The direction of the transport of auxins is

Which of the following ions is pumped into the apoplast by auxin during cell growth?

Substances which originate at the tip of the stem and control growth elsewhere are

After a series of experiments,it was concluded that the ....$A$.... of coleoptile was the site of transmittable influence that caused the bending of the entire coleoptile.

What happens when auxin is applied to the tip of a cut stump?

$NAA$ is