Question

Dr.F went noted that if coleoptile were removed and placed on agar for one hour, the agar would produce a bending when placed on one side of freshly- cut - coleoptile stumps. Of what significance is this experiment ?

Answer 1

Answer:

Explanation:

It supports the hypotheses that IAA is auxin it demontrated polar movement of auins It made posible the isolation and exact identification os auxinIt is the basis for quantitative determation of small amounts of growth -promoting substances

Answer 2

Bioassay of auxin

Explanation:

• There are various bioassays to determine the concentration of auxin hormone in the plant
• The Avena coleoptile test is a bioassay firstly done by F. W. Went,it is for IAA (indole-3-acetic acid)
• It measures the angle of the curvature of a decapitated coleoptile after placing an agar block containing auxin on one side
• It is seen that when coleoptile tips are placed on agar, agar produced bending when placed on one side of freshly cut coleoptile stumps which is due to the polar movement of auxin in the stem
• Polar transport proceeds from cell to cell,auxin exit the cell through plasma membrane,diffuses across compound middle lamella and enters to other cell through plasma membrane
• Polar transport requires energy and is gravity independent