Question

Auxin can be bioassayed by
(a)Lettuce hypocotyl elongation
(b)Avena coleoptile curvature
(c)Hydroponics
(d)Potometer

Answer 1

Hint: The techniques were done to analyze the efficiency of any substance by the effects it is producing on various organisms. The plant used in this technique is commonly called oats. It is used as a cereal grain.

Complete answer:
Auxin can be bioassayed by the Avena coleoptile elongation. The scientist in this test checked the efficiency of the auxin hormone in the Avena plant by transporting the hormone in the coleoptile of it and then observed the increase in the length of the plant.

Additional Information: -The techniques were tested by the scientist Went to analyze the efficiency of hormone auxin.
-He transported the hormone in the coleoptile of the Avena plant of which he has already decapitated (cut) the edges of the plant.
-The coleoptiles were placed in the agar gel in which auxins were transported and dispersed.
-The auxins were found to be dispersed to only one side of the coleoptile as it was seen that the block of the agar was placed unsymmetrically.
-This results in the growth and increase in the size of the diffused side of the coleoptile resulting in increased curvature.
-When the auxin was dispersed equally in all the parts of the coleoptile then the growth and curvature were proportional.
-This experiment was done to find the efficiency of the concentration of the auxin on the Avena plant.
-The major site of auxin production is apical meristem by plants
-It promotes elongation of young shoots (Indoleacetic acid), affects storage cell growth by inducing vascular cambium and secondary xylem, and promotes fruit growth
So, the correct answer is ‘Avena coleoptile curvature’.

Note: The Dutch biologist Frits Warmolt Went first described auxins and their role in plant growth in the 1920s. Phytohormones are of various types performing various functions – auxin, cytokinin, gibberellic acid, brassinosteroids, ethylene, abscisic acid, salicylic acid, and jasmonic acid.