Question

Avena coleoptile test to find out the quantity of growth promoting hormones was discovered by
A) F. W Went
B) L. J Odus
C) K. V Thimann
D) F. Skoog

Answer 1

Hint: The Avena curvature test was first done by a Dutch researcher. He was named director of the Missouri Botanical Garden and professor of botany at Washington University in St Louis in 1958, at a time when he had established himself as an internationally recognised specialist on plant growth.
The bioassay is a precise, sensitive test that measures the influence of hormones on a specific component of the plant's material to evaluate their biological activity. Avena curvature test, split pea stem curvature test, cress root inhibition test, and more bioassays are available to determine auxin hormone levels in plants.

Complete answer:
Option A: F. W. Went conducted the Avena curvature experiment. The ability of auxin to stimulate shoot growth or inhibit root growth was tested using a bioassay. After applying auxin in agar on one side of the plant, the angle of curvature of the cut ends of the coleoptile is determined in the Avena curvature test.
So option A is correct.
Option B: Auxin was extracted from the tips of coleoptiles of oat seedlings by F.W. Went. Ethylene causes plant organ senescence and abscission, particularly in leaves and flowers.
So option B is not correct.
Option C: Kenneth Vivian Thimann was an English-American plant physiologist and microbiologist who made significant contributions to agriculture and horticulture through his research on plant hormones. Auxin, the first known plant hormone, was extracted and its structure identified by him.
So option C is not correct.
Option D: Folke Karl Skoog was a pioneer in the science of plant growth regulators, particularly cytokinins. He was an American plant physiologist of Swedish heritage. Skoog was a National Medal of Science laureate.
So option D is not correct.

So option A is the correct answer.

Note:
The test is conducted with etiolated coleoptile oats in unique perspex trays in diffuse daylight. The coleoptiles, with the primary leaves intact, are put in grooves on the trays and sliced to a size of 10 mm in four series of six coleoptiles each. Only the lower halves of each set of apical cut surfaces are covered with the test substance on an agar strip.After a four hour stay in the dark on moist Petri dishes, the coleoptile cylinders are graphed in shadow on a 35 mm picture film. An increased projection of the shadow graphs is used to determine the curvatures.