Auxin can be bioassayed by
1. Avena coleoptiles curvature
4. Lettuce hypocotyls elongation
Dr. F. Went noted that if coleoptile tips were removed and placed on agar for one hour, the agar would produce a bending when placed on one side of freshly - cut coleoptile stumps. Of what significance is this experiment?
1. It made possible the isolation and exact identification of auxin.
2. It is the basis for the quantitative determination of small amounts of growth-promoting substances.
3. It supports the hypothesis that IAA is auxin.
4. It demonstated polar movements of auxins.
A few normal seedling of tomato were kept in a dark room. After few days they were found to have become white- coloured like albions, Which of the following terms will you use to describe them ?
Which one of the following growth regulators is known as stress hormone ?
1. Abscissic acid
4. Indole acetic acid
During seed germination its stored food is mobilized by
Through their effect on plant growth regulators, what do the temperature and light control in the plants ?
2. Closure of stomata
3. Fruit elongation
4. Apical dominance
Vernalisation stimulates flowering in -
Which one of the following generally acts as an antagonist to gibberellins ?