Question

Avena coleoptile is for which of the following hormones?
A. GA
B. ABA
C. IAA
D. NAA

Answer 1

Hint:Guthrie (1940) found that the contents of auxin increased in tubers that had ended their dormancy by ethylene chlorohydrin therapy using an Avena bio-assay.

Complete answer:
Avena is a kind of grass family Eurasian and African plants. Collectively referred to as oats some plants have been grown as a source of food for humans and animals for thousands of years. It is common across Europe, Asia and northwest Africa. In many parts of the world many plants have become naturalistic and are considered to compete with the production of crops as invasive weeds. While they are small and difficult to harvest in most species, all oats seeds are edible. Coleoptile is protective covers of emerging shoots in grasses in which some shoot apex and leaf primordial of monocot remains enclosed.
Avena coleoptile test is a bioassay for indole-3-acetic acid (IAA). Bioassay is a sensitive and precise test to assess hormones' biological activity on a specific part of the plant material. Different organic tests are performed to assess the concentration in plants of the auxin hormone, like avena coleoptile test, curvature of the split pea stem and root cress testing. The avena coleoptile test can calculate the angle of curvature of a decapitated coleoptile.

Thus, the correct answer is option C. i.e., IAA.

Note:The Avena Coleoptile Test keeps the physical demands and of manipulation characteristic of all elongation tests. The key characteristic of this test is that it makes it possible to calculate the elongation of coleoptile segments as directly proportional to the concentration rather than the logarithm of the indole acetic acid concentration.