Question

A few years ago, the labels from one class section's experimental treatments plants fell off in the greenhouse and got swept away! One group was the only group in the section to test the effects of indole acetic acid (IAA) on bean plants. The IAA group applied lanolin paste to one side of their bean stems. What should they look for in order to identify their experimental plants from other groups

Answer 1

Answer:

The group needs to find signs of apical dominance, growth in response to light, vascular tissue differentiation, formation of lateral and adventitious roots, etc.

Explanation:

Lanolin is a solvent used to study physiological processes in plants by diluting hormone growth regulators (in this case, indole acetic acid). Indole acetic acid (IAA) is the most important auxin hormone in plants. Auxins are essential plant hormones synthesized in expanding shoot tips that move down the stem to the roots. These hormones coordinate cell division, elongation and identity during plant body development. IAA hormone is well known to regulate different plant developmental processes including, among others, apical dominance (where the central stem grows more strongly than other lateral stems), tissue differentiation, stem elongation, phototropism (growth in response to light) and gravitropism (response to gravity). For instance, under the application of IAA, it is expected that bean stems grow to imitate the response to light (phototropism) by bending away from the side where lanolin was applied.