues, yeast extract, coconut milk or DNA.
This led to the discovery of kinetin (a cytokinin). Abscisic acid was not used.
Answer: (3)