Auxin can be bioassayed by
1. Avena coleoptile curvature
4. lettuce hypocotyl elongation
What causes a green plant exposed to the light on only one side, to bend toward the
source of light as it grows?
1. Green plants need light to perform photosynthesis
2. Green plants seek light because they are phototropic
3. Light stimulates plant cells on the lighted side to grow faster
4. Auxin accumulates on the shaded side, stimulating greater cell elongation there
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 quantitative determination of small amounts of growth-promoting substances
3. It demonstrated polar movement of auxins
4. It supports the hypothesis that IAA is auxin
A few normal seedlings of tomato were kept in a dark room. After a few days they were
found to have become white-coloured like albinos. Which of the following terms will you
use to describe them?
Which one of the following growth regulators is known as "stress hormone" ?
1. abscisic acid
4. lndole acetic acid
During seed germination its stored food is mobilised by.
Phototropic curvature is the result of uneven distribution of.
Photoperiodism was first characterised in :-
Coiling of garden pea tendrils around any support is an example of
One of the synthetic auxin is