Avena coleoptile test to find out the quantity of growth promoting hormones was discovered byA) F. W WentB) L. J OdusC) K. V ThimannD) F. Skoog

The correct answer is A) F. W. Went.
The Avena coleoptile test was a groundbreaking experiment developed by F. W. Went in 1928. Went used this test to discover and demonstrate the presence of auxins, a class of plant growth hormones that promote cell elongation and are crucial in the regulation of plant growth.
• Avena refers to the genus of oats, and coleoptile is the protective sheath covering the emerging shoot of a grass seedling. Went used the Avena coleoptile as a model system to study the effect of growth hormones on plant growth.
• Went's experiment involved placing the coleoptiles of oat plants in a solution containing a growth-promoting substance. He observed that the coleoptile growth was significantly affected, which led him to conclude that the substance was a hormone that influenced plant growth. This substance was later identified as auxin.
Why the other options are incorrect:
• B) L. J. Odus: L. J. Odus is not associated with the discovery of growth-promoting hormones or the Avena coleoptile test.
• C) K. V. Thimann: K. V. Thimann contributed significantly to plant hormone research, particularly in the study of auxins, but he was not the one who discovered the Avena coleoptile test.
• D) F. Skoog: F. Skoog was an important figure in plant physiology and made significant contributions to the study of plant hormones, especially cytokinins, but he did not discover the Avena coleoptile test.
The Avena coleoptile test to identify the presence and effects of growth-promoting hormones was discovered by F. W. Went. Therefore, the correct answer is A) F. W. Went.