Question

Bioassay of IAA is
A. Avena curvature test
B. Callus test
C. Leaf disc test
D. $\alpha$-amylase test

Answer 1

The bioassay is a delicate and precise test that tests the biological activity of hormones by measuring their effect on a particular part of the plant material. That is the testing of a biological process such as a substance 's growth reaction by using a living material such as part of a plant or plant. The bioassay of Auxin is a quantitative test since it tests the concentration of auxin in order to produce the result and the quantity of effect.

Complete answer:
The Avena Curvature Test is based on Went's (1928) experiments. Auxin is allowed to diffuse through a standard size agar block from a shoot tip or some other plant organ. Auxin can also be directly dissolved into agar. The 15-30 mm long coleoptile oat cultivated in darkness is held vertically over the water. Without injuring the primary leaf, the 1 mm tip of the coleoptile is removed. A second decapitation is carried out after 3 hours at a gap of 4 mm. The primary leaf is now taken loose and the agar block at the tip of the decapitated coleoptile is supported against it. The coleoptile can be found to have bent after 90-110 minutes. The curvature is quantified.
From these discussions we can conclude that Bioassay of IAA((Indole-3-acetic acid) is Avena curvature test.

Hence, the correct answer is option (A).

Note: The universal natural auxin is Indole 3-Acetic Acid. Kogl (1934) discovered it. Indole 3-acetaldehyde, indole 3-acetonitrile, indole 3-butyric acid (IBA), phenyl acetic acid and 4-chloro indole acetic acid are associated chemicals. Both of them have activity-like auxin. It is also found in the urine of patients suffering from pellagra, which is a condition caused by niacin deficiency.